Where Science and Faith Converge
  • Did Neanderthals Make Jewelry?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Sep 28, 2016

    I was a troublemaker in high school. And that meant I spent more than my fair share of time in Mr. Reynold’s office—our school’s vice principal.

    It wasn’t long before we developed a bit of a dance that played out each time I was summoned to his office. Mr. Reynolds would accuse me of some misdeed (for which he usually had ample evidence) and I would respond with an elaborate defense, hoping to convince him of my innocence. I quickly learned that if my excuse was to stick, every detail of my story had to hang together.

    A few days ago, I was reminded of my conversations with Mr. Reynolds when I learned about recent work by a large team of collaborators from the US, UK, Germany, and France. Based on their research efforts, these paleoanthropologists claim to have new evidence that Neanderthals produced body ornaments and, hence, possessed the capacity for symbolism and advanced cognitive abilities—just like us.1 Yet, this story doesn’t hang together when considering other details about Neanderthal biology and natural history.

    Take it from someone who has experience concocting stories—the claim that Neanderthals displayed symbolism doesn’t pan out.

    The Grotte du Renne Cave Site

    During a recent visit to the well-studied Grotte du Renne cave site in central France, these research collaborators unearthed previously unknown hominid bone fragments. These pieces of bones were morphologically nondescript. Yet these investigators found the bones to be highly informative, thanks to the application of newly developed, sophisticated techniques that allowed them to characterize ancient protein and mitochondrial DNA fragments associated with the bones. These ancient biomolecules indicated that the bones came from a Neanderthal infant.

    This discovery is significant because these newly discovered bone fragments were recovered in the same layers that contain beads made from animal teeth, shells, and ivory. These “necklaces” serve as markers for symbolic capacity—a property that many people think defines modern humans. Symbolic capacity is a behavioral feature that causes a number of anthropologists to think that modern humans are behaviorally unique and exceptional.

    The Grotte du Renne site contains 15 archaeological layers spanning about 12 feet in depth. Neanderthals and modern humans occupied this cave at various times between 28,000–45,000 years ago. The top layers—which are the most recent—contain artifacts produced by modern humans. However, the most interesting layers are VIII, IX, and X. These layers contain Neanderthal remains, with layer X harboring markers for symbolism. This layer dates to about 40,000 years in age. If this data is accepted at face value, it indicates that these hominids evolved the capacity for symbolic behavior and possessed advanced cognitive abilities just before their extinction.

    Neanderthals appeared about 250,000 years ago and became extinct around 40,000+ years ago. The archaeological record indicates that for most of their existence Neanderthals behaved in a relatively unsophisticated manner compared to modern humans. (This behavior is described as the Mousterian culture.) However, based on the findings from the Grotte du Renne, some paleoanthropologists have argued that around 40,000 years ago—the time of modern humans’ arrival in Europe and right before Neanderthals’ disappearance—these hominids evolved the capacity for modern behavior and with it, symbolic thought. (Paleoanthropologists refer to this behavior as the Châtelperronian culture.)

    Neanderthal Symbolism and the RTB Human Origins Model

    The existence of the Châtelperronian culture means that modern humans aren’t behaviorally unique. From an evolutionary vantage point, it implies that advanced cognitive abilities evolved independently in modern humans and Neanderthals (with the antecedents for symbolism residing with the direct evolutionary ancestor of modern humans and Neanderthals).

    If this insight stands, it undermines the view of humanity espoused by Scripture—namely, that human beings uniquely bear God’s image—and, specifically the RTB human origins model (detailed in the expanded and updated edition of Who Was Adam?), which regards symbolism as an aspect of the image of God.

    So what did this research team discover and what conclusions can they legitimately draw from their discoveries?

    It is also worth noting that every previous claim for Neanderthal symbolism from the archaeological record has failed to withstand scientific scrutiny.

    Characterization of the Grotte du Renne Bone Fragments

    The research team saw the discovery of the morphologically indistinct bone fragments in layer X as an opportunity to try out new methods they recently developed, designed to recover and characterize ancient protein fragments from fossil specimens. They hope that these fragments (which are much more likely to be present in ancient bones than DNA) will provide insight into the taxonomic identity of the bone fragments, but also help scientists gain insight into the biology and natural history of ancient organisms. (The study of ancient proteins is called paleoproteomics).

    Early work in paleoproteomics demonstrates that fragments of certain forms of collagen can be used to identify large bodied genera. These researchers extracted proteins from 196 bone fragments found in layer X. Of those, 28 possessed a collagen fingerprint that identified them as coming from a hominid.

    The researchers then extracted more than 70 different proteins from 3 of the 28 bone pieces. As is true for all studies involving ancient biomolecules, contamination by biomolecules from the environment and human handlers is a real concern. Because of this complication, the researchers employed an elaborate set of steps to discriminate endogenous proteins from contaminants, including:

    • Analyzing extraction blanks: Proteins found in both the blanks and samples must be contaminants introduced in the handling of the bones.
    • Assessing chemical alteration of proteins: As proteins age, they undergo characteristic chemical changes (such as glutamine and asparagine deamidation). Proteins that don’t show these transformations must be contaminants.
    • Searching protein databases: The researchers compared the amino acid sequences of the extracted proteins with amino acid sequences of proteins produced by nonhuman animals. Matches were taken as contaminants.

    Through this process, the researchers discovered a number of collagens and non-collagen proteins that appeared to be authentic. Many of these extracted proteins are produced by cells during bone growth. Isotope analysis of collagen extracted from the hominid bones indicate that they came from an individual whose chief diet was breast milk. On this basis, the researchers concluded that the fragments were from an infant. They then found that the amino acid sequences of the extracted collagens matched collagen amino acid sequences found in both Neanderthals and Denisovans. (The researchers deduced the amino acid sequences of hominid collagens from the Neanderthal and Denisovan genomes.)

    Additionally, the researchers recovered mitochondrial DNA (mtDNA) from one of the bone pieces. The sequence of this DNA aligns with Neanderthal mtDNA, providing confirmatory evidence that the bone fragments came from a Neanderthal.

    Finally, the researchers used carbon-14 dating of extracted collagen to determine the age of the bone pieces at 37,000–39,000 years bp (before the present).

    On the basis of all of these results, they concluded that the bone pieces came from a Neanderthal infant that was buried in the cave around 38,000 years ago, and more broadly that Neanderthals produced the “necklace beads” found in layer X.

    It is important to point out that this is not the first time anthropologists have arrived at this conclusion. Anthropologists have long had evidence from morphologically informative fossils for the co-occurrence of Neanderthal remains and symbolic artifacts in layer X. The novelty of this work centers around the power of paleoproteomics and ancient DNA analysis to provide key insight into the identity of fossil remains and the natural history of ancient creatures.

    Did Neanderthals Display Symbolism?

    Does the co-occurrence of Neanderthal remains and symbolic artifacts in layer X provide evidence for Neanderthal behavior on par with modern humans? It can, but this conclusion has to align with everything else we know about Neanderthal biology and behavior—and it doesn’t.

    For example, previous work by other archaeologists at the Grotte du Renne has demonstrated that the layers in this cave have been mixed. It appears as if past occupants dug into the cave floor, turning over the cave layers. This activity means that the association between Neanderthal remains and symbolic artifacts could merely be coincidental.

    In the face of this challenge, paleoanthropologists could argue that the 37,000–39,000-year-old date of the remains in layer X (determined in the latest study)—which matches the age of the symbolic artifacts—indicates that mixing didn’t impact layer X. Yet within the past few years, paleoanthropologists have shown that carbon-14 dating of Neanderthal remains has been plagued by carbon-14 contaminants, which renders their measured ages younger than they actually are. Improved methodology (designed to remove these contaminants) places Neanderthal extinction around 45,000+ years bp. This well-known contamination issue raises questions about the dating of the Grotte du Renne specimens, leaving open the real possibility that the Neanderthal remains are much older than 38,000 years in age. If so, it makes it likely that mixing of the cave layers did, indeed, occur.

    Apart from the mixing of the Grotte du Renne cave layers and questions about the dating of the Neanderthal remains in layer X, the most significant reason for skepticism about claims regarding Neanderthals’ symbolic capabilities centers around what we have learned about the anatomy and physiology of this hominid’s brain.

    Collectively, these observations indicate that Neanderthals were cognitively inferior to modern humans. It is hard to square these biological differences with claims that Neanderthals displayed symbolism.

    It is true: Neanderthals had a brain size comparable to modern humans (maybe even slightly larger), but as I point out in Who Was Adam?, the body mass of Neanderthals was larger than modern humans. Anthropologists think that the ratio of brain size to body mass is a better indicator of intelligence than brain size alone. This ratio is called the encephalization quotient (EQ). The EQ of modern humans is greater than that of Neanderthals, indicating that these hominids were cognitively inferior to modern humans.

    More importantly, the brain structures of modern human and Neanderthals differ. As discussed in Who Was Adam?, Neanderthals possessed an underdeveloped parietal lobe compared to modern humans. This part of the brain plays a role in processing information that supports language and mathematical reasoning. Also, Neanderthals devoted a greater region of their brain to vision and body control than modern humans. This would have left a smaller portion of the brain available for advanced cognition. Paleoanthropologists have determined that blood flow to Neanderthal brains was significantly lower compared to modern humans, implying that these hominids inherently lacked the capacity to support the same high level of interneuronal connectivity and synaptic activity as modern humans.

    As discussed in Who Was Adam?, comparisons of modern human and Neanderthal genomes also reveal differences in genes involved in neuronal development. This result helps explain the morphological differences between modern human and Neanderthal brains.

    I also point out that studies of Neanderthal dental microanatomy reveal that these creatures had a rapid, practically nonexistent adolescence. This rapid maturation leaves little time for brain development to occur after birth like it does in modern humans.

    Collectively, these observations indicate that Neanderthals were cognitively inferior to modern humans. It is hard to square these biological differences with claims that Neanderthals displayed symbolism.

    Finally, it is worth noting that every previous claim for Neanderthal symbolism from the archaeological record has failed to withstand scientific scrutiny.2 It is unclear if Neanderthals buried their dead, and if they did, these burials most certainly were not ritualistic. Claims of Neanderthal music and art haven’t panned out, and there is no concrete evidence that Neanderthals had language capacity.

    Take it from someone who has experience concocting stories, the claim that Neanderthals displayed symbolism doesn’t hang together. Anthropologists who claim otherwise should be sent to detention during their lunch hour.

    What if the association between Neanderthal remains and symbolic artifacts proves true? There are other ways to explain their co-occurrence. Because Neanderthals and modern humans coexisted for a brief period of time in Europe, it could be that Neanderthals “appropriated” modern human artifacts and carried them to their cave sites. Given everything we know about Neanderthal brain anatomy, this is a much better story than one that has Neanderthals possessing symbolic capabilities.

    Resources
    Who Was Adam? by Fazale Rana with Hugh Ross (book)
    Paleoanthropologists Mixed Up about Neanderthal Behavior” by Fazale Rana (article)
    The Latest on Neanderthal Extinctions” by Fazale Rana (article)
    Did Neanderthals Make Art?” by Fazale Rana (article)
    Did Neanderthals Bury Their Dead with Flowers?” by Fazale Rana (article)
    Do Neanderthal Cave Structures Challenge Human Exceptionalism?” by Fazale Rana (article)
    Neanderthal Brains Make Them Unlikely Social Networkers” by Fazale Rana (article)
    Blood Flow to Brain Contributes to Human Exceptionalism” by Fazale Rana (article)
    Human, Neanderthal Brains Only Differ after Birth” by Fazale Rana (podcast)

    Endnotes
    1. Frido Welker et al., “Palaeoproteomic Evidence Identifies Archaic Hominins Associated with the Châtelperronian at the Grotte du Renne,” Proceedings of the National Academy of Sciences, USA, published electronically September 16, 2016, doi:10.1073/pnas.1605834113.
    2. For more details, see the articles listed in the resource section of this piece and the expanded and updated edition of Who Was Adam?: A Creation Model Approach to the Origin of Humanity.
  • Blood Flow to Brain Contributes to Human Exceptionalism

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Sep 21, 2016

    Are human beings exceptional? Are we unique, as the Bible teaches?

    Recent work by paleoanthropologists from Australia adds to the mounting scientific evidence for human exceptionalism. These scientists demonstrate that modern humans have an unusually high rate of blood flow to our brains, compared to other primates, including the hominids represented in the fossil record.1 They argue that the increased blood flow to the human brain reflects an unusually high level of: (1) neuron-neuron connectivity; and (2) synaptic activity. Ultimately, these enhanced capabilities support the uniquely advanced cognitive capacity displayed by modern humans. To put it differently, the increased blood flow to the modern human brain helps account for the cognitive differences between humans and the other hominids, including Neanderthals.

    This research helps support a key prediction of RTB’s human origins model (derived from the biblical text) by demonstrating a fundamental difference between humans and Neanderthals.

    Measuring Blood Flow to Hominid Brains

    To establish the relative blood flow to the brains of modern humans and hominids, the researchers measured the radius of the opening of two holes at the base of the skull that serve as the entryway for the internal carotid arteries. These blood vessels accommodate about 85 percent of the blood flow to the human brain. These arteries also give rise to the middle cerebral arteries (which supply the lateral portions of the frontal, parietal, and temporal lobes) and the anterior cerebral arteries (which supply the medial parts of the frontal, and parietal lobes).

     

    blog__inline--blood-flow-to-brain-contributes-to-human-exceptionalism-1

    Image: Internal Carotid Artery. Credit: Wikipedia

    These holes in the skull exclusively provide the conduits for the internal carotid arteries. No accompanying nerves or veins pass through these openings. Blood flow and blood pressure controls the radius and the wall thickness of the arteries, making the size of these openings a reasonable proxy for blood flow to the brain.

    Performing measurements only for complete and undamaged skull openings, the researchers determined the radius of the carotid openings for 34 hominid specimens, representing 12 species, including:

    • africanus (8 specimens)
    • afarensis (3 specimens)
    • boisei (1 specimen)
    • habilis (1 specimen)
    • naledi (1 specimen)
    • rudolfensis (1 specimen)
    • georgicus (1 specimen)
    • erectus (5 specimens)
    • heidelbergensis (2 specimens)
    • neanderthalensis (5 specimens)
    • floresiensis (1 specimen)
    • Archaic sapiens (5 specimens)

    Brain Blood Flow in Hominids

    In lower primates, neuron numbers increase with brain mass in a linear manner (because neurons occupy a constant volume). Measurements made in a previous study for 34 haplorhine primates saw brain blood flow scaling with brain volume.

    But the researchers observed something different for the hominids. While the blood flow to the brain scaled with increases in brain volume for the Australopithecines and early Homo species, a different pattern was observed for H. erectus, H. heidelbergensis, and Neanderthals. Increases in cerebral blood grew at a faster pace than expected based on increases in brain size.

    For modern humans, the increase in cerebral blood flow maxes out, even departing further from the trend line observed for the late appearing Homo species. To put it another way, modern humans (H. sapiens sapiens) stand as an outlier, with an unusually high cerebral blood flow, even compared to Neanderthals.

    Differences in Brain Blood Flow between Humans and Neanderthals

    The primate brain possesses an extremely high aerobic demand, requiring prodigious amounts of oxygen. For modern humans, the brain is responsible for 25 percent of our resting metabolic activity. The brain needs a constant supply of oxygen and nutrients (such as glucose). The disproportionate blood flow to the human brain reflects the high level of interneuronal activity and synaptic transmissions between nerve cells.

    Even though Neanderthals had roughly the same brain size as modern humans, the cerebral blood flow to their brain was significantly lower. This observation implies that these hominids inherently lacked the capacity to support the same high level of interneuronal connectivity and synaptic activity as modern humans. This result lines up with a wide range of other findings (detailed in the expanded and updated edition of Who Was Adam?) indicating Neanderthals had limited cognitive capacity compared to modern humans. Collectively, these results justify skepticism regarding claims that these creatures possessed symbolic capability (language, art, music, body ornamentation, etc.).

    Brain Blood Flow and Implications for Human Uniqueness

    This research helps support a key prediction of RTB’s human origins model (derived from the biblical text) by demonstrating a fundamental difference between humans and Neanderthals. Instead of viewing hominids as evolutionary transitional forms, RTB’s biblical model holds that hominids, including Neanderthals, were animals made by God. They possessed intelligence and emotional capacity, but lacked the image of God—a quality associated only with anatomically modern humans (Genesis 1:26–27). Therefore, we expect that Neanderthals would have displayed behavior that is qualitatively different from, and inferior to, that of modern humans. This study provides confirmation of this expectation.

    This study also provides scientific support for the biblical teaching that human beings are uniquely made in God’s image. If human beings truly are image bearers, then we should expect that scientific data would emerge for human exceptionalism, and it has in a way that aligns with the biblical perspective of humanity’s unique cognitive and behavioral capacities.

    Resources
    Who Was Adam?: A Creation Model Approach to the Origin of Humanity by Fazale Rana with Hugh Ross (book)
    Neanderthal Brains Make Them Unlikely Social Networkers” by Fazale Rana (article)
    Did Neanderthals Make Art?” by Fazale Rana (article)
    Did Neanderthals Bury Their Dead with Flowers?” by Fazale Rana (article)
    Do Neanderthal Cave Structures Challenge Human Exceptionalism?” by Fazale Rana (article)
    Human, Neanderthal Brains Only Differ after Birth” by Fazale Rana (podcast)

    Endnotes
    1. Roger Seymour, Vanya Bosiocic, and Edward Snelling, “Fossil Skulls Reveal that Blood Flow Rate to the Brain Increased Faster than Brain Volume during Human Evolution,” Royal Society Open Science 3 (August 2016): 160305, doi:10.1089/rsos.160305.
  • Does the Evolutionary Paradigm Stymie Scientific Advance?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Sep 12, 2016

    A common challenge I often hear is that creationism and intelligent design are showstoppers for science. If we conclude that “God did it,” skeptics complain, “wouldn’t that shut down scientific inquiry?”

    A few years ago, I had a brief email exchange with a prominent origin-of-life researcher who sincerely raised that concern:

    “I would be interested in how you think the creation model approach . . . will lead to scientific advance. Your book Origins of Life clearly showed that science does not have all the answers to how life may have begun, and of course I agree with that conclusion. What this means to me is that we have some beautiful open questions to work on to try to find the answers. But in your book, at the end of each chapter, you typically ended with the creationist answer to open questions: God did it. This is what I meant by stopping the questioning process. If the answer is that God did it, where do we go from there?”

    I responded to this concern elsewhere, but, at this juncture, I would like to point out that the evolutionary paradigm can also shut down scientific inquiry, delaying the discovery of key scientific insights, and often with important biomedical implications.

    The evolutionary paradigm can also shut down scientific inquiry, delaying the discovery of key scientific insights, and often with important biomedical implications.

    This point is powerfully illustrated by the latest work by a team of researchers from Duke University.1 These investigators demonstrated that the highly repetitive satellite DNA associated with centromeres displays function.

    Repetitive DNA in Evolutionary and Creation Models

    From within the evolutionary framework, this discovery was unexpected. Most molecular biologists have long viewed highly repetitive DNA sequences as nonfunctional. In fact, much of the satellite DNA sequences in the human genome (which comprise 10 percent of the genetic makeup of humans) have been ignored by the research community, because of the influence of the evolutionary paradigm. These sequences have long been regarded as the leftover vestiges of an unguided, evolutionary history.

    A press release from Duke University describing this latest work acknowledges this omission: “Even though the sequence of the human genome was declared complete more than a decade ago, it retains several glaring gaps, especially in the repetitive sequences around centromeres.”2

    Sequencing highly repetitive DNA sequences is extremely challenging, to be sure. And this is part of the reason for the gaps in the human genome sequence. But, because of the influence of the evolutionary paradigm, few, if any, biologists thought these repetitive sequences were anything other than junk. Viewing satellite DNA as junk took away any motivation on the part of molecular biologists to “plow ahead” and try to determine these recalcitrant DNA sequences.

    On the other hand, a creation model/intelligent design perspective predicts that nearly all of the DNA sequences found within the human genome would display function—including highly repetitive satellite DNA sequences. And this prediction is satisfied by the latest insights from the Duke research team.

    To be fair, the Duke researchers were working from an evolutionary framework. So, why were they studying satellite DNA, if other life scientists chose to ignore these sequences? The researchers from Duke University were trying to understand the structure-function relationships of centromeres.

    Centromeres

    These chromosomal regions are made up of highly repetitive DNA dubbed alpha satellite DNA and comprise about 5 percent of the human genomes. Centromeres serve as the attachment site for replicated chromosomes during the cell division process.

    blog__inline--does-evolutionary-paradigm-stymie-scientific-advance-1

    Image: 3-D Chromosome Illustration.

    The alpha satellite DNA of centromeres displays several layers of organization that are built upon a 171 base pair (bp) unit called a monomer. In turn, these monomers are repeated numerous times to form higher order repeats (HORs). The size of the HOR is specific for each of the 22 autosomes and 2 sex chromosomes that comprise the human genome. For example, the HOR of chromosome X consists of 12 monomers, while the HOR of chromosome 8 is made up of six monomers. The next level of organization, called HOR arrays, arises from the extensively repeated occurrence of HORs.

    There can be two or more HOR arrays within centromeres. For example, chromosome 17—the subject of the Duke University study—possesses two HOR arrays, dubbed D17Z1 and D17Z1-B.

    Proteins comprising the kinetochore bind to one or the other HOR array on chromosome 17. (The kinetochore protein complex binds to the centromere, serving as an attachment site for the mitotic spindle, which pulls apart the sister chromosomes during cell division.)

    blog__inline--does-evolutionary-paradigm-stymie-scientific-advance-2

    Image: Mitotic Spindle. Credit: Wikimedia Commons

    As it turns out, for 70 percent of people, the centromere assembles at the D17Z1 site of chromosome 17 for both sister chromosomes. For 30 percent, centromere assembly occurs at the D17Z1 site for one of the sister chromosomes and at the D17Z1-B site of the other.

    Variations in the Repetitive DNA of Centromeres

    In an attempt to determine why one site is used for centromere assembly as opposed to the other, the researchers from Duke University discovered sequence and size variations for the monomers used to build the HOR arrays. And this variation plays a key role in dictating the site for centromere assembly. They also discovered that some sequence and size variants display a loss of functional competency. In other words, this variability can cause the chromosome to become unstable and/or the mitotic spindle fails to properly form. The researchers think that these failures may lead to increased risks of cancer, birth defects, and infertility.

    If the instability becomes too great, the centromere will assemble at alternate HOR array sites, explaining why (for 30 percent of the population) centromere assembly occurs at different sites for the sister chromosomes of human chromosome 17.

    Repetitive DNA Displays Function

    This work indicates that repetitive DNA sequences within the human genome do, indeed, possess functional attributes, just as creationists and intelligent design adherents have predicted. And the researchers think that their insight is only the beginning. Beth Sullivan, the senior researcher for the project stated:

    “What we found in this study is probably the tip of the iceberg. There could be all sorts of functional consequences to having variation within the complex, repetitive portion of the genome that we don’t know about yet.”3

    Implications for Evolutionary and Creation Models

    Many regard the shared “junk DNA” sequences in the genomes of humans and the Great Apes as the most compelling evidence for evolution. When the human genome sequence was first reported in the early 2000s, geneticists estimated that at least 95 percent of human DNA sequences are junk.

    Over the last decade, discovery after discovery has demonstrated that many classes of junk DNA display function. In fact, the ENCODE project indicates that a vast proportion of the human genome is functional, not junk.

    Yet, many evolutionary biologists reject the results of the ENCODE project, insisting that this research effort has mistakenly assigned function to many of the human genome DNA sequences. Why are evolutionary biologists skeptical of the ENCODE project results? Because, if these results are valid, then the evolutionary paradigm can’t be correct.

    Recent work by Duke University scientists demonstrates that, in spite of skepticism over the ENCODE project results, researchers continue to discover new functions for junk DNA. It turns out that these repetitive sequences serve a role in the process of cell division, expanding the role of junk DNA beyond regulating gene expression.

    But in spite of these discoveries, many evolutionary biologists doggedly cling to the view that junk DNA must be nonfunctional because of their deep-seated commitment to the evolutionary paradigm. All of this makes me wonder:

    Is the skepticism about the functional utility of junk DNA—fueled by the demands of the evolutionary paradigm—a science stopper?

    Resources

    Who Was Adam?: A Creation Model Approach to the Origin of Humanity by Fazale Rana with Hugh Ross (book)
    Q&A: Is Christianity a Science Showstopper?” by Fazale Rana (article)
    Responding to ENCODE ‘Skeptics‘” by Fazale Rana (article)
    Do Scientists Accept the Results of the ENCODE Project?” by Fazale Rana (article)
    Is Most of Our DNA Garbage?” by Fazale Rana (podcast)

    Endnotes
    1. Megan E Aldrup-MacDonald et al., “Genomic Variation within Alpha Satellite DNA Influences Centromere Location on Human Chromosomes with Metastable Epialleles,” Genome Research, published electronically August 10, 2016, doi:10.1101/gr.206706.116.
    2. Marla Vacek Broadfoot, “Variation in ‘Junk’ DNA Leads to Trouble,” Duke Today (blog), Duke University, August 30, 2016, https://today.duke.edu/2016/08/variation-%E2%80%9Cjunk%E2%80%9D-dna-leads-trouble.
    3. Ibid.
  • Science News Flash: 3.7-Billion-Year-Old Fossils Perplex Origin-of-Life Researchers

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Sep 07, 2016

    Good things can come from bad circumstances.

    This idea is beautifully illustrated by the research efforts of a team of Australian scientists. Climate change has triggered the excessive melting of ice and snow in western Greenland. This loss of snow and ice concerns many people, but, on the other hand, it has been a boon for the scientific community. It has exposed a new outcropping of rocks, giving geologists first-time access to a rare window of the earth’s distant past. As it turns out, these rocks harbor what appears to be the oldest fossils on Earth—stromatolites that date to around 3.7 billion years in age.1

    Billion year old fossils 

    Image: Stromatolites in western Australia

    This latest insight has important implications for understanding the origin of life. In fact, on the day researchers from Australia reported this discovery in scientific literature, it made headlines in news outlets around the world.2

    Evidence for Early Life on Earth

    As Hugh Ross and I discuss in Origins of Life, geochemists have unearthed a number of chemical markers in the Isua Supracrustal Belt (ISB) of western Greenland that strongly hint at microbial life on Earth between 3.7 and 3.8 billion years ago. But origin-of-life researchers debate the bio-authenticity of these geochemical signatures, because a number of potential abiotic processes can produce similar geochemical profiles.

    Most scientists doubted that fossils would ever be unearthed in the Isua rock formations because these outcrops have undergone extensive metamorphosis, experiencing high temperatures and pressures—conditions that would destroy fossils. But these newly exposed formations contain regions that have experienced only limited metamorphosis, making it possible for fossils to survive.

    Careful microscopic and chemical characterization of the Isua stromatolites affirms their biogenecity. These analyses also indicate that they formed in shallow water marine environments.

    These recently discovered stromatolites (and the previously detected geochemical life signatures in the Isua formations) indicate that a complex and diverse ecology of microorganisms existed on Earth as far back as 3.7 billion years ago.

    Prior to the discovery of 3.7 billion-year-old stromatolites, origin-of-life researchers widely agreed that microbial life existed on Earth around 3.4–3.5 billion years ago, based on the recovery of stromatolites, microbial mats, microfossils, and geochemical signatures in rock formations found in western Australia. Many origin-of-life researchers have expressed amazement that complex microbial ecologies were present on Earth as early as 3.4 billion years ago. For example, paleontologist J. William Schopf marveled:

    “No one had foreseen that the beginning of life occurred so astonishingly early.”3

    The researchers who recovered and analyzed the Isua stromatolites expressed similar surprise:

    “The complexity and setting of the Isua stromatolites points to sophistication in life systems at 3,700 million years ago, similar to that displayed by 3,480–3,400 million-year-old Pilbara stromatolites.”4

    From a naturalistic perspective, the only way for these researchers to make sense of this discovery is to conclude that life must have originated prior to 4 billion years ago. They state: “This implies that by ~3,700 million years ago life already had a considerable prehistory, and supports model organism chronology that life arose during the Hadean (>4,000 million years ago).”5

    Implications for Evolutionary Models

    However, the researchers’ explanation for the appearance of a complex, diverse microbial ecosystem at 3.7 billion years ago is problematic, when the natural history of early Earth is considered.

    Traditionally, planetary scientists have viewed the early Earth as hot and molten, from the time of its formation (4.5 billion years ago) until ~3.8 billion years ago. This era of Earth’s history is called the Hadean. Accordingly, oceans were not present on early Earth until around 3.8 billion years ago. They believe a number of factors contributed to the hellish environment of our early planet, chief of which were the large impactors striking the earth’s surface. Some of these impact events would have been so energetic that they would have volatilized any liquid water on the planet’s surface and rendered the surface and subsurface as a molten state. In light of this scenario, it would be impossible for life to originate much earlier than 3.8 billion years ago. To put it another way, if the traditional understanding of early Earth history is correct, then it looks as if complex microbial ecologies appeared on Earth suddenly—within a geological instant. It is impossible to fathom how the explosive appearance of early life could happen via evolutionary mechanisms.

    More recently, a number of planetary scientists have proposed that early Earth only remained molten for the first 200–300 million years of its history. After which time, oceans became permanent (or maybe semi-permanent) features on the planet’s surface. The basis for this view has been the discovery of zircon crystals that date between 4.2–4.4 billion years ago. Geochemical signatures within these crystals are consistent with their formation in an aqueous setting, implying that oceans were present on Earth prior to 3.8 billion years ago.

    But this revised scenario doesn’t help the evolutionary approach to life’s origin. Around 3.8 billion years ago, a gravitational perturbation in the early solar system sent asteroids towards Earth. Some estimates have the earth experiencing over 17,000 impact events during this time. This event, called the late heavy bombardment (LHB), was originally regarded as a sterilization event. If so, then any life present on Earth prior to the LHB would have been obliterated. That being the case, again, it appears as if complex microbial ecologies appeared on Earth suddenly, within a geological instant.

    Recently, some planetary scientists have challenged the notion that the LHB was a sterilization event. They argue that life on the planet’s surface would have been destroyed, but life in some environments, such as hydrothermal vents, could have survived. In other words, there would have been refugiums on Earth that served as “safe houses” for life, ushering it through the LHB.

    Yet the latest discovery by the Australian scientists doesn’t fit this scenario. The Isua stromatolites formed at the earth’s surface in a shallow water environment. In fact, the research team generated data that effectively ruled out stromatolite formation near hydrothermal vents. But if the refugium model has validity, the Isua fossils should have formed in a high-temperature milieu.

    Finally, pushing life’s origin back to more than 4 billion years ago doesn’t solve the problem of a sudden origin-of-life—it merely displaces it to another window of time in Earth’s history. Origin-of-life researchers have geochemical evidence suggesting that life was present on Earth between 4.2–4.4 billion years ago. Given that the earth was molten for the first 200–300 million years of its existence (minimally), that doesn’t leave much time for life to originate.

    No matter the scenario, a naturalistic, evolutionary approach to the origin-of-life can’t seem to accommodate the sudden appearance of life on Earth. On the other hand, if a Creator brought life into being, this is precisely the mode and tempo expected for life’s appearance on Earth.

    Implications for Creation Models

    While the discovery of 3.7 billion-year-old stromatolites confounds evolutionary explanations for life’s origins, it affirms RTB’s origin-of-life model. This model is derived from the biblical creation accounts and make two key and germane predictions: (1) life should appear on Earth soon after the planet’s formation; and (2) first life should possess intrinsic complexity. And both of these predictions are satisfied by this latest advance.

    Resources
    Origins of Life: Biblical and Evolutionary Models Face Off by Fazale Rana and Hugh Ross (book)
    Creating Life in the Lab: How New Discoveries in Synthetic Biology Make a Case for the Creator by Fazale Rana (book)
    Life May Have Begun 300 Million Years Earlier Than We Thought” by Fazale Rana (podcast)
    Early Life Was More Complex Than We Thought” by Fazale Rana (article)
    When Did Life First Appear on Earth?” by Fazale Rana (article)
    Insight into the Late Heavy Bombardment and RTB’s Creation Model” by Fazale Rana (article)
    Origin-of-Life Predictions Face Off: Evolution vs. Biblical Creation” by Fazale Rana (article)

    Endnotes
    1. Allen P. Nutman et al., “Rapid Emergence of Life Shown by Discovery of 3,700-Million-Year-Old Microbial Structures,” Nature, published electronically August 31, 2016, doi:10.1038/nature19355.
    2. For a detailed discussion of this discovery and its implications for the creation/evolution controversy, listen to “Fossils Indicate Early Life Was Metabolically Complex and Diverse,” Apologia (Ex Libris), podcast audio, August 31, 2016, https://www.reasons.org/podcasts/apologia-premium/fossils-indicate-early-life-was-metabolically-complex-and-diverse.
    3. J. William Schopf, Cradle of Life: The Discovery of Earth’s Earliest Fossils (Princeton, NJ: Princeton University Press, 1999), 3.
    4. Allen P. Nutman, “Rapid Emergence of Life.”
    5. Ibid.
  • Have Origin-of-Life Researchers Found the RNA World "Money Train"?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Aug 31, 2016

    As I write this blog post, amateur treasure hunters in Poland are trying to determine if a local legend is true. According to the lore, during the end of World War II, as the Germans escaped the advancing Soviet army, a train loaded with $200 million in gold, silver, and valuable art disappeared in a complex series of secret tunnels beneath a castle in the Owl Mountains. The treasure hunters claim they have evidence for the location of the buried train and now local authorities are excavating three sites of potential interest. But skepticism abounds. It’s not clear if the legend has any basis in reality. The treasure hunters and local officials may be looking for a treasure that may never have existed.

    Over the last several decades, origin-of-life researchers have been on a quest for their own version of a “money train”: a self-replicating ribozyme. If they can find such a molecule—which may not have ever existed—they will go a long way toward validating one of the most prominent origin-of-life models: the RNA world hypothesis. Recent work by scientists from the Scripps Institute adds to the hope that a self-replicating ribozyme may one day be discovered.1 But careful assessment of their work indicates that their hope may not be based in reality.

    The RNA World Hypothesis

    Many origin-of-life investigators think that RNA predated both DNA and proteins as the premier replicator and information-harboring molecule. Accordingly, RNA operated as a self-replicator that catalyzed its own synthesis. The RNA world hypothesis supposes that, over time, numerous RNA molecules representing a wide-range of catalytic activity emerged. At this point in life’s history, biochemistry centered exclusively on RNA. With time, proteins (and eventually DNA) joined RNA in the cell’s arsenal. During the transition to the contemporary DNA-protein world, RNA’s original function became partitioned between proteins and DNA, and RNA assumed its current intermediary role. RNA ancestral molecules presumably disappeared without leaving a trace of their primordial existence.

    In the mid-1980s, the discovery of RNA molecules with enzymatic activity (called ribozymes) propelled the RNA world hypothesis to prominence.

    Since then, several scientific teams working in the laboratory have produced a number of ribozymes with a range of biological activity using a technique called in vitro evolution. For many origin-of-life researchers, this work adds more credibility to the RNA world scenario. In principle, it demonstrates that life centered on RNA biochemistry is conceivable.

    The Quest for a Self-Replicating RNA

    The real “money train” for the RNA world is a self-replicating ribozyme, but researchers have made limited progress toward discovering this type of ribozyme. For example, they have produced a variety of ribozymes that (1) assist in the synthesis of ribonucleotides; (2) join two RNA chains together (in a process called ligation); and (3) add ribonucleotide subunits to the end of an RNA molecule, extending the chain. All of these activities are necessary for replication of RNA molecules, yet, to date, biochemists have been unable to make RNA with genuine self-replicating capability.

    The latest work by scientists from The Scripps Research Institute (TSRI) adds to these accomplishments, moving origin-of-life researchers closer to a self-replicating RNA. But the train still hasn’t arrived at the station.

    The researchers from TSRI extended the work of earlier studies, using in vitro evolution to modify a ribozyme dubbed the class I RNA polymerase ribozyme. This molecule—initially generated by researchers in the 1990s—can join together some RNA molecules once they bind to a template to produce larger RNA molecules. Later, researchers modified the original ribozyme so that it could use a template to form RNA chains over 100 nucleotides in length. Unfortunately, the modified version of the class I RNA polymerase ribozyme is quite finicky. While it can only transcribe RNA with certain nucleotide sequences and cannot transcribe RNA molecules with complex three-dimensional structures.

    TSRI scientists randomly mutated the RNA sequence of the modified version of the class I RNA polymerase to generate a population of 100 trillion molecules. From this population, they selected those ribozymes that could transcribe two different RNA molecules with a complex three-dimensional structure. Once they identified the ribozymes with the desired properties, they repeated the process, mutating the newly identified ribozymes to produce a new population of molecules. After 24 rounds, they had successfully evolved a ribozyme (they called the 24-3 ribozyme) that can copy RNA molecules with complex three-dimensional structures and, in turn, make copies of RNA molecules it had already copied. That is, the 24-3 polymerase can amplify specific RNA molecules 10,000 fold.

    While this is an important advance for the RNA world hypothesis, the 24-3 polymerase can’t copy itself, a necessary requirement for self-replication.

    Evolution or Intelligent Design?

    This work has important implications for the creation-evolution debate. Origin-of-life researchers and evolutionary biologists count these types of studies as support for the RNA world hypothesis. More broadly, they point to these types of studies as evidence that evolutionary processes can generate information-rich molecules from random sequences and transform existing biomolecules into ones with new or improved function.

    As a Christian apologist, I have to acknowledge that these scientists have a point. In principle, evolutionary mechanisms can generate bioinformation.2 But, I would argue that studies in in vitro evolution have failed to provide any evidence that evolutionary processes can generate information under the conditions of early Earth.

    As I discuss in Creating Life in the Lab, the process of in vitro evolution relies on a carefully developed experimental design and researcher intervention. The protocol begins with a large pool of RNA molecules with random nucleotide sequences, and hence, random structures. From this pool, researchers select (through the experiment’s design) RNA molecules with a predetermined set of chemical properties. These selected RNA molecules are recovered and their number amplified by the enzyme reverse transcriptase and the polymerase chain reaction (PCR). PCR also employs an enzyme, a DNA polymerase. The new RNA sequence is then randomly altered to generate a new pool of RNA molecules using another enzyme called T7 RNA polymerase, and the process is repeated again and again until RNA molecules with the desired chemical properties emerge. Production of the RNA self-replicators also required researchers to modify the structure of ribozymes generated by in vitro evolution using rational design principles to improve upon the ribozymes’ function.

    The “evolution” of RNA molecules in the laboratory is a carefully orchestrated process devised and managed by intelligent agents. Its success hinges on thoughtful experimental design. Researchers are manipulating the evolutionary process, guiding it to the desired outcome. It must be noted that essential to the success of in vitro evolution studies are the enzymes (protein molecules with a complex, fine-tuned structure), reverse transcriptase, T7 RNA polymerase, and DNA polymerase—molecules that would never have existed in an RNA world. It stretches the bounds of credulity to think that this process, or one like it, could have occurred naturally on early Earth.

    As thrilling as this most recent achievement is, origin-of-life researchers have fallen short of demonstrating that information-rich RNA molecules can evolve under the uncontrolled conditions of early Earth.

    It is ironic: The very experiments designed to bolster an evolutionary explanation for the origin of life provide powerful support for the role intelligent agency must play in the genesis of life.

    Resources
    Creating Life in the Lab: How New Discoveries in Synthetic Biology Make a Case for the Creator by Fazale Rana (book)
    Too Good to be True: Evolution and the Origin of Bioinformation” by Fazale Rana (article)
    Intelligent Design: The Right Conclusion, but the Wrong Reasons” by Fazale Rana (article)
    Does New Approach Solve Origin-of-Life Problem?” by Fazale Rana (article)

    Endnotes
    1. David P. Horning and Gerald F. Joyce, “Amplification of RNA by an RNA Polymerase Ribozyme,” Proceedings of the National Academy of Sciences, USA, published electronically August 15, 2016, doi:10.1073/pnas.1610103113.
    2. Some people might find it surprising that I would acknowledge this point, because many Christian apologists assert that evolutionary mechanisms cannot generate information. In my view, that claim is patently false, as work in in vitro evolution has demonstrated, time and time again.
  • Piltdown Man: The Fact and Fantasy of the Hominid Fossil Record

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Aug 24, 2016

    In high school and college, I played my fair share of practical jokes. While a few of the victims of my hoaxes appreciated my sense of humor, most were “not amused.” (To quote my high school English teacher Mrs. Hodges who, in turn, was quoting Queen Victoria: “Mr. Rana, we are not amused.”)

    Hoaxes aren’t just frowned upon in high school. They are really frowned upon in science. They undermine the integrity of the scientific process. And because of the damage they can cause, scientific hoaxes have been known to end careers.

    Perhaps one of the most significant scientific hoaxes ever took place around the turn of the last century, when Piltdown man fossils were discovered. These fossils—which turned out to be forgeries—were touted as the missing link in human evolution and misdirected paleoanthropology for nearly 40 years. Though many suspects have been identified, nobody knew who perpetrated this hoax—until now, thanks to the efforts of a multidisciplinary research team from the UK.1

    Piltdown Man

    In 1912, Charles Dawson and Arthur Smith Woodward reported on fossils recovered from ancient graves near Sussex, England. Pieces of a human-like cranium, a partial ape-like jaw, and a few worn-down molars were interpreted to come from an individual hominid (deemed Eoanthropus dawsoni). The fragments displayed the very features that evolutionary biologists expected to see in the missing link.

    Dawson and Woodward reported that their specimen was associated with other ancient mammal fossils, so they dated their find at about 500,000 years old.

    Piltdown man’s status as humanity’s ancestor gained further credence with Dawson’s 1915 report of a second specimen recovered near Sheffield Park (dubbed Piltdown man II).

    Exposing the Fraud

    However, after Raymond Dart discovered Australopithecus in 1924, some scientists began to think Dart’s newly recognized hominid—not Piltdown man—was the one that led to modern humans. Scientists further questioned Piltdown man’s importance as a transitional form in the 1930s when paleoanthropologists discovered and confirmed Pithecanthropus erectus and Sinanthropus pekinensis as ancient hominids. For some paleoanthropologists, Piltdown man was relegated to a mere evolutionary side branch. But still, Piltdown man cast a shadow over paleoanthropology, causing some scientists to question the significance of Dart’s finds and the hominids unearthed in China.

    The legendary Piltdown man forgery went unrecognized for nearly 40 years until a team of scientists exposed it as a fraud in 1953. Better dating of the site of Piltdown man’s discovery and careful chemical and morphological analysis of the fossil specimens ultimately exposed what Alexander Kohn (one-time editor of the Journal of Irreproducible Results) called “the most elaborate scientific hoax ever perpetuated.”2 The fossils were actually carefully doctored modern remains stained with a dye to make them appear old. The cranium pieces were human. The jaw bone fragment came from an orangutan. The teeth were carefully filed to fit the mandible and make them appear more human-like.

    So who is responsible for the Piltdown man forgery? Science historians have debated the perpetrator’s identity and the motivation behind his or her actions. Thanks to the work of the multidisciplinary team, we are closer to knowing who the perpetrator was. These scientists applied state-of-the-art analytical techniques to the Piltdown man fossils to gain better insight into the nature of the forgery. Using DNA analysis, they determined that the orangutan jaw bone and molars from Piltdown man and Piltdown man II specimens came from the same creature that lived in Borneo.

    Three-dimensional x-ray imaging indicated that the skull bones and teeth were all doctored in the same way. The same dental putty was used to fill bones and affix teeth to the mandible for Piltdown man I and II specimens. These results all point to the work of a single forger.

    Given the circumstances surrounding Piltdown man’s “discovery,” the evidence strongly points to Charles Dawson as the culprit. As the authors of the study point out:

    “Over the years, at least 20 others have been accused of being the perpetrator, but in many cases, the allegation also includes Dawson as co-conspirator. This is largely because the story originated with him, he brought the first specimens to Dr. Arthur Smith Woodward, Keeper of Geology at the British Museum (Natural History) in 1912, nothing was ever found at the site when Dawson was not there, he is the only known person directly associated with the supposed finds at the second Piltdown site, the exact whereabouts of which he never revealed, and no further significant fossils, mammal or human, were discovered in the localities after his death in 1916.”3

    As impressive as this work is: Why spend so much effort to study fossil forgery? The rationale is two-fold. First, this study demonstrates the value of emerging techniques to shed light on age-old questions in paleoanthropology. Second, this project focuses renewed attention on the Piltdown man forgery—100 years after Dawson’s death—serving as a reminder of how powerful biases can influence interpretations of the fossil record.

    Science historians have long discussed why the scientific community so readily accepted Piltdown man as authentic, and why it took so long to recognize the discovery as a forgery, since (at least in retrospect) many indicators along this line were quite evident.

    These complex questions have complex answers. In part, the ready acceptance of Piltdown man stemmed from the eagerness to find the “missing link” to support Darwin’s model for human evolution with evidence from the fossil record. Piltdown man exactly fit the scientific community’s preconceived ideas as to what the transitional intermediate between humans and apes must look like. According to Kohn:

    “Scientists, contrary to lay belief, do not work by collecting only ‘hard’ facts and fitting together information based on them. Scientific investigation is also motivated by pursuit of recognition and fame, by hope and by prejudice. Dubious evidence is strengthened by strong hope: anomalies are fitted into a coherent picture with the help of cultural bias.”4

    To put it another way: Scientists are human, and from time to time their fallibility or bias can influence the scientific process. The scientists who took part in this study agree. Based on their investigation into the Piltdown man forgery, they acknowledge that:

    “It has opened our eyes to the scientific rigour required to avoid being deceived in the same manner as so many scientists were between 1912 and 1917. As scientists, we must not be led by preconceived ideas in the evaluation of new discoveries.”5

    I fully agree with the authors, but as a skeptic of the evolutionary paradigm I have to ask: Has a different type of bias colored the interpretation of hominid fossil record? Many biologists claim that human evolution is a fact. In light of this commitment, anthropologists interpret the hominid fossil record from a preconceived evolutionary perspective, in spite of the scientific challenges to human evolution that arise from the hominid finds. In my experience, few, if any, anthropologists are open to the possibility that evolutionary mechanisms alone may be insufficient to account for humanity’s origins, regardless of the evidence at hand.

    And, in my view, this bias has misdirected attempts to understand humanity’s origins for the last 150 years.

    Resources
    Q&A: Are There Transitional Intermediates in the Fossil Record?” by Fazale Rana (Article)
    The Amazing Disappearing Hominid!” by Fazale Rana (Article)
    A Key Transitional Form in Human Evolution May Not Have Existed” by Fazale Rana (Article)
    The Unreliability of Hominid Phylogenetic Analysis Challenges the Human Evolutionary Paradigm” by Fazale Rana (Article)
    Who Was Adam? by Fazale Rana with Hugh Ross (Book)

    Endnotes
    1. Isabelle De Groote et al., “New Genetic and Morphological Evidence Suggests a Single Hoaxer Created ‘Piltdown Man,’” Royal Society Open Science 3 (August 2016): 160328, doi:10.1098/rsos.160328.
    2. Alexander Kohn, False Prophets: Fraud and Error in Science and Medicine, rev. ed. (Oxford, UK: Basil Blackwell, 1988), 133.
    3. De Groote, “New Genetic and Morphological Evidence.”
    4. Kohn, False Prophets, 140.
    5. De Groote, “New Genetic and Morphological Evidence.”
  • DNA: Designed for Flexibility

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Aug 17, 2016

    Over the years I’ve learned that flexibility is key to a happy and successful life. If you are too rigid, it can create problems for you and others and rob you of joy.

    Recently, a team of collaborators from Duke University and several universities in the US discovered that DNA displays unexpected structural flexibility. As it turns out, this property appears to be key to life.1 In contrast, the researchers showed that RNA (DNA’s biochemical cousin) is extremely rigid, highlighting another one of DNA’s unique structural properties that make it ideal as the cell’s information storage system.

    To appreciate DNA’s uniquely optimal properties, a review of this important biomolecule’s structure is in order.

    DNA

    DNA consists of two chain-like molecules (polynucleotides) that twist around each other to form the DNA double helix. The cell’s machinery forms polynucleotide chains by linking together four different sub-unit molecules called nucleotides. DNA is built from the nucleotides: adenosine, guanosine, cytidine, and thymine, famously abbreviated A, G, C, and T, respectively.

    In turn, the nucleotide molecules that make up the strands of DNA are complex molecules, consisting of both a phosphate moiety, and a nucleobase (either adenine, guanine, cytosine, or thymine) joined to a 5-carbon sugar (deoxyribose). (In RNA, the five-carbon sugar ribose replaces deoxyribose.)

    blog__inline--dna-designed-for-flexibility-1 

    Image 1: Nucleotide Structure

    The backbone of the DNA strand is formed when the cell’s machinery repeatedly links the phosphate group of one nucleotide to the deoxyribose unit of another nucleotide. The nucleobases extend as side chains from the backbone of the DNA molecule and serve as interaction points (like ladder rungs) when the two DNA strands align and twist to form the double helix.

    blog__inline--dna-designed-for-flexibility-2 

    Image 2: The DNA Backbone

    When the two DNA strands align, the adenine (A) side chains of one strand always pair with thymine (T) side chains from the other strand. Likewise, the guanine (G) side chains from one DNA strand always pair with cytosine (C) side chains from the other strand.

    When the side chains pair, they form cross bridges between the two DNA strands. The length of the A-T and GC cross bridges is nearly identical. Adenine and guanine are both composed of two rings and thymine (uracil) and cytosine are composed of one ring. Each cross bridge consists of three rings.

    When A pairs with T, two hydrogen bonds mediate the interaction between these two nucleobases. Three hydrogen bonds accommodate the interaction between G and C. The specificity of the hydrogen bonding interactions accounts for the A-T and G-C base-pairing rules.

    blog__inline--dna-designed-for-flexibility-3 

    Image 3: Watson-Crick Base Pairs

    Watson-Crick and Hoogsteen Base Pairing

    In DNA (and in RNA double helixes), the base pairing interactions occur at precise locations between the A and T nucleobases and the G and C nucleobases, respectively. Biochemists refer to these exacting interactions as Watson-Crick base pairing. However, in 1959—six years after Francis Crick and James Watson published their structure for DNA—a biochemist named Karst Hoogsteen discovered another way—albeit, rare—that the A and T nucleobases and the G and C nucleobases pair, called Hoogsteen base pairing.

    Hoogsteen base pairing results when the nucleobase attached to the sugar rotates by 180°. Because of the dynamics of the DNA molecule, this nucleobase rotation occurs occasionally, converting a Watson-Crick base pair into a Hoogsteen base pair. However, the same dynamics will eventually revert the Hoogsteen base pair to a Watson-Crick pairing. Hoogsteen base pairs aren’t preferred because they cause a distortion in the DNA double helix. For a “naked” piece of DNA in a test tube, at any point in time, about 1 percent of the base pairs are of the Hoogsteen variety.

    blog__inline--dna-designed-for-flexibility-4 

    Image 4: Watson-Crick and Hoogsteen Base Pairs
    Image Credit: Wikimedia Commons

    While rare in naked DNA, biochemists have recently discovered that the Hoogsteen configuration occurs frequently when: 1) proteins bind to DNA; 2) DNA is methylated; and 3) DNA is damaged. Biochemists now think that Hoogsteen base pairing is important to maintain the stability of the DNA double helix, ensuring the integrity of the information stored in the DNA molecule.

    According to Hashim Al-Hashimi, “There is an amazing complexity built into these simple beautiful structures, whole new layers or dimensions that we have been blinded to because we didn’t have the tools to see them, until now.”2

    It looks like the capacity to form Hoogsteen base pairs is a unique property of DNA. Al-Hashimi and his team failed to detect any evidence for Hoogsteen base pairs in double helixes made up of two strands of RNA. When they chemically attached a methyl group to the nucleobases of RNA to block the formation of Watson-Crick base pairs and force Hoogsteen base pairing, they discovered that the RNA double helix fell apart. Unlike the DNA double—which is flexible—the RNA double helix is rigid and cannot tolerate a distortion to its structure. Instead, the RNA strands can only dissociate.

    It turns out that the flexibility of DNA and the rigidity of RNA is explained by the absence of a hydroxyl group in the 2’ position of the deoxyribose sugar of DNA and the presence of the 2’ hydroxyl group on ribose sugar of RNA, respectively. The 2’ position is the only structural difference between the two sugars. The presence or absence of the 2’ hydroxyl group makes all the difference. The deoxyribose ring can more freely adopt alternate conformations (called puckering) than the ribose ring, leading to differences in double helix flexibility.

    blog__inline--dna-designed-for-flexibility-5 

    Image 5: Difference between Deoxyribose and Ribose

    This difference makes DNA ideally suited as an information storage molecule. Because of its ability to form Hoogsteen base pairs, the DNA double helix remains intact, even when the molecule becomes chemically damaged. It also makes it possible for the cell’s machinery to control the expression of the genetic information harbored in DNA through protein binding and DNA methylation.

    It is intriguing that DNA’s closet biochemical analogue lacks this property.

    It appears that DNA has been optimized for data storage and retrieval. This property is critical for DNA’s capacity to store genetic information. DNA harbors the information needed for the cell’s machinery to make proteins. It also houses the genetic information passed on to subsequent generations. If DNA isn’t stable, then the information it harbors will become distorted or lost. This will have disastrous consequences for the cell’s day-to-day operations and make long-term survival of life impossible.

    As I discuss in The Cell’s Design, flexibility is not the only feature of DNA that has been optimized. Other chemical and biochemical features appear to be carefully chosen to ensure its stability; again, a necessary property for a molecule that harbors the genetic information.

    Optimized biochemical systems comprise evidence for biochemical intelligent design. Optimization of an engineered system doesn’t just happen—it results from engineers carefully developing their designs. It requires forethought, planning, and careful attention to detail. In the same way, the optimized features of DNA logically point to the work of a Divine engineer.

    Resources
    DNA Soaks Up Sun’s Rays” by Fazale Rana (Article)
    The Cell’s Design by Fazale Rana (Book)
    The Cell’s Design: The Proper Arrangement of Elements” by Fazale Rana (Podcast)

    Endnotes
    1. Huiqing Zhou et al., “m1A and m1G Disrupt A-RNA Structure through the Intrinsic Instability of Hoogsteen Base Pairs,” Nature Structure and Molecular Biology, published electronically August 1, 2016, doi:10.1038/nsmb.3270.
    2. Duke University, “DNA’s Dynamic Nature Makes It Well-Suited to Serve as the Blueprint of Life,” Science News (blog), ScienceDaily, August 1, 2016, www.sciencedaily.com/releases/2016/08/160801113823.htm.
  • Can Keratin in Feathers Survive for Millions of Years?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Aug 10, 2016

    I don’t like conflict. In fact, I try to avoid it whenever possible. And that’s part of the reason I never wanted to become directly involved in the young-earth/old-earth controversy that takes place within the church.

    Frankly, I find the debate tedious, and a distraction from the real work at hand: helping skeptics and seekers recognize the scientific evidence for God’s existence and Scripture’s reliability.

    Of course, if people ask me age-of-the-earth questions, I am quick to explain why I hold to an old-earth/day-age interpretation for Genesis 1 and what I see as biblical, theological, and scientific issues with a young-earth/calendar day interpretation of the Genesis 1 creation account.

    Soft Tissues in Fossils and the Age of the Earth

    Over the course of the last few years, one question that has come up a lot relates to the discovery of soft tissue remnants in fossils, such as the blood cells and blood vessels remains recovered from a T. rex specimen that age-dates to 68 million years old. Young earth creationists make use of these surprising results to argue that it is impossible for fossils to be millions of years old. They argue that soft tissues shouldn’t survive that long. These materials should readily degrade in a few thousand years. In their view, these finds challenge the reliability of radiometric dating methods used to determine the age of these fossils, and along with it, Earth’s antiquity. Instead, they argue that these breakthrough discoveries provide compelling scientific evidence for a young Earth and support the idea that the fossil record results from a recent global (worldwide) flood.

    Because I’m a biochemist—and an old earth creationist—people frequently ask me how I make sense of the T. rex find and the discovery of other types of soft tissue remnants in the fossil remains of other creatures that age-date to several hundred million years, in some cases.

    Dinosaur Blood and the Age of the Earth

    These queries eventually motivated me to write Dinosaur Blood and the Age of the Earth. And I am glad I did. Aside from the young-earth/old-earth debate, the scientific questions related to soft tissue finds in fossils are captivating.

    The central question of Dinosaur Blood and the Age of the Earth centers around soft tissue durability: If radiometric dating is reliable, then how is it possible for soft tissue remnants to persist for millions of years?

    Recent work by a research team at North Carolina State University (NC State)—headed up by Mary Schweitzer—helps address this question, specifically focusing on beta-keratin fragments recovered from the fossilized feathers and claws of Shuvuuia deserti and Rahonavis ostromi.1

    How Can Keratin Survive in Fossils?

    As I discuss in Dinosaur Blood and the Age of the Earth, some biomolecules (such as keratins) form extremely stable structures that delay their degradation. Keratins have a number of structural features (such as extensive crosslinking) that helps explain why fragments of these proteins could survive for tens of millions of years, under the right conditions.2 But my analysis was theoretical. Even though my assessment was based on sound biochemical principles, it would be nice to have some corroborating experimental evidence to support my claims. (The old saying in science applies: “theories guide, experiments decide.”) And that is precisely what the NC State researchers provide in their recent study.

    Feather Decomposition

    Schweitzer and her team conducted a ten-year experiment to gain insight into the natural degradation processes of feathers (and other biological materials made up of keratins such as skin, claws, beaks, and hair). To do this, they exposed feathers from a Hungarian partridge to a variety of conditions, and then analyzed the samples busing: (1) transmission electron microscopy (TEM) to monitor changes in the fine structure of the feather’s anatomy; and (2) a technique called in situ immunofluorescence to determine if pieces of keratin proteins persisted in the feather remains.

    Of particular interest is the feather samples Schweitzer and her team wrapped in aluminum foil and heated in an oven for 10 years at 630°F—conditions used to sterilize glassware. Many paleontologists consider high heat to be a proxy for deep time.

    Perhaps it is no surprise, when viewed under a microscope, the macroscopic features of feathers treated at high temperatures were completely lost. Instead the only thing visible were shiny black pieces of “charcoal-like” material. Yet, when examined at high magnification with a TEM, the investigators were able to visualize fragments of feather barbs. Using their immunofluorescence technique, the researchers were able to detect clear evidence of keratin fragments in the sample.

    These observations align with my thoughts about keratin’s durability, making it all the more reasonable to think that soft tissue remnants persist in millions-of-years old fossil remains. In fact, when the researchers applied their immunofluorescence to the Shuvuuia deserti samples, once again, they found evidence for keratin fragments in these fossil remains.

    Preservation Mechanisms

    As I point out in Dinosaur Blood and the Age of the Earth, molecular durability alone isn’t sufficient to account for soft tissue survivability. For soft tissue remnants to persist in fossil, the rate of fossilization has to outpace the rate of soft tissue degradation. When that happens, a mineral ‘casing’ will entomb the soft tissue before it completely decomposes, preserving it for paleontologists to later discover. In addition to molecular durability, scientists have identified a number of mechanisms that contribute to both the degradation and preservation of soft tissues during the process of burial and fossilization.

    Along these lines, the NC State scientists speculate on processes that might extend keratin’s survivability in feathers—at least, long enough for mineral entombment to occur. They think one of their observations about the high-heat sample offers a clue. The research team noted that melanosomes (the organelles that harbor pigments, giving feathers their colors) were absent after heating for ten years at 630°F. On this basis, they conclude that paleontologists have made a mistake when they interpret microbodies as melanosomes in fossilized feathers. Instead, they think that the mirobodies derive from microbes.

    This reinterpretation is good news for keratin preservation on two accounts. It is true that microbial activity can destroy soft tissues, but the NC State scientists think it can also help speed up the fossilization process leading to the preservation of keratin remnants. How? Because microbes secrete materials (called exopolymeric substances) that promote deposition of minerals, speeding up the entombment of the soft tissue. Additionally, the NC State researchers think that melanosome degradation may also be important. When these organelles break down, they release their contents (eumelanin) which may function like a fixative, slowing down tissue degradation long enough for the soft tissue to be entombed.

    The NC State study has unearthed fascinating details regarding feather decomposition and provides key insights that help account for the persistence of keratin in fossilized remains of reptiles, birds, and feathered dinosaurs that date to tens of millions of years old.

    Resources
    Structure of Collagen Unravels the Case for a Young Earth” by Fazale Rana (Article)
    Dinosaur Blood and the Age of the Earth by Fazale Rana (Book)

    Endnotes
    1. Alison Moyer, Wenxia Zheng, and Mary Schweitzer, “Keratin Durability Has Implications for the Fossil Record: Results from a 10 Year Feather Degradation Experiment,” PLoS One 11 (July 2016): e0157699, doi:10.1371/journal.pone.0157699.
    2. Fazale Rana, Dinosaur Blood and the Age of the Earth (Covina, CA: RTB Press, 2016), 57–58.
  • The Evolution of the Automobile: Evidence for Intelligent Design

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Aug 03, 2016

    “It’s déjà vu all over again.”

    As the story goes, baseball player and manager Yogi Berra first uttered this famous yogi-ism sitting in the dugout watching Mickey Mantle and Roger Maris hit back-to-back home runs. Something that happened on more than one occasion.

    Yogi Berra’s verbal blunders are legendary. But, perhaps none top the blunder made by biologist Tim Berra. Berra’s blunder didn’t have anything to do with what he said, but with what he wrote in his book Evolution and the Myth of Creationism, published in 1990.

    Berra’s Blunder

    Targeting a nontechnical audience, Berra presented a case for biological evolution and explained why he and so many scientists think evolution is a fact. As part of this project, he described the evidence for human evolution, highlighting the progressive features of the hominid fossil record. Berra argues,

    “If the australopithecines, Homo habilis, and Homo erectus were alive today, and if we could parade them before the world, there could be no doubt about our relatedness to them. It would be like attending an auto show. If you look at a 1953 Corvette and compare it to the latest model, only the most general resemblances are evident, but if you compare a 1953 and a 1954 Corvette, side by side, then a 1954 and 1955 model, and so on, the descent with modification is overwhelmingly obvious. This is what paleontologists do with fossils, and the evidence is so solid and comprehensive that it cannot be denied by reasonable people.”1

    In comparing Corvette models with “transitional intermediates” in the fossil record, Berra made a significant error that has become known among creationists and ID proponents as Berra’s blunder. It almost goes without saying, Berra’s mistake was to use Corvettes—machines designed by automotive engineers—as an analogy for the hominid fossil record, claiming that sequential anatomical changes among the various hominid species reflect the outworking of an unguided evolutionary process in the same way that sequential design changes to Corvettes reflect the evolution of technology. But, as pointed out at that time by several creationists and intelligent design proponents, the Corvette sequence actually tells us something about how intelligent agents sometimes create: namely, designers can attain their goals by progressively modifying existing designs. To put it another way, the chronological appearance of organisms in the fossil record displaying serial changes to their anatomical, physiological, and behavioral features could be explained as the work of a Creator who was successively producing creatures that displayed modifications of an archetypical design. In this sense, the fossil record doesn’t necessarily compel reasonable people to accept biological evolution any more than does the evolution of the American automobile.

    The sequential changes seen in the fossil record just as reasonably reflect the work of a mind as mechanism.

    Déjà Vu Once More

    Recently, researchers from UCLA made the same blunder as Tim Berra—all over again!2 These investigators wanted to understand the principles that influence the tempo and mode for technology development in a society. As a case study, these investigators examined the appearance and disappearance of American car and truck models manufactured between 1896 (when automobiles were first produced) and 2014, using the same approach that paleontologists might use to study the fossil record. Specifically, they monitored the year-by-year diversity of automobile models, paying special attention to the number of new models that were produced (analogous to speciation) each year and the number of discontinued models (analogous to extinction).

    These researchers also explored the factors influencing the diversity of automobile models each year. Particularly, they assessed the effects of competition, and the impact of Gross Domestic Product (GDP) and oil prices.

    Their analysis indicates that the “origination” and “extinction” rates of automobile models displayed highly similar patterns over the course of the last 118 years. In both cases, origination and extinction rates were highest early in the automobile’s history, gradually declining to lower rates over time. The rates of decline dramatically slowed in the 1960s when the Big Three auto manufacturers rose to dominance in the American market place. Since the 1980s, the rate of automobile model extinction has outpaced the appearance rate of new models. However, during this time frame, the lifespan of automobile models has significantly increased.

    The UCLA researchers also discovered that completion has had a much greater influence on automobile diversity than GDP and oil prices.

    Based on these results, the authors of this study argue that when a technology is in its early stages, manufacturers introduce more experimental designs into the marketplace. But because these designs are experimental, they also disappear more rapidly. They maintain that the appearance and disappearance rates slow as dominant designs emerge. When that happens, it becomes too costly to introduce experimental models into the marketplace. Eventually, cost becomes such a significant factor that it causes the life expectancy of designs to persist for longer time periods.

    Based on this study, the UCLA scientists predict that in the near future the number of hybrid and electric car designs will rapidly diversify—a radiation event, of sorts—because these technologies are in their nascent stages.

    The Fossil Record and the Case for Creation

    The UCLA researchers demonstrated that some of the techniques paleontologists use to study the fossil record—and hence, the history of life on Earth—can yield important insights about the way cultures and technologies change and develop. However, as with Berra’s blunder, they treated designed objects as if they were fossils, which, according to the evolutionary paradigm, are produced by unguided, mechanistic processes. The approach the UCLA research team used to study technology development, once again, highlights the fact that the sequential changes seen in the fossil record just as reasonably reflect the work of a mind as mechanism.

    But, it is possible to take the implications of their work one step further. Not only can we argue that the progressive anatomical changes observed in fossilized organisms reflect the Creator’s handiwork, but so do overall patterns in the fossil record. The UCLA study demonstrates that when it comes to technology produced by human designers, the number of design variants and the rate that designs appear and disappear from the marketplace have a rational basis. Though the rationale may be different than what the UCLA researchers discovered for the automobile’s evolution, it becomes all the more reasonable to view changes in biological diversity and origination and extinction rates in the fossil record as reflecting a Creator’s intentional activity.

    In other words, the evidence (the fossil record and homology) that biologists insist provides compelling support for the evolutionary paradigm actually finds ready explanation from a creation model perspective.

    Resources

    Archetype or Ancestor? Sir Richard Owen and the Case for Design” by Fazale Rana (Article)

    Endnotes
    1. Tim Berra, Evolution and the Myth of Creationism (Stanford, CA: Stanford University Press, 1990), 117.
    2. Erik Gjesfjeld et al., “Competition and Extinction Explain the Evolution of Diversity in American Automobiles,” Palgrave Communications 2 (May 2016): 16019, doi:10.1057/palcomms.2016.19.
  • Science News Flash: Are Humans Still Evolving?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Aug 01, 2016

    Are human beings divinely created? Or are we the product of an evolutionary history? Or both?

    Nearly everyone has some interest in human origins. And for that reason, it’s not surprising that discoveries in anthropology frequently garner headlines and serve as fodder for popular science pieces.

    Recently, paleoanthropologist John Hawks from the University of Wisconsin-Madison wrote an excellent piece for the August 2016 edition of The Scientist entitled, “Humans Never Stopped Evolving.” In this article, Hawks discusses a number of recent studies that identify natural selection at work in human beings and presents scientific updates on several well-known examples of evolutionary changes in humans, such as the ability to digest milk sugar and the origin of regional differences (racial diversity).

    In all cases, the underlying implication is: If we observe human evolution happening before our eyes—time and time againthen we have clear-cut evidence that human beings evolved. But is that really the case? Is that the proper conclusion to draw from these scientific observations?

    I would say, no.

    From a creationist perspective, that the ability of humans (and other creatures) to adapt through microevolutionary change is evidence for God’s provision and providence.

    The evolutionary changes described by Hawks are merely examples of microevolutionary changes—variation within a species. In fact, it could be argued from a creationist perspective that the ability of humans (and other creatures) to adapt through microevolutionary change is evidence for God’s provision and providence.

    Hawks’ examples of human evolution fall into the same category as (1) the acquisition of antibiotic resistance by bacteria; (2) the development of pesticide and herbicide resistance by insects and plants; (3) the change in wing color of the peppered moth; and (4) the variation in beak shape by the finches on the Galapagos Islands.

    These common examples of evolutionary changes are often cited as evidence for biological evolution. Microevolutionary changes, however, don’t necessarily extend to support macroevolutionary changes (the creation of biological novelty through undirected evolutionary processes). And there are many reasons—see Who Was Adam?—to be skeptical of evolutionary explanations for the origin of humanity.

    Evidence for human microevolution does not constitute evidence for human evolution.

    Resources
    Evidence That Humans Are Evolving Is Not Evidence for Human Evolution” by Fazale Rana (Article)
    Human Evolution Speeding Up” (Podcast)
    Modern Life’s Pressures May Be Hastening Human Evolution” (Podcast)
    Who Was Adam? by Fazale Rana with Hugh Ross (Book)
    RTB Live! Vol. 15: Exploring the Origin of the Races with Fazale Rana (DVD)

  • Science News Flash: Has the Last Universal Common Ancestor Been Identified?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 28, 2016

    Researchers from Germany made headlines by announcing that they are one step closer to identifying LUCA (the last universal common ancestor)—the single-celled organism that anchors the evolutionary tree of life.1

    Because an organism’s genes reflect its environment, these researchers attempted to partially reconstruct LUCA’s genome. They reasoned that this reconstruction would tell them something about LUCA’s complexity and lifestyle.2 To accomplish this task, the researchers searched 6.1 million protein-coding genes found in archaeal and bacterial genomes for those with a special type of history (that is, they searched for universal, monophyletic genes).

    They identified 355 types of genes that fit their criteria. A few of the genes appear to be involved with essential biochemical operations such as DNA replication, transcription, and translation. On the other hand, most of the 355 genes play highly specialized roles that reflect a thermophilic lifestyle. For example, they discovered an enzyme called reverse gyrase that is only found among microbes that live in high-temperature environments. They also discovered enzymes that are part of a metabolic route called the Wood-Ljungdahl pathway. This pathway uses molecular hydrogen as an electron donor, and carbon dioxide as an electron acceptor. The hydrogen had to come from a geological source. On this basis, the German scientists concluded that LUCA lived in a hydrothermal vent environment, providing a ready source for this life-giving gas.

    The researchers also discovered that this microbe was able to: 1) fix nitrogen from the environment, incorporating this atom into it’s biomolecules; 2) lived in an anaerobic environment (devoid of oxygen); but 3) didn’t seem to have the ability to make amino acids. The investigators think that LUCA, though primitive, may have had more than 355 genes. If the investigators relax their search requirements a bit, they estimate that LUCA may have had nearly 575 genes.

    The German research team argued that not only was LUCA a thermophile, but that the origin of life occurred at hydrothermal vents.

    Have these researchers provided us with a key insight into LUCA’s identity? Have they identified the locale for the origin of life?

    Not necessarily. Here are some points to consider:

    In other words, there are good scientific reasons to question the high-temperature origin of life and the thermophilic identity of LUCA. And given the apparent complexity of LUCA, there is a strong basis to question evolutionary scenarios for life’s start.

    In spite of the headlines, scientists have no true understanding of how chemical evolution could have produced the first life on Earth.

    Resources
    Too Hot to Handle” by Fazale Rana (Article)
    Some Like It Hot—First Life Did Not” by Fazale Rana (Article)
    Sea Vents Closed as Life-Origin Site” by Fazale Rana (Article)
    Biochemists Ask, ‘How Low Can Life Go?’” by Fazale Rana (Article)
    Origins of Life by Fazale Rana and Hugh Ross (Book)
    Creating Life in the Lab by Fazale Rana (Book)

    Endnotes
    1. Madeline C. Weiss et al., “The Physiology and Habitat of the Last Universal Common Ancestor,” Nature Microbiology 1 (July 2016): 16116, doi:10.1038/NMICROBIOL.2016.116; James O. McInerney, “Evolution: A Four Billion Year Old Metabolism,” Nature Microbiology 1 (July 2016): 16139, doi:10.1038/NMICROBIOL.2016.139.
    2. Scientists think that LUCA was a prokaryotic, single-celled microbe.
  • Like a Fish Out of Water: Why I'm Skeptical of the Evolutionary Paradigm

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 27, 2016

    I am skeptical that evolutionary processes can fully account for life’s origin, history, and design—and that often makes me feel like a fish out of water.

    “Mainstream” scientists view biological evolution as the organizing principle in biology. In fact, Russian geneticist Theodosius Dobzhansky famously wrote, “Nothing in biology makes sense except in the light of evolution.”1 So, when I question evolutionary explanations, I become an outsider. I am outside the fish bowl, looking in. Because I’m a biochemist, my critics accuse me of being either dishonest or incompetent. Why else would I question the “fact” of evolution in the face of the overwhelming evidence for common descent? They claim that theological—not scientific motivations fuel my skepticism.

    I would partially agree with that assessment. I find it hard to square certain features of the evolutionary framework with some of Christianity’s most important biblical and theological ideas. But, I also think that there are some very real scientific problems associated with the evolutionary paradigm. The deficiencies are best exposed by failed predictions.

    From my perspective, the unpredicted pervasiveness of convergence justifies skepticism about evolution’s capacity to fully account for the history and diversity of life on Earth. Convergence stands as a failed prediction.

    Convergence

    One of evolution’s failed predictions relates to the phenomenon known as convergence. This concept describes instances in which unrelated organisms possess nearly identical anatomical and physiological characteristics. Presumably, evolutionary pathways independently produced these identical (or near identical) features. Yet convergence doesn’t make much sense from an evolutionary perspective. Indeed, if evolution is responsible for the diversity of life, one would expect convergence to be extremely rare. As a I wrote in a previous blog post, the mechanism that drives the evolutionary process consists of an extended sequence of unpredictable, chance events. Given this mechanism, it seems improbable that disparate evolutionary pathways would ever lead to the same biological feature. To put it another way, examples of convergence should be rare.

    The concept of historical contingency embodies the notion that evolution should be nonrepeatable, and is the theme of Stephen Jay Gould’s book Wonderful Life.2 To help clarify the concept of historical contingency, Gould used the metaphor of “replaying life’s tape.” If one were to push the rewind button, erase life’s history, and then let the tape run again, the results would be completely different each time.

    Yet, biological convergence is widespread.3 Recently, researchers from the University of New South Wales (in Australia) added to the examples of convergence at an organismal level. From an evolutionary perspective, they showed that amphibious behavior in fish evolved 33 separate times among extant groups! In fact, in one family, fish adopted a terrestrial life style between 3 to 7 times.

    This result was unexpected. One of the researchers involved with the study stated, “Because of the challenges fish face in being able to breathe and move and reproduce on land, it had been thought this was a rare occurrence.”4

    Recently, another team of investigators from the University of Kansas identified another example of biochemical convergence. They showed that venom evolved, separately and independently, 18 times in fish that live in freshwater and marine environments. This result is all the more surprising because—as William Leo Smith, one of the study’s authors points out— “fish venoms are often super complicated, big molecules.”5

    Does the Widespread Occurrence of Convergence Falsify Evolution?

    From my perspective, the unpredicted pervasiveness of convergence justifies skepticism about evolution’s capacity to fully account for the history and diversity of life on Earth. It stands as a failed prediction. Yet many evolutionary biologists don’t see it that way. For example, the scientists from the University of New South Wales responded to their unexpected find this way: “Now we have shown this initial transition to land is quite common, it seems these challenges can be readily overcome.”6 However, their interpretation entails circular reasoning. Biologists thought that fish moving to land would be difficult given the immense challenges associated with this transition. But, when it was found to be a frequent occurrence, then they conclude it must be easy. But they have no reason to think it must be easy other than the widespread occurrence of this transition. I would contend that this circular reasoning reflects a deep-seated, a priori commitment to the evolutionary paradigm, in which evolution is accepted as fact, and no evidence can ever count against it.

    Convergence and the Case for Intelligent Design

    Though the idea of convergence fits awkwardly within the evolutionary framework, it makes perfect sense if a Creator is responsible for life. Instead of convergent features emerging through repeated evolutionary outcomes, they could be understood as reflecting the work of a Divine mind. The repeated origins of biological features equate to the repeated creations by an intelligent Agent who employs a common set of solutions to address a common set of problems facing unrelated organisms.

    Resources
    The Cell’s Design (book)

    Endnotes
    1. Theodosius Dobzhansky, “Nothing in Biology Makes Sense Except in the Light of Evolution,” American Biology Teacher 35 (March 1971): 125–29.
    2. Stephen Jay Gould, Wonderful Life: The Burgess Shale and the Nature of History (New York: W.W. Norton & Company, 1990).
    3. Simon Conway Morris, Life’s Solution: Inevitable Humans in a Lonely Universe (New York: Cambridge University Press, 2003); George McGhee, Convergent Evolution: Limited Forms Most Beautiful (Cambridge, MA: MIT Press, 2011).
    4. University of New South Wales, “Fish Out of Water Are More Common Than Thought,” ScienceDaily, June 22, 2016, https://www.sciencedaily.com/releases/2016/06/160622102129.htm.
    5. University of Kansas, “Researchers Tally Huge Number of Venomous Fishes, Tout Potential for Medical Therapies,” ScienceDaily, July 5, 2016, https://www.sciencedaily.com/releases/2016/07/160705160206.htm.
    6. “Fish Out of Water,” ScienceDaily.
  • Historical Contingency and the Improbability of Protein Evolution, Part 2 (of 2)

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 20, 2016

    A few weeks ago, Kathy Emmons of WORD FM in Pittsburg interviewed me about the connection between human evolution and human trafficking. During the interview, she asked me if theological or scientific concerns drove my skepticism about human evolution. My answer is both.

    I find it difficult to reconcile the idea of human evolution with passages in the Old and New Testaments that address human origins. But, I also think that there are significant scientific problems confronting the evolutionary paradigm. A recent study by scientists from the Universities of Oregon and Chicago highlights one of those scientific challenges.1

    As described in a previous post, these researchers wanted to develop a better understanding of the role that chance historical events play in evolutionary processes. To do this, they reconstructed what they believe to be the evolutionary pathway that led to the emergence of the cortisol-specific glucocorticoid receptor protein, a key component of the vertebrate endocrine system. Based on their reconstruction, it appears that seven amino acid changes transformed the ancestral receptor protein into one that exclusively binds cortisol. They determined that two of the changes were permissive. That is, these changes do not contribute to the binding specificity of the glucocorticoid receptor, but must occur before any of the functional changes took place. Based on their analysis, it appears that the permissive changes were highly improbable, leading the researchers to conclude that historical contingency plays a central role in evolutionary transformations.

    According to the researchers:

    “If evolutionary history could be replayed from the ancestral starting point, the same kind of permissive substitutions would be unlikely to occur. The transition to GR’s [glucocorticoid receptor’s] present form and function would likely be inaccessible, and different outcomes would almost certainly ensue. Cortisol-specific signaling might evolve by a different mechanism in the GR . . . or the vertebrate endocrine system more generally—would be substantially different.”2

    Historical Contingency

    The concept of historical contingency is the theme of the late Stephen Jay Gould’s book Wonderful Life.3 According to this idea, the evolutionary process consists of an extended sequence of unpredictable, chance events. To help clarify this concept, Gould used the metaphor of “replaying life’s tape.” If one were to push the rewind button, erase life’s history, and then let the tape run again, the results would be completely different each time.

    Gould envisioned historical contingency as primarily resulting from external events (such as climate change or asteroid impacts). But this latest work indicates that the intrinsic complexity of proteins also contributes to historical contingency, because of the necessity and low probability of of permissive amino acid substitutions that support functional changes.

    How Widespread Is Historical Contingency?

    The question then becomes: How widely applicable is this result? The research team from the Universities of Oregon and Chicago expressed uncertainty regarding this point, but other studies indicate that historical contingency must play a prominent role in molecular evolution.

    For example, the long-term evolution experiment conducted by Richard Lenski’s group at Michigan State University demonstrated that the emergence of citrate metabolism in E. coli under aerobic conditions was historically contingent, predicated on a sequence of chance molecular events. (For more information, see the articles listed under “Resources.”)

    Using simulations to monitor the evolution of a protein dubbed argT, researchers from the University of Pennsylvania showed that genetic mutations selected by the evolutionary process are dependent on previous mutations, and over time it becomes increasingly difficult to reverse mutational transformations.4 In other words, an amino acid substitution that occurs in a protein today and is accepted by the evolutionary process would most likely be deleterious if it occurred in the past (because of the central role permissive substitutions play in evolutionary history). Consequently, this mutational change would be selected against by the evolutionary process. One of the researchers involved in this study, Joshua Plotkin, stated,

    “There is intrinsically a huge amount of contingency in evolution. Whatever mutations happen to come first set the stage for what other later mutations are permissible. Indeed, history channels evolution down a certain path. Gould’s famous tape of life would be very different if replayed, even more different than Gould might have imagined.”5

    A Failed Prediction of the Evolutionary Paradigm

    Because the evolutionary process is historically contingent, it seems unlikely that evolutionary processes would lead to identical or nearly identical outcomes. Yet, when viewed from an evolutionary standpoint, it appears as if repeated evolutionary outcomes have been a common occurrence throughout life’s history. This phenomenon—referred to as convergence—is widespread. Evolutionary biologists Simon Conway Morris and George McGhee point out in their respective books Life’s Solution and Convergent Evolution, that identical evolutionary outcomes are a characteristic feature of the biological realm.6 Scientists see these repeated outcomes at the ecological, organismal, biochemical, and genetic levels. In fact, in my book The Cell’s Design, I describe 100 examples of convergence at the biochemical level.

    I regard the widespread occurrence of convergence to one of evolution’s failed predictions, and, as I told Kathy Emmons, a justifiable reason to be skeptical of the claim that evolutionary processes can fully explain the history, diversity, and design of life.

    In an upcoming blog post, I will further explore the challenge convergence poses for the evolutionary paradigm.

    Stay tuned… (or set your tape player to “record.”)

     

    Resources

    Endnotes
    1. Michael Harms and Joseph Thornton, “Historical Contingency and Its Biophysical Basis in Glucocorticoid Receptor Evolution,” Nature 512 (August 2014): 203–07, doi:10.1038/nature13410.
    2. Ibid., 207.
    3. Stephen Jay Gould, Wonderful Life: The Burgess Shale and the Nature of History (New York: W.W. Norton & Company, 1990).
    4. Premal Shah, David McCandlish, and Joshua Plotkin, “Contingency and Entrenchment in Protein Evolution under Purifying Selection,” Proceedings of the National Academy of Sciences, USA 112 (June 2015): E3226–E3235, doi: 10.1073/pnas.1412933112.
    5. University of Pennsylvania, “Evolution Is Unpredictable and Irreversible, Biologists Show,” ScienceDaily, June 8, 2015, sciencedaily.com/releases/2015/06/150608213032.htm.
    6. Simon Conway Morris, Life’s Solution: Inevitable Humans in a Lonely Universe (New York: Cambridge University Press, 2003); George McGhee, Convergent Evolution: Limited Forms Most Beautiful (Cambridge, MA: MIT Press, 2011).
  • Science News Flash: Stone Tool Use by Capuchin Monkeys Challenges Human Evolution

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 14, 2016

    I love cashew nuts! Apparently, so do capuchin monkeys.

    A team of scientists from Oxford University (in the UK) and the University of Sao Paulo (in Brazil) report that capuchin monkeys in the northeast forests of Brazil make sophisticated use of stone tools to extract cashew nuts from shells.1

    These researchers claim that this find sheds light on the evolution of human behavior. However, I take a different view. I maintain that this discovery actually undermines the standard model for human evolution. At the same time, this work highlights human exceptionalism, which finds ready explanation in the biblical human origins account.2

    Tools Engender New Scientific Possibilities

    This discovery, reported in the journal Current Biology, has found its way into popular science outlets, spurring headlines such as “Scientists Unearthed a Trove of 700-Year-Old Stone Tools—Used by Monkeys.” And with good reason. It is the first archaeological evidence for the use of stone tools by nonhuman primates outside of Africa, suggesting a whole new arena of scientific investigation. Lydia Luncz, a member of the research team, stated, “We think we’re just at the beginning.”3

    To get to cashew nuts, capuchins go through an elaborate process. These monkeys carefully select large flat sandstones and quartzite to use as an anvil and hammer, respectively. They transport these stones to the base of the cashew trees. There, they place the cashew nut on the flat anvil (which is about four times the size of the hammer) and carefully strike the shell with the hammer (which is about four times the size of an average stone) breaking it open so they can get to the nut inside. Once they are done with the tools, the capuchins leave them at the base of cashew trees. A walk through the forest reveals a number of cashew nut processing centers, established by these industrious creatures.

    To determine how long capuchins have engaged in this behavior, the research team excavated beneath several cashew trees located in the Brazilian forest. They discovered stone tools at least 2 feet beneath the surface that date back to about 700 years old. The excavated tools had a dark organic residue on them. Analysis of the residue indicates that it is the leftover remnants of cashew nuts, confirming the use of these stones as tools. Based on the excavations, it appears that about 100 generations of capuchins have employed stone tools to extract cashews from shells. It is reasonable to think that this behavior extends even further back in time.

    This discovery follows on the heels of earlier work by the same team. In a previous study, these scientists observed Burmese long-tailed macaques in Thailand using stone tools to crack open shellfish, crabs, and nuts. Excavations at macaque sites on the island of Piak Nam Yai have identified stone tools that are about 65 years in age, going back two generations.

    The use of stone tools among nonhuman primates is not limited to capuchins and macaques. Researchers have also uncovered evidence for chimpanzee stone tool use in Africa that dates back to over 4,000 years ago.

    It seems as if hominids aren’t the only primates to leave behind an archaeological record.

    Tools Throw Evolution into Question

    The use of stone tools by capuchins, macaques, and chimpanzees has important implications for the creation-evolution debate. The tools used by these nonhuman primates is reminiscent of tools used by hominids. The similar behavior of hominids, Great Apes, and Old and New World monkeys renders the activities of hominids much less remarkable. I wrote elsewhere about the implications of tool use by chimpanzees (see here). The point I raised applies to the use of stone tools by capuchins and macaques:

    “Chimpanzee behavior is closer to what we infer about hominid behavior from the fossil record, particularly Homo habilis and Homo erectus. These creatures, too, made tools and engaged in hunting and scavenging activity. The temptation is to see hominid behavior as transitional, representing a path to modern human behavior. Yet the newly recognized behavior of chimpanzees distances the hominids from modern humans. Just because the habilines and erectines made tools and engaged in other remarkable behaviors doesn’t mean that they were ‘becoming human.’ Instead, their behavior appears to be increasingly animal-like, particularly when compared to chimp activities.”4

    And, I would add, hominid behavior becomes even more animal-like when compared to the behavior of capuchins and macaques.

    Resources
    Who Was Adam? (book)
    Chimpanzee’s Behavior Supports RTB’s Model for Humanity’s Origin” (article)
    Chimpanzees’ Sleeping Habits Closer to Hominid Behavior Than to Humans’” (article)

    Endnotes
    1. Michael Haslam et al., “Pre-Columbian Monkey Tools,” Current Biology 26 (July 2016): pR521–R522, doi:10.1016/j.cub.2016.05.046.
    2. RTB’s biblical creation model for human origins views the hominids as creatures, created by God’s divine fiat, possessing intelligence and emotional capacity. These animals were able to employ crude tools and even adopt some level of “culture,” much like baboons, gorillas, and chimpanzees. But they were not spiritual beings made in God’s image. That position—and all of the intellectual, relational, and symbolic capabilities that come with it—remains reserved for modern humans alone.
    3. Darryl Fears, “Scientists Unearthed a Trove of 700-Year-Old Stone Tools—Used by Monkeys,” The Washington Post, July 11, 2016, https://www.washingtonpost.com/news/animalia/wp/2016/07/11/in-brazil-scientists-unearth-a-trove-of-ancient-stone-tools-used-by-monkeys/.
    4. Fazale Rana, “Chimpanzees’ Sleeping Habits Closer to Hominid Behavior Than to Humans,'” Today’s New Reason to Believe (blog), Reasons to Believe, June 9, 2014, https://www.reasons.org/articles/chimpanzees-sleeping-habits-closer-to-hominid-behavior-than-to-humans.
  • Historical Contingency and the Improbability of Protein Evolution, Part 1 (of 2)

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 13, 2016

    Can evolutionary processes produce biological innovation?

    Critics of the evolutionary paradigm—including me—would say, “No.” However, the reasons for my skepticism differ from many of evolution’s chief detractors. One argument against the evolutionary paradigm that causes me discomfort has to do with the “improbability” of the evolutionary process. For example, one common version of this argument relates to the evolutionary emergence of proteins, with critics asserting that the evolution of novel proteins from preexisting proteins would have been so improbable that it defies an evolutionary explanation. To justify this position, these critics often point to studies such as the one published by scientists from the Universities of Oregon and Chicago that seemingly buttresses their point.1 But does it?

    The Evolutionary Origin of a Protein Receptor

    This research team hoped to gain insight into the role that chance historical events play in evolutionary processes. Working within the framework of the evolutionary paradigm, they determined what they believe to be the amino acid sequence and structure of the ancestral protein that evolved into the cellular receptor protein that binds the hormone cortisol. They claim to have resurrected an ancient protein they believe existed 450 million years ago, before the cortisol-specific glucocorticoid receptor evolved its specificity for this particular hormone.2

    Today, the cortisol-specific glucocorticoid receptor assumes a key role in the endocrine system by regulating development and the stress response. The activity of this protein is mediated by cortisol binding. However, the researchers believe that in the past the ancestral protein was biochemically promiscuous, binding a number of hormones, and only later evolved its specificity for cortisol through amino acid changes mediated by the putative evolutionary process. Based on a reconstruction of the evolutionary pathway, they conclude that seven amino acid changes transformed the ancestral receptor protein into one that exclusively binds cortisol.

    The researchers classified the changes into two categories: 1) functional; and 2) permissive. They deemed five of the changes as functional, meaning that these changes contributed to the receptor’s cortisol-binding specificity. They dubbed the other two changes as permissive. These changes do not contribute to the binding specificity of the glucocorticoid receptor, but must occur for the functional changes to take effect. In other words, if the functional changes took place independently of the permissive changes, the resulting hormone receptor would not bind cortisol. The researchers determined that the permissive changes help to stabilize the receptor protein’s structure so that it can tolerate the five functional changes.

    Because cortisol binding depends upon the permissive mutations, the researchers reasoned that historical contingency must have played some role in the evolution of the cortisol-specific receptor protein. The permissive mutations must have appeared first, because if they didn’t, the functional changes would not have been selected (again) since they aren’t functional apart from the permissive changes.

    The Improbability of Protein Evolution

    The question then becomes, “How prominent is contingency in the evolutionary history of the cortisol-specific receptor protein?” To address this point, the investigators synthesized the ancestral receptor protein with the five functional amino acid changes (AP+5). Then, they subjected the AP+5 protein to random amino acid changes to try and determine the number of possible alternate permissive changes that could stabilize the receptor protein in the same way as the historical permissive changes.

    They screened about 12,500 random variants of the AP+5 protein. These variants yielded an estimated 1,025 unique single amino acid replacements, 1,802 unique double amino acid replacements, and 825 unique higher order combinations of amino acid substitutions. That is, they examined about 3,650 variants of the AP+5 protein. (The other 8,850 variants were duplicates of the 3,650 variants.) They also engineered 10 additional AP+5 variants using rational design principles. To their surprise, none of the 3,660 variants (3,650 in the screened library, plus the additional 10 engineered double mutants) yielded a functional cortisol-specific receptor that would not disrupt the function of the ancestral protein. (Four of the AP+5 variants displayed cortisol-specific binding, but these four changes destroyed the function of the ancestral protein. From an evolutionary perspective, these alternate permissive substitutions would have been selected against because of their disruptive influence.)

    This result indicates that it is highly improbable that the permissive amino acid changes necessary to support the evolution of a cortisol-specific receptor protein could ever occur (with an upper bound of 0.03 percent). The researchers conclude:

    “The total frequency is probably far lower…The universe of possible variants containing two or more replacements is very large, so alternative permissive sets may exist; however, these genotypes would require multiple independent substitutions, and the joint probability of such events would be very low because they cannot be acquired deterministically by selection for the derived function.”3

    Their probability assessment doesn’t even include the likelihood of the five functional changes occurring after the two permissive changes took place, meaning that the probabilities for the evolution of the cortisol-specific receptor protein from a promiscuous ancestral receptor are even more unlikely.

    The Contingency of the Evolutionary Process

    As a skeptic of the evolutionary paradigm, it is tempting to point to this study as evidence that evolutionary transformations are so improbable that these processes cannot account for biological innovation. But this would be an unfair conclusion that misrepresents the way evolutionary biologists interpret these results. Instead, these scientists argue that these results tell them something about the evolutionary process: Namely, that historical contingency plays a central role in evolutionary transformations.

    The concept of historical contingency is the theme of the late Stephen Jay Gould’s book Wonderful Life.4 According to this idea, the mechanism that drives the evolutionary process consists of an extended sequence of unpredictable, chance events. To help clarify this concept, Gould used the metaphor of “replaying life’s tape.” If one were to push the rewind button, erase life’s history, and then let the tape run again, the results would be completely different each time.

    According to the researchers:

    “If evolutionary history could be replayed from the ancestral starting point, the same kind of permissive substitutions would be unlikely to occur. The transition to GR’s [glucocorticoid receptor’s] present form and function would likely be inaccessible, and different outcomes would almost certainly ensue. Cortisol-specific signaling might evolve by a different mechanism in the GR—or the vertebrate endocrine system more generally—would be substantially different.”5

    A Flawed Argument

    In other words, while evolutionary transformations are highly improbable, their unlikelihood cannot be used as a legitimate basis for skepticism about the evolutionary paradigm. To use them in this way would be to make a straw man argument against biological evolution. This probability argument assumes that evolutionary end points are fixed, but evolutionary biologists don’t see them that way at all—because of the historically contingent nature of the process.

    Still, there are some legitimate reasons to be skeptical about the capacity of evolutionary mechanisms to account for the design and diversity of life. And one of those reasons is exposed by this study and the historically contingent nature of the evolutionary process.

    I will elaborate in my next blog post.

    Resources

    Endnotes
    1. Michael Harms and Joseph Thornton, “Historical Contingency and Its Biophysical Basis in Glucocorticoid Receptor Evolution,” Nature 512 (August 2014): 203–7.
    2. For a Christian perspective on resurrected ancient proteins, see my article, Fazale Rana, “Resurrected Proteins and the Case for Biological Evolution,” Today’s New Reason to Believe (blog), Reasons to Believe, October 14, 2013, https://www.reasons.org/articles/resurrected-proteins-and-the-case-for-biological-evolution.
    3. Harms and Thornton, “Historical Contingency,” 204.
    4. Stephen Jay Gould, Wonderful Life: The Burgess Shale and the Nature of History (New York: W. W. Norton & Company, 1990).
    5. Harms and Thornton, “Historical Contingency,” 207.
  • Science News Flash: Reinterpretation of Sea Worm Fossil Challenges Evolution

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 08, 2016

    In a recent article published by the BBC, researchers from the University of Toronto announced the reinterpretation of an enigmatic fossil, Oesia disjuncta, now classifying this creature as a hemichordate.1 They also now think that tube-like structures, originally thought to be a type of seaweed, were made by Oesia.

    This reinterpretation was based on the recovery of new fossil specimens from Marble Canyon in the Canadian Rockies. Oesia disjuncta is part of a fossil assemblage known as the Cambrian explosion, so researchers estimate the creature’s age to be around 510 million years old. (The Cambrian explosion refers to a dramatic event in life’s history in which 50 to 80 percent of all known animal phyla appear in a geological instant.)

    According to lead researcher in the study, Karma Nanglu:

    Hemichordates are central to our understanding of how deuterostomes evolved.2

    I would partially agree with Nanglu: Hemichordate fossils are central to our understanding of life’s history; but instead of shedding light on evolutionary history, I would maintain that the appearance of this phylum during the Cambrian explosion creates problems for the evolutionary paradigm. (To learn why I hold this view see my article “Cambrian Flash.”) At the same time, this find adds to the evidence for the scientific credibility of the Genesis 1 creation account. (For details see my article “The ‘Great Unconformity’ and the Cambrian Explosion Conform to the Genesis 1 Creation Account.”)

    For more on the Cambrian explosion, check out the following resources.

    Endnotes
    1. Karma Nanglu et al., “Cambrian Suspension-Feeding Tubicolous Hemichordates,” BMC Biology 14 (July 2016): 56, doi: 10.1186/s12915-016-0271-4.
    2. “Sea Worm Fossil Gives Clues to ‘Common Ancestor,’” Science & Environment (blog), BBC News, July 7, 2016, https://www.bbc.com/news/science-environment-36724562.
  • Adam and Eve: A Primordial Pair or a Population?

    by Telerik.Sitefinity.DynamicTypes.Model.Authors.Author | Jul 06, 2016

    Today, one of the central science-faith issues facing evangelical Christianity centers around the historicity of Adam and Eve. Did Adam and Eve actually exist? Or are they merely mythical, functioning as theological constructs meant to represent every man and every woman? And if they did exist, were they the primordial pair that gave rise to all humanity? Or were they representatives, part of a population?

    My ministry activities during the month of June reminded me of the importance of these questions. I participated in the Dabar Conference, which centered on “Reading Genesis in an Age of Science,” so naturally, there was much discussion about the identity of Adam and Eve. I also taught a weeklong intensive course for Southern Evangelical Seminary on the biblical and scientific perspectives on human origins. As part of the course, we explored the scientific case for Adam and Eve’s historicity and the importance of this idea for the Christian faith. And finally, at the end of the month, I taught at the RZIM Summer Institute, where we examined the relationship between the biblical account of human origins and the key tenets of Christian ethics.

    Adam and Eve’s existence and relationship to humanity are not merely academic concerns. Instead, these questions influence key doctrines of the Christian faith such as: inerrancy, the image of God, the Fall, original sin, marriage, and the atonement. Because of the importance of a historical Adam and Eve to the Christian faith, it is important to be able to demonstrate the scientific credibility of the biblical view of human origins.

    A Scientific Case for a Historical Adam and Eve

    Part of the scientific support for the traditional biblical view comes from work in molecular anthropology. One of the most important advances in human origins research has been the use of DNA sequence data to gain insight into the origin and early history of humanity.

    Of particular interest are the results of mitochondrial DNA and Y-chromosomal studies that trace humanity’s origin to single ancestral sequences referred to as “mitochondrial Eve” and “Y-chromosomal Adam.” These ancestral sequences correspond to single female and male individuals. I interpret mitochondrial Eve and Y-chromosomal Adam as pointers to the biblical Adam and Eve.

    Many evolutionary biologists reject the notion that mitochondrial Eve and Y-chromosomal Adam were the original biblical couple. Instead, they argue that human beings originated as a population. Accordingly, there were many “Eves” and “Adams.” In other words, we descend from the two who were lucky enough for their genetic material to persist to the present. The genetic lines of the other first humans were lost over time.

    Perhaps most challenging to the view that mitochondrial Eve and Y-chromosomal Adam are the biblical Adam and Eve are the population size estimates determined from human genetic diversity data. These methods all indicate that the initial human population size was never less than several thousand individuals. It is largely based on these results that evolutionary biologists argue that mitochondrial Eve and Y-chromosomal Adam weren’t the primordial pair.

    5 Reasons Why Humanity Didn’t Begin as a Population

    Evolutionary biologists argue for this mainstream idea (that there were many first humans, not just two), but I’m reluctant to accept these claims for a number of reasons.1

    1. The idea that humanity arose as a population is a theory-laden concept that is a necessary entailment of the evolutionary paradigm. Biologists view evolution as a population-level phenomenon. Populations evolve, individuals don’t. As a consequence, there can’t be a primordial pair—if one views human origins from an evolutionary framework. To put it another way, humans must have emerged from a population by definition.
    2. The methods used to determine population sizes rely on simplified and idealized mathematical models that are highly sensitive to input parameters. Because of that the population numbers need to be viewed as rough estimates, at best.
    3. These models do a poor job in taking into account the effects of population structure, migrations, and gene flow all of which can lead to misleading population size calculations.2
    4. Population size methods have not been validated. That is, there are not any studies that demonstrate that these methods produce accurate results for population size estimates, when applied to known situations. Studies in conservation biology suggest that these models don’t accurately predict genetic variability when the original population size is known. As a case in point, in three separate studies involving Mouflon sheep, Przewalski’s horses, and gray whales, genetic diversity (measured generations after the initial population) was much greater than expected based on the models.
    5. Other studies in conservation biology raise questions about the validity of the mathematical relationships that undergird the population size methods. In fact, these concerns prompted one research team to question if these problems invalidate population size estimates in humans. These researchers state, “Recently, however, Bazin et al. (2006) have argued that mtDNA variation is a poor indicator of population size in animals. . . . This raises the question of whether mtDNA is in fact a reliable predictor of human population size.”3

    Did Humanity Begin as a Pair?

    Because of the central importance of Adam and Eve’s historicity to the Christian faith, I am reluctant to embrace the idea that humanity began as a population, not a pair. But, I’m as equally reluctant to accept this scientific claim—mainstream or not—knowing that the population size measurements are based on simplified, idealized methods that struggle to take into account population dynamics that can influence population size estimates and haven’t been validated. Questions about the validity of the mathematical relationships that form the basis of these methods compound these problems. To put it another way: Even if I accepted the notion of common descent, I still wouldn’t be convinced that humans arose as a population because of the scientific questions that surround the population size estimates.

    In my view, science has yet to falsify the notion that humanity descended from a primordial pair.

    Resources

    Endnotes
    1. Some of my concerns with population size estimates are also detailed in the article, Fazale Rana, “Were They Real? The Scientific Case for Adam and Eve,” Today’s New Reason to Believe (blog), Reasons to Believe, October 1, 2010, https://www.reasons.org/articles/were-they-real-the-scientific-case-for-adam-and-eve.
    2. For example, see Olivier Mazet et al., “On the Importance of Being Structured: Instantaneous Coalescence Rates and Human Evolution—Lessons for Ancestral Population Size Inference?” Heredity 116 (April 2016): 362–71, doi:10.1038/hdy.2015.104; Thomas Broquet et al., “Genetic Bottlenecks Driven by Population Disconnection,” Conservation Biology 24 (December 2010): 1596–1605, doi:10.1111/j.1523-1739.2010.01556.x.
    3. Quentin Atkinson, Russell Gray, and Alexei Drummond, “mtDNA Variation Predicts Population Size in Humans and Reveals a Major Southern Asian Chapter in Human Prehistory,” Molecular Biology and Evolution 25 (February 2008): 468–74, doi:10.1093/molbev/msm277.

About Reasons to Believe

RTB's mission is to spread the Christian Gospel by demonstrating that sound reason and scientific research—including the very latest discoveries—consistently support, rather than erode, confidence in the truth of the Bible and faith in the personal, transcendent God revealed in both Scripture and nature. Learn More »

Support Reasons to Believe

Your support helps more people find Christ through sharing how the latest scientific discoveries affirm our faith in the God of the Bible.

Donate Now

U.S. Mailing Address
818 S. Oak Park Rd.
Covina, CA 91724
  • P (855) 732-7667
  • P (626) 335-1480
  • Fax (626) 852-0178
Reasons to Believe logo