The two most influential men of the nineteenth century were born just hours apart on February 12, 1809. One, the American politician Abraham Lincoln, annually receives the bulk of attention on that date here in the U. S., which is understandable. His birthday mate, the British-born scientist Charles Darwin, launched what is arguably the most far-reaching intellectual revolution in history, but he remains scandalously maligned among large parts of the American public. Surveys consistently show that more than half of our population doesn’t think evolution happens. As Natalie Angier, a prominent science writer, puts it, Darwinism is “the national blood sport.”
Darwin’s great book of 1859, On the Origin of Species, sets forth in detail his theory of evolution by natural selection. He didn’t pretend to know how earth gave birth to life itself. Instead, he assembled a mass of solid evidence and inspired deduction to explain the path the earliest organisms took to develop and expand into the untold millions of complex species that followed. Before Darwin, humans attributed the process solely to a supernatural designer. His argument has stood the test of time, with enormous consequences in natural history, genetics, medicine, and philosophy. No thinking, literate person today would try to dispute the fact of evolution. So what’s the problem?
Just plain ignorance? Many people who have never taken the trouble to learn anything about literature, art, or science, reflexively object to new developments in those fields. This sort of hostility surfaced on the Origin’s publication in 1859. But one hopes that by now the nay-sayers would have familiarized themselves with some of the compelling evidence for evolution. Apparently not.
Religious grounds? Yes, Virginia, some people still think the world is only 6,000 years old, just as some still insist the earth is flat, but the evidence in rock strata doesn’t lie. To quote again from Angier (one of my favorite writers), “You can’t pull Bugs Bunny from a billion-year-old hat, and pterodactyls never tugged on Raquel Welch’s thong.” Evolution itself will eventually weed out those folks. On the other hand, many religious leaders embrace the occurrence of natural selection-though, like the Pope, they may insist that God inserted a soul in our first human ancestor at the moment he/she evolved from hominids. (Which leaves open the possibility he/she was born of soulless parents!)
Squeamishness? Some can’t bear to acknowledge their kinship with apes. Well, they might pursue their ancestors into deeper time and come up with a more acceptable link. How about a trilobite, or a single-celled creature? They too share our DNA, but without the nasty habits common to apes and us.
Simple misunderstanding? For instance, I’ve heard the complaint, “Our existence can’t be just a matter of chance!” But natural selection, evolution’s chief driving force, isn’t a random event. It’s a two-step process, the first randomly recombining the parents’ genes in the offspring, the second deterministic when the offspring interacts with its environment. As the evolutionary biologist Ernst Mayr wrote, “The first step consists in the production of an immense amount of new genetic variation, while the second step is the nonrandom retention (survival) of a few of the new genetic variants.”
Confusion? “Darwinism is just a theory,” some critics say. They have confused the words hypothesis and theory. A hypothesis is a supposition, a tentative description, still untested, around which a scientist attempts to build a case. A theory is a body of facts pulled together into a coherent whole that explains a part of our world.
Modern science has answered, since 1859, all of the major critiques and quibbles of the Origin. That isn’t to say that Darwinism is written in stone, like some alternative explanations of life on earth. Evolutionary biology is a dynamic science, an ongoing research program, tested and retested in each new generation, reworked as new evidence comes to light. But no one can look on the earth in the same way that our ancestors did before this great theory exploded like a bomb into a presumably secure culture. Darwin told it like it is, and the world has not been the same since.
One might say that, if Darwin had not evolved, God would have had to invent him.