Are you a Marvel or a DC fan?
Do you like the Marvel superheroes better than those who occupy the DC universe? Or is it the other way around for you?
Even though you might prefer DC over Marvel (or Marvel over DC), over the years these two comic book rivals have often created superheroes with nearly identical powers. In fact, a number of Marvel and DC superheroes are so strikingly similar that their likeness to one another is obviously intentional.1
Here are just a few of the superheroes Marvel and DC have ripped off each other:
- Superman (DC, created in 1938) and Hyperion (Marvel, created in 1969)
- Batman (DC, created in 1939) and Moon Knight (Marvel, created in 1975)
- Green Lantern (DC, created in 1940) and Nova (Marvel, created in 1976)
- Catwoman (DC, created in 1940) and Black Cat (Marvel, created in 1979)
- Atom (DC, created in 1961) and Ant-Man (Marvel, created in 1962)
- Aquaman (DC, created in 1941) and Namor (Marvel, created in 1939)
- Green Arrow (DC, created in 1941) and Hawkeye (Marvel, created in 1964)
- Swamp Thing (DC, created in 1971) and Man Thing (Marvel, created in 1971)
- Deathstroke (DC, created in 1980) and Deadpool (Marvel, created in 1991)
This same type of striking similarity is also found in biology. Life scientists have discovered countless examples of biological designs that are virtually exact replicas of one another. Yet, these identical (or nearly identical) designs occur in organisms that belong to distinct, unrelated groups (such as the camera eyes of vertebrates and octopi). Therefore, they must have an independent origin.
Figure 1: The Camera Eyes of Vertebrates (left) and Cephalopods (right); 1: Retina; 2: Nerve Fibers; 3: Optic Nerve; 4: Blind Spot. Image credit: Wikipedia
From an evolutionary perspective, it appears as if the evolutionary process independently and repeatedly arrived at the same outcome, time and time again. As evolutionary biologists Simon Conway Morris and George McGhee point out in their respective books, Life’s Solution and Convergent Evolution, identical evolutionary outcomes are a widespread feature of the biological realm.2 Scientists observe these repeated outcomes (known as convergence) at the ecological, organismal, biochemical, and genetic levels.
From my perspective, the widespread occurrence of convergent evolution is a feature of biology that evolutionary theory can’t genuinely explain. In fact, I see pervasive convergence as a failed scientific prediction—for the evolutionary paradigm. Recent work by a research team from Stanford University demonstrates my point.3
These researchers discovered that identical genetic changes occurred when: (1) bats and whales “evolved” echolocation, (2) killer whales and manatees “evolved” specialized skin in support of their aquatic lifestyles, and (3) pikas and alpacas “evolved” increased lung capacity required to live in high-altitude environments.
Why do I think this discovery is so problematic for the evolutionary paradigm? To understand my concern, we first need to consider the nature of the evolutionary process.
Biological Evolution Is Historically Contingent
Essentially, chance governs biological and biochemical evolution at its most fundamental level. Evolutionary pathways consist of a historical sequence of chance genetic changes operated on by natural selection, which, too, consists of chance components. The consequences are profound. If evolutionary events could be repeated, the outcome would be dramatically different every time. The inability of evolutionary processes to retrace the same path makes it highly unlikely that the same biological and biochemical designs should appear repeatedly throughout nature.
The concept of historical contingency embodies this idea and is the theme of Stephen Jay Gould’s book Wonderful Life.4 To help illustrate the concept, Gould uses 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.
Are Evolutionary Processes Historically Contingent?
Gould based the concept of historical contingency on his understanding of the evolutionary process. In the decades since Gould’s original description of historical contingency, several studies have affirmed his view.
For example, in a landmark study in 2002, two Canadian investigators simulated macroevolutionary processes using autonomously replicating computer programs, with the programs operating like digital organisms.5 These programs were placed into different “ecosystems” and, because they replicated autonomously, could evolve. By monitoring the long-term evolution of the digital organisms, the two researchers determined that evolutionary outcomes are historically contingent and unpredictable. Every time they placed the same digital organism in the same environment, it evolved along a unique trajectory.
In other words, given the historically contingent nature of the evolutionary mechanisms, we would expect convergence to be rare in the biological realm. Yet, biologists continue to uncover example after example of convergent features—some of which are quite astounding.
The Origin of Echolocation
One of the most remarkable examples of convergence is the independent origin of echolocation (sound waves emitted from an organism to an object and then back to the organism) in bats (chiropterans) and cetaceans (toothed whales). Research indicates that echolocation arose independently in two different groups of bats and also in the toothed whales.
Figure 2: Echolocation in Bats. Image credit: Shutterstock
One reason why this example of convergence is so remarkable has to do with the way some evolutionary biologists account for the widespread occurrences of convergence in biological systems. Undaunted by the myriad examples of convergence, these scientists assert that independent evolutionary outcomes result when unrelated organisms encounter nearly identical selection forces (e.g., environmental, competitive, and predatory pressures). According to this idea, natural selection channels unrelated organisms down similar pathways toward the same endpoint.
But this explanation is unsatisfactory because bats and whales live in different types of habitats (terrestrial and aquatic). Consequently, the genetic changes responsible for the independent emergence of echolocation in the chiropterans and cetaceans should be distinct. Presumably, the evolutionary pathways that converged on a complex biological system such as echolocation would have taken different routes that would be reflected in the genomes. In other words, even though the physical traits appear to be identical (or nearly identical), the genetic makeup of the organisms should reflect an independent evolutionary history.
But this expectation isn’t borne out by the data.
Genetic Convergence Parallels Trait Convergence
In recent years, evolutionary biologists have developed interest in understanding the genetic basis for convergence. Specifically, these scientists want to understand the genetic changes that lead to convergent anatomical and physiological features (how genotype leads to phenotype).
Toward this end, a Stanford research team developed an algorithm that allowed them to search through entire genome sequences of animals to identify similar genetic features that contribute to particular biological traits.6 In turn, they applied this method to three test cases related to the convergence of:
- echolocation in bats and whales
- scaly skin in killer whales
- lung structure and capacity in pikas and alpacas
The investigators discovered that for echolocating animals, the same 25 convergent genetic changes took place in their genomes and were distributed among the same 18 genes. As it turns out, these genes play a role in the development of the cochlear ganglion, thought to be involved in echolocation. They also discovered that for aquatic mammals, there were 27 identical convergent genetic changes that occurred in same 15 genes that play a role in skin development. And finally, for high-altitude animals, they learned that the same 25 convergent genetic changes occurred in the same 16 genes that play a role in lung development.
In response to this finding, study author Gill Bejerano remarked, “These genes often control multiple functions in different tissues throughout the body, so it seems it would be very difficult to introduce even minor changes. But here we’ve found that not only do these very different species share specific genetic changes, but also that these changes occur in coding genes.”7
In other words, these results are not expected from an evolutionary standpoint. It is nothing short of amazing that genetic convergence would parallel phenotypic convergence.
On the other hand, these results make perfect sense from a creation model vantage point.
Convergence and the Case for Creation
Instead of viewing convergent features as having emerged through repeated evolutionary outcomes, we could understand them as reflecting the work of a Divine Mind. In this scheme, 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.
Like the superhero rip-offs in the Marvel and DC comics, the convergent features in biology appear to be intentional, reflecting a teleology that appears to be endemic in living systems.
Convergence of Echolocation
The Historical Contingency of the Evolutionary Process