OPINION Sastry: Evolution supported by extensive evidence – The Daily Toreador (registration)

Editors note: This is the second part of a two-column series about debunking creationism.

[Click here to read part one: "Religion-based 'creationism' debasement of science"]

In his book The Greatest Show on Earth: The Evidence for Evolution, evolutionary biologist Richard Dawkins remarks denying evolution is much like denying the Holocaust. Is he right?

At first, Dawkins claim seems preposterous. So, in order to further investigate the issue, it seems worthwhile to ask the question: Why do people readily accept the idea of Holocaust but not of evolution? Do the varying degrees of belief correspond neatly with different amounts of evidence available to support each case?

Not surprisingly, this turns out not to be true, as the proof for evolution is plentiful and steadily mounting. Evidently, some people tend to shy away from evolution because the evolutionary theory, unlike an account of the Holocaust, has the potential to encroach on and disturb ones religious beliefs.

For a person whose entire worldview is based on faith, no amount of evidence is sufficient.

The evidence for evolution can broadly be categorized into testable predictions and retrodictions. Testable predictions are not predictions about how organisms will evolve in the future. Instead, they refer to predictions about what we would expect to see in the fossil records or DNA, for instance, if evolution were true.

On the other hand, retrodictions are observations that make sense only in light of the evolutionary theory. In his book Why Evolution is True, biologist Jerry Coyne illustrates this through the vestigial tail in humans. The fishlike tail usually disappears in embryonic stages, but when it does not, a human is born with a tail projecting from the base of his spine.

A remnant of our ancestral species, tails can be still be seen in some of our close cousins, such as chimpanzees. The presence of a vestigial tail in humans can be rationalized only under the evolutionary theory and fails to make sense under a creationist model.

In the same book, Coyne presents a grand example of a testable prediction to support evolution: There were no terrestrial vertebrates until 390 million years ago, but clearly, they existed around 360 million years ago. Evolutionary theory, then, would predict the existence of a transitional form around this time period.

As expected, such a fossil from that exact time period was found in 2004 in Canada. It features traits corresponding to both fish and amphibians, including limbs that can be best described as part fin, part leg, Coyne writes.

Despite the overwhelming evidence in the fossil record, it is not uncommon to hear creationists demand for the missing links. A missing link refers to a fossil of an ancestral species that split into two different species through a process known as speciation. To begin with, the chances of finding fossils of a specific ancestral species nearly zero. Moreover, the transitional fossils provide the needed evidence.

Corpses fossilize under highly select conditions, and it is not only unreasonable but also illogical to expect fossils from every ancestral species. As Dawkins cleverly notes in his book The God Delusion, it is the equivalent of expecting a full cinematic record of a murderers every step leading up to the crime in order to convict him.

Even without the fossil record, evidence for evolution can be seen in DNA sequences, geographical distribution of species, bad design and so on.

If you were not already convinced of the veracity of the evolutionary theory, I do not expect you to nor should you change your mind in a few paragraphs. I have presented only a smattering of evidence for evolution, and the intention was only to illustrate the type of factual, unassailable and frankly, beautiful evidence that supports the evolutionary theory.

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OPINION Sastry: Evolution supported by extensive evidence - The Daily Toreador (registration)