Proof of Evolution

When pious people pray and what they pray for comes to pass they sometimes cite this happy circumstance as proof that God exists and answers prayer. If what they pray for doesn't happen they still sometimes insist that God exists and answers prayer but that his answer in this case was "no."

Skeptics scoff at this. They argue, understandably, that you can't use the conjunction of a prayer and the realization of the hoped for outcome as confirmation of God's existence if you refuse to accept the conjunction of prayer and the failure to realize the hoped for outcome as a disconfirmation of God's existence.

This imperviousness to falsifiability, we're told, is what makes religion inferior to science as a means of discovering the truth about things. Science does not permit the sorts of evasions illustrated by the above example. Unless, that is, the scientific topic is evolution. When evolution is at issue science often becomes indistinguishable from religion.

Consider a recent story in the Washington Post about a study of bacteria found off the coast of Australia:

Far beneath the ocean’s surface, buried in a layer of murky sludge, communities of ancient bacteria have existed virtually unchanged for nearly half of Earth’s history. In what researchers call the “greatest absence of evolution ever reported,” these deep-sea creatures have taken a pass on the chaos of biological progress for the past 2.3 billion years.

A study published this week in the Proceedings of the National Academy of Sciences said these communities offer evidence of “extreme evolutionary stasis” — a total lack of evolution in response to a lack of change in the surrounding environment. Populated by sulfur-cycling bacteria that derive energy from processing dissolved sulfate in the surrounding water, the communities were found in nearly identical forms at two distinct points in the fossil record and still exist today.

“The microbes we see in the fossils are almost identical to what we see in the ocean now,” study co-author Malcolm Walter, a professor of astrobiology at the University of New South Wales, told The Washington Post in a telephone interview. “They have similar shapes and are doing similar chemistry.”

But the fact these particular organisms successfully avoided evolving for billions of years doesn’t disprove the theory of evolution — quite the opposite.

Darwin’s theory states that species evolve through natural selection in response to environmental changes — increased threats from predators, new competition from other animals, changes in access to water or air. But the inverse is also true: If there is no change in the environment of a balanced ecosystem, the organisms that constitute it should remain similarly unchanged — a principle dubbed evolution’s “null hypothesis.”

But how do the study's authors know that the ocean environment has been stable for billions of years? How do they know there haven't been subtle physical and chemical changes in the habitat of these bacterial organisms? After all, other creatures in the same marine environment have apparently evolved. It seems that we're being told that we can know the environment has been stable because the bacteria haven't changed and the bacteria haven't changed because their environment has been stable.

This not only has about it a whiff of circularity, it also happens not to be true that evolution only responds to changes in the environment. Evolution, according to theory, can occur whether the environment changes or not, purely through genetic drift.

Anyway, the article goes on:

“These microorganisms are well-adapted to their simple, very stable physical and biological environment,” the study’s lead author, University of California at Los Angeles professor William Schopf, said in a university press release. “If they were in an environment that did not change but they nevertheless evolved, that would have shown that our understanding of Darwinian evolution was seriously flawed.”

So, If organisms change over time that's strong evidence of evolution, and if they don't change at all throughout the entire history of life on earth, well, that's also evidence for evolution. This sounds a bit like a religious person insisting that if he gets what he prays for that's evidence that God exists, and if he doesn't get what he prays for that's also evidence that God exists.

Who says scientists aren't religious?