Newly Discovered Example of Convergence Challenges Biological Evolution
I love TiVo. It’s a lot of fun to pause live TV (particularly when the big game is on), rewind it, and play it back again.
Biological evolution has nothing in common with TiVo, however. As the late evolutionary biologist Stephen Jay Gould highlighted in his book Wonderful Life, 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.
The very essence of the evolutionary process renders evolutionary outcomes nonrepeatable. According to the concept of historical contingency, chance governs biological and biochemical evolution at its most fundamental level. Evolutionary pathways consist of an historical sequence of chance genetic changes operated on by natural selection, which, too, consists of chance components. As a consequence, 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 among unrelated organisms.
Contrary to what’s expected, evolutionary biologists note that biological convergence is widespread. As I noted last week, convergence refers to the extensive pattern in nature where unrelated organisms possess nearly identical anatomical, physiological, behavioral, and biochemical characteristics. According to the evolutionary paradigm, undirected natural processes yielded the identical outcome because the forces of selection channeled evolutionary pathways to the same endpoint.
Researchers Brian Beatty and Bruce Rothschild have uncovered another remarkable example of biological convergence. From an evolutionary standpoint, it appears as if toothed and baleen whales developed the ability to dive deep into the ocean independently from each other. (Go here for a popular article on this discovery and here for a technical paper.)
For whales to dive, they must have physiological adaptations that allow them to avoid decompression syndrome. Rapid pressure changes—such as what occur during deep diving—can force air bubbles out of the blood vessels. When this happens, it can cause the blood vessels to rupture, denying cells of blood, oxygen, and nutrients. This loss causes the cells to die, leaving lesions behind.
The scientists used this principle to assess susceptibility of ancient whales to decompression syndrome. They analyzed vertebrae of 331 individual modern and 996 fossil whales. The conclusion was that the two lineages of whales must have evolved the ability to avoid decompression syndrome independently. This scenario contravenes the expectation of most evolutionary biologists, who postulated that the shared ancestor of toothed and baleen whales must have had the ability to dive deep without suffering from decompression problems.
According to Erich Fitzgerald, an Australian paleontologist, “They have come up with a quite surprising story.” The surprise expressed by Fitzgerald stems from the notion that evolutionary outcomes should not repeat. Yet, in this instance and others it appears as though evolution has generated the same outcomes over and over again.
Biological convergence not only raises questions about the validity of biological evolution, it also points to the work of a Creator. As I argue in my new book The Cell’s Design designers and engineers frequently reapply successful strategies when they face closely related problems. Why reinvent the wheel? It’s much more prudent and efficient for an inventor to reuse the same good designs as much as possible, particularly when confronted with a problem he or she has already solved.
The tendency of engineers and designers to reuse the same designs provides insight into the way that a Creator might work. If human engineers, made in God’s image, reutilize the same techniques and technologies when they invent, it’s reasonable to expect that a Creator would do the same. If life stems from the work of a Creator then it’s reasonable to expect that the same designs would repeatedly appear throughout nature. Use of good, effective designs over and over again would reflect His prudence and efficiency as a Divine Engineer.
It looks as if life is God’s TiVo.
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