Natural Selection

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The idea of natural selection is frequently misunderstood, and even ignored when people discuss evolutionary science. This prevents any understanding of evolution.

Yet it has been described as the greatest idea that has ever occurred to a human mind. Huxley, Darwin's friend, when he first came to understand it declared, "How extremely stupid not to have thought of that!"

"Origin" was published in 1859. People today have had more than enough time to learn about it and understand it, but here I am, in 2022, having to explain it to some people. They are without excuse.

People caricature the principle of natural selection, either by ignorance, or as dishonest propaganda tactic, as being a supposed mysterious force which is doing the selection, for which there is no evidence. Or they ignore it completely, straw-manning evolution as the supposed results of "pure chance".

Darwin and Wallace were contemporaries, but each of them hit on the idea of natural selection independently. They were trying to figure out how and why the forms of living organisms could change over generations. Darwin noted that humans selectively bred their animals and plants. As part of his investigations, he made an extensive investigation, among other things, of the activities of "pigeon fanciers" who bred extreme variants of pigeons just for pleasure and for competition. It was known as "artificial selection" or selective breeding. This had been going on for as long as humans have had control of plants and animals, and even control of other humans. We select for traits or qualities that suit our purpose, be it for better yields of food, for aesthetics, or for any other desired qualities. Artificial selection, applied to humans, is eugenics. The Spartans, and no doubt other peoples, practiced eugenics. Shaka, the Zulu warrior king, would not permit his fighters to marry until they had killed an enemy in battle. Eugenics continues today in the subtle form of arranged marriages, class and racial prejudice and personal mate choice. Darwin, BTW, was opposed to the eugenic practices proposed by his cousin, Francis Galton.

"The aid which we feel impelled to give to the helpless is mainly an incidental result of the instinct of sympathy, which was originally acquired as part of the social instincts, but subsequently rendered, in the manner previously indicated, more tender and more widely diffused. Nor could we check our sympathy, if so urged by hard reason, without deterioration in the noblest part of our nature." - Charles Darwin, The Descent of Man

It's almost as if he saw the depravity of the extreme right and Nazism coming.

Darwin and Wallace proposed that something that had a similar effect to artificial selection, shaping and changing the forms of living things, was operating in nature. It was not some mysterious force, but it had a similar effect to artificial selection, with certain heritable variations quite naturally being more successful than others in getting themselves reproduced. It is thus a metaphor. They did not understand the actual mechanisms of variation and heredity, but that makes it all the more remarkable that they identified the overall principle. "How extremely stupid not to have thought of that!" Isn't hindsight wonderful? The mechanisms were discovered, and are understood in great detail today. It is a supreme vindication of their ideas.

One last thing. Selection works at the level of the gene. It is not a matter of different species or "races" or individuals fighting tooth and claw. Your genes descend from two parents, and theirs from two each, and so on. Your offspring, if you produce them, will have half your genes, and half your mate's genes. They will dilute their genes further in further generations. I often think of it as being like an hourglass. The sand particles pass through the narrow neck and that is you, very briefly. It is each of your "sand particle" genes that are, separately, tested by natural selection as the generations continue.