Will the Real Human Ancestor Please Stand Up?

Will the Real Human Ancestor Please Stand Up?

A  favorite episode of The Twilight Zone, titled “Will the Real Martian Please Stand Up?”, features two state troopers in a desolate diner looking for a disguised Martian among seven Boston-bound bus passengers stranded by a snowstorm. As they wait for the bridge to become passable, the travelers become mutually suspicious of each other as they try to guess who among them is the creature from Mars.

With the availability of the complete human, chimpanzee, rhesus monkey, and orangutan genomes (plus portions of the gorilla genome), evolutionary biologists find themselves in the same predicament as the state troopers. Comparative analysis of the genomes raises questions about who among the great apes is the closest evolutionary ancestor to humans. And this uncertainty provides a compelling reason to be suspicious about the evolutionary paradigm.

The Best Evidence for Human Evolution?

It is commonly reported that humans and chimps share 99 percent genetic similarity. For many people, this high degree of genetic similarity means humans must have evolved from an ape-like primate, sharing a common ancestor with chimpanzees. However, it should be noted that, when comparing the full genomes of humans and chimps, around one quarter of the two genomes don’t align and the similarity of those portions that do align is between 90 and 95 percent. (Go here and here for comparisons.)

According to the evolutionary model, humans and chimps share a common ancestor with gorillas. And humans, chimps, and gorillas share a common ancestor with orangutans. These presumed evolutionary relationships should be reflected in genetic comparisons between humans and the great apes, where scientists expect to find gorillas and orangutans displaying less similarity, respectively, to humans than to chimpanzees.

Yet, this is not always the case. Researchers have recently discovered that about one percent of the human genome displays a greater genetic similarity to orangutans than it does to chimpanzees.1 This result follows on the heels of an earlier study that found that 23 percent of random sequences sampled from the human genome point to a primate other than chimpanzees as our closest evolutionary relative.2 In other words, depending on the region of the genome that is selected, differing “evolutionary trees” result for humans and the great apes.

The evidence does not support a key idea of the evolutionary paradigm; namely, that evolutionary trees built from separate DNA sequences should agree with each other and with those constructed from morphology (form). This disagreement is more profound than it seems on the surface. It can be taken as evidence for creation. According to the late evolutionary biologist Morris Goodman in an article he wrote for The Cambridge Encyclopedia of Human Evolution:

If the biblical account of creation were true, then independent features of morphology, proteins, and DNA sequences would not be expected to be congruent with each other. Chaotic patterns, with different proteins and different DNA sequences failing to indicate any consistent set of species relationships, would contradict the theory of evolution. 3

And when it comes to genome comparisons between humans and the great apes, chaotic patterns abound. A couple of levelheaded state troopers could have figured that one out.

  1. Asger Hobolth et al., “Incomplete Lineage Sorting Patterns among Human, Chimpanzee, and Orangutan Suggest Recent Orangutan Speciation and Widespread Selection,” Genome Research (2011), doi:cgi/10.1101/gr.114751.110.
  2. Ingo Ebersberger et al., “Mapping Human Genetic Ancestry,” Molecular Biology and Evolution 24 (2007): 2266–76.
  3. Morris Goodman, “Reconstructing Human Evolution from Proteins,” in The Cambridge Encyclopedia of Human Evolution, Steve Jones, Robert Martin, and David Pilbeam, eds., (New York: Cambridge University Press, 1992), 307–13.