Sunday, January 2, 2011

Some stuff I stole from Jerry Coyne's Why Evolution is True

If all creationists could somehow be forced to read Why Evolution is True by Jerry Coyne there would be no more creationists.

These quotes were stolen from Jerry Coyne's book and from his blog. Please buy his book. My apologies to Jerry Coyne of the University of Chicago for stealing priceless quotes from your masterpiece Why Evolution is True.

If anything is absolutely, rock-bottom true, it’s that life evolved, beginning about 4 billion years ago, and that the creation myth of Genesis is completely wrong.

Even without fossils, we have evidence of human evolution from comparative anatomy, embryology, our vestigial traits, and even biogeography. We've learned of our fishlike embryos, our dead genes, our transitory fetal coat of hair, and our poor design, all testifying to our origins. The fossil record is really the icing on the cake.

natural selection: The nonrandom, differential reproduction of alleles from one generation to the next. This usually results from the carriers of some alleles being better able to survive or reproduce in their environments than the carriers of alternative alleles.

If the history of science teaches us anything, it is that what conquers our ignorance is research, not giving up and attributing our ignorance to the miraculous work of a creator.

But, as Lovan noted in his piece, “83 percent of home-schooling parents want to give their children ‘religious or moral instruction.’” I weep for those children. For many of them are simply being brainwashed by their parents. Yes, that’s what it is—brainwashing. For a parent to ignore 150 years of solid science, feeding their children lies based on theology, is to deprive those children of the wonder of the universe—a wonder based on truth rather than medieval superstition. It kills off the part of a child that most needs nurturing: her sense of wonder, and all the possibilities of life that are opened up by that wonder. How many budding biologists have been stifled by their parents’ willful ignorance of science, and on their insistence that the Bible is the real source of biological information? Generation after generation of ignorance and religious dogmatism, all perpetuated by religously based home-schooling.

Chance alone cannot explain the marvelous fit between individuals and their environment. And it doesn't. True, the raw materials for evolution--the variations between individuals--are indeed produced by chance mutations. These mutations occur willy-nilly, regardless of whether they are good or bad for the individual. But it is the filtering of that variation by natural selection that produces adaptations, and natural selection is manifestly not random. It is a powerful molding force, accumulating genes that have a greater chance of being passed on to others, and in so doing making individuals even better able to cope with their environment. It is, then, the unique combination of mutation and selection--chance and lawfulness--that tells us how organisms become adapted.

Over the past quarter-century, poll after poll has revealed that nearly half of all Americans flatly reject evolution, many clinging to the ancient superstition that the earth was created only 6,000 years ago, complete with all existing species. But as Richard Dawkins shows in his splendid new book, The Greatest Show on Earth, the theory of evolution is supported by at least as much evidence as is the germ theory of disease--heaps of it, and from many areas of biology. So why is it contemptible to reject germ theory but socially acceptable to reject evolutionary theory?

Since Dart's time, paleoanthropologists, geneticists, and molecular biologists have used fossils and DNA sequences to establish our place in the tree of evolution. We are apes descended from other apes, and our closest cousin is the chimpanzee, whose ancestors diverged from our own several million years ago in Africa. These are indisputable facts. And rather than diminishing our humanity, they should produce satisfaction and wonder, for they connect us to all organisms, the living and the dead.

But not everyone sees it that way. Among those reluctant to accept Darwinism, human evolution forms the core of their resistance. It doesn't seem so hard to accept that mammals evolved from reptiles, or land animals from fish. We just can't bring ourselves to acknowledge that, just like every other species, we too evolved from an ancestor that was very different. We've always perceived ourselves as somehow standing apart from the rest of nature. Encouraged by the religious belief that humans were the special object of creation, as well as by a natural solipsism that accompanies a self-conscious brain, we resist the evolutionary lesson that, like other animals, we are contingent products of the blind and mindless process of natural selection. And because of the hegemony of fundamentalist religion in the United States, this country has been among the most resistant to the fact of human evolution.

When dealing with the human fossil record, creationists go through extreme, indeed almost humorous, contortions to avoid admitting the obvious. In fact, they'd prefer to steer clear of the issue. But when forced to confront it, they simply sort hominin fossils into what they see as two discrete groups--humans and apes--and assert that these groups are separated by a large and unbridgeable gap. This reflects their religiously based view that although some species may have evolved from others, humans did not, but were the object of a special act of creation. But the whole folly is exposed by the fact that creationists can't agree on exactly which fossils are "human" and which are "ape". Specimens of H. habilis and H. erectus, for example, are classified as "apes" by some creationists and "humans" by others. One author has even described a H. erectusspecimen as an ape in one of his books and a human in another! Nothing shows the intermediacy of these fossils better than the inability of creationists to classify them consistently.

Every day, hundreds of observations and experiments pour into the hopper of scientific literature. Many of them don't have much to do with evolution--they're observations about details of physiology, biochemistry, development, and so on--but many of them do. And every fact that has something to do with evolution confirms its truth. Every fossil that we find, every DNA molecule that we sequence, every organ system that we dissect supports the idea that species evolved from common ancestors. Despite innumerable possible observations that could prove evolution untrue, we don't have a single one. We don't find mammals in the Precambrian rocks, humans in the same layers as dinosaurs, or any other fossils out of evolutionary order. DNA sequencing supports the evolutionary relationships of species originally deduced from the fossil record. And, as natural selection predicts, we find no species with adaptations that benefit only a different species. We do find dead genes and vestigial organs, incomprehensible under the idea of special creation. Despite a million chances to be wrong, evolution always comes up right. That is as close as we can get to a scientific truth.

But even without fossils we'd still know something about our place on the tree of evolution. As Linnaeus proposed, our anatomy places us in the order Primates along with monkeys, apes, and lemurs, all sharing traits such as forward-facing eyes, fingernails, color vision, and opposable thumbs. Other features put us in the smaller superfamily Hominoides along with the "lesser apes" (gibbons) and "great apes" (chimpanzees, gorillas, orangutans, and ourselves). And within the Hominidae, sharing unique features like flattened fingernails, thirty-two teeth, enlarged ovaries, and prolonged parental care. These shared characters show that our common ancestor with the great apes lived more recently than our common ancestor with any other mammal.

Molecular data derived from DNA and protein sequences confirms these relationships, and also tells us roughly when we diverged from our relatives. We are most closely related to the chimpanzees--equally to the common chimp and the bonobo--and we diverged from our joint common ancestor about seven million years ago. The gorilla is a slightly more distant relative, and orangutans more distant yet (12 million years since the common ancestor).

Evolutionary theory, then, makes predictions that are bold and clear. Darwin spent some twenty years amassing evidence for his theory before publishingThe Origin. That was more than a hundred and fifty years ago. So much knowledge has accumulated since then! So many more fossils found; so many more species collected and their distributions mapped around the world; so much more work in uncovering the evolutionary relationships of different species. And whole new branches of science, undreamt of by Darwin, have arisen, including molecular biology and systematics, the study of how organisms are related.

And we'll see, all the evidence -- both old and new -- leads ineluctably to the conclusion that evolution is true.

I certainly make no claim to be the Milton of Darwinism. But I can at least try to dispel the misconceptions that frighten people away from evolution and from the amazing derivation of life's staggering diversity from a single naked replicating molecule. The biggest of these misconceptions is that accepting evolution will somehow sunder our society, wreck our morality, impel us to behave like beasts, and spawn a new generation of Hitlers and Stalins.

That just won't happen, as we know from the many European countries whose residents wholly embrace evolution yet manage to remain civilized. Evolution is neither moral nor immoral. It just is, and we make of it what we will. I have tried to show that two things we can make of it are that it's simple and it's marvelous. And far from constricting our actions, the study of evolution can liberate our minds. Human beings may be only one small twig on the vast branching tree of evolution, but we're a very special animal. As natural selection forged our brains, it opened up for us whole new worlds. We have learned how to improve our lives immeasurably over those of our ancestors, who were plagued by disease, discomfort, and a constant search for food. We can fly above the tallest mountain, dive deep below the sea, and even travel to other planets. We make symphonies, poems, and books to fulfill our aesthetic passions and emotional needs. No other species has accomplished anything remotely similar.

But there is something even more wondrous. We are the one creature to whom natural selection has bequeathed a brain complex enough to comprehend the laws that govern the universe. And we should be proud that we are the only species that has figured out how we came to be.

In fact, understanding evolution should surely deepen and enrich our appreciation of the living world and our place in it. The truth -- that we, like lions, redwoods, and frogs, all resulted from the slow replacement of one gene by another, each step conferring a tiny reproductive advantage -- is surely more satisfying than the myth that we were suddenly called into being from nothing.

We also harbor dead genes that came from other species, namely viruses. Some, called 'endogenous retroviruses' (ERVs), can make copies of their genome and insert them into the DNA of species they infect. (HIV is a retrovirus.) If the viruses infect the cells that make sperm and eggs, they can be passed on to future generations. The human genome contains thousands of such viruses, nearly all of them rendered harmless by mutations. They are the remnants of ancient infections. But some of these remnants sit in exactly the same location on the chromosomes of humans and chimpanzees. These were surely viruses that infected our common ancestor and were passed on to both descendants. Since there is almost no chance of viruses inserting themselves independently at exactly the same spot in two species, this points strongly to common ancestry.

Creationists often cite Haeckel's "fudged" drawings as a tool for attacking evolution in general: evolutionists, they claim, will distort the facts to support a misguided Darwinism. But the Haeckel story is not so simple. Haeckel may not have been guilty of malfeasance, but only of sloppiness: his "fraud" consisted solely of illustrating three different embryos using the same woodcut. When called to account, he admitted the error and corrected it. There's simply no evidence that he consciously distorted the appearance of embryos to make them look more similar than they already were.

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