the evolving mind

In a sense, without evolution there would be no agricultural industry, no livestock farming. Many if not most of the original, “natural” forms of our animal and vegetable food sources are paltry versions of what exist today. What changed them? Call it guided evolution.

In his book, The Greatest Show on Earth: The Evidence for Evolution, Richard Dawkins devotes two chapters to how, for centuries, human beings have been agents of selection (“Dogs, Cows and Cabbages” and “The Primrose Path to Macro-Evolution”). He writes,

“Darwin’s special genius realized that nature could play the role of selecting agent.”

Dawkins sagely recognizes, however, that the line we draw between “natural selection” and human (unnatural) selection is spurious. Whether selection is intentional (i.e., breeders selecting rock doves–pigeons–for coloration) or unintentional (birds with stronger bills better surviving in times of drought…see The Beak of the Finch: A Story of Evolution in Our Time) — to the organism in question it really doesn’t matter.

If we bother to look around us, we would see that evolution is happening all the time. Okay, maybe not in terms of obvious morphological changes. But in terms of the ebb and flow of gene prevalence in a given population. Yes, ebb and flow. Only with a misunderstanding of evolution can one extract “progress” from it. Many important genetic changes could be described as “one step forward, the same step back.” A good example is human immunity. Our immune systems are constantly changing. Some might say “to stay one step ahead of viruses and parasites.” I would say to be able to side-step the forms we are likely to encounter in our current environment. And that’s what counts. That’s all that counts. In terms of natural selection.

Because the small steps of evolution occur at the genetic level, they seem invisible. That many species continue to change but ultimately “stand still”–according to our perspective–means that evolution can be tough to detect in real time. And, as Dawkins points out, variation among the offspring of specific members of a population is greater than the variation among generations of that population. It’s the nature of the evolution beast. So to speak.

Back to intentional selection. Dawkins’ recent book brought me a a true insight. Because he puts it so well, I’ll quote him verbatim.

“Artificial selection is not just an analogy for natural selection. Artificial selection constitutes a true experimental – as opposed to observational – test of the hypothesis that selection causes evolutionary change.”

I can see that. Thanks Richard.

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