The theory of evolution, Leshner announced to the students, was as firmly established as the theory of gravity. … Leshner grabbed a set of papers and books. If the theory of gravitation still held true, it predicted with very high probability that the bundle would fall.
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Evolutionary theory, Leshner explained, does the same thing. It explains and makes predictions about the living world that hold up. Even though Darwin’s theory predated — by a century — the discovery of DNA and a scientific understanding of the role of genes in heredity, the more science learns, the more the living world looks exactly like what would be expected if evolution were true. All living things are built from the same genetic toolbox, and species that evolution predicts are closely related share more genetic material than those that evolution says are far apart. Humans and chimps, for example, share 96 percent of their DNA sequence. Intelligent design’s argument that evolution cannot explain the origin of astoundingly complex biological systems such as the flagellum of bacteria — the microscopic, whiplike propulsion system with multiple interdependent parts — is indistinguishable, Leshner said, from the bland assertion that science has not explained everything. Unexplained, however, is not the same as unexplainable. When ID advocates see something unexplained, they point to the supernatural. But science, by definition, looks only for natural explanations, Leshner said.
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Crocker’s arguments are part of a familiar litany of half-truths and errors, said Alan Gishlick, a research affiliate at the National Center for Science Education. The Miller-Urey experiment was not intended to be evidence for evolution but part of a research program into how biological mechanisms might arise from nonbiological chemical reactions. As for gluing moths to trees, Gishlick said, researcher Kettlewell affixed the moths to trees to determine how birds spot moths of different hues. The photos were illustrations and never meant to be depictions of real life.
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While critics of evolution point to gaps in the fossil record — asking, for instance, why no fossils of intermediary species exist between land mammals and sea mammals — new discoveries regularly fill those holes. By 1994, observed Brown University biologist Ken Miller, scientists unearthed fossils of animals near the Indian subcontinent that had front and hind limbs capable of walking on land and flippering through water.
Why have such examples failed to convince doubters? Over many months of interviews about intelligent design, I gradually came to realize that evolution’s advocates and critics are mostly talking about different things. While the controversy over intelligent design is superficially about scientific facts, the real debate is more emotional. Evolution cuts to the heart of the belief that humans have a special place in creation. If all things in the living world exist solely because of evolutionary competition and natural selection, what room is left for the idea that humans are made in God’s image or for any morality beyond the naked requirements of survival? Beneath all the complex arguments of intelligent design advocates, Georgetown theologian John Haught agreed, “there lies a deeply human and passionately religious concern about whether the universe resides in the bosom of a loving, caring God or is instead perched over an abyss of ultimate meaninglessness.”
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Many religious conservatives believe the assertion that science and religion occupy separate, non-conflicting spheres is a smokescreen, a convenient way for religious liberals to brush conflict under the carpet. That may be why Leshner’s diplomatic views are rarely mentioned by critics of evolution. And it is also why a 64-year-old biologist in England has come to occupy an outsize role in one of America’s oldest culture wars. No matter the forum, location or theme, any debate about intelligent design or evolution will sooner or later invoke the name of Richard Dawkins.
“Anyone who chooses not to believe in evolution is ignorant, stupid or insane,” said Dawkins, professor of public understanding of science at Oxford University.
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Dawkins first shot to fame with his bestselling book, The Selfish Gene, published in 1975, which laid out the idea that animals — humans included — are essentially survival machines for genes. Individual animals die, and whole species may go extinct, but an unbroken genetic line connects every living thing on Earth. In the three decades since he wrote that book, Dawkins has seen his ideas become textbook orthodoxy, even as the notion of selfish genes has grown controversial among nonscientists. Even his wife, the biologist noted, once said, “Selfish genes are Frankensteins, and all life their monster.”
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Dawkins told me that the idea that science and religion occupy separate spheres doesn’t stand up to scrutiny. Every miracle in the Bible, from the Virgin Birth to the Resurrection, tramples on what Dawkins calls the scientific grass. “Politically, it’s expedient to pretend there is no conflict,” he told me. “What I care about is what’s true, not what’s politically expedient.”
And evolutionary science has a great deal to say about ethics and morality, Dawkins said. Being “pro-life in debates on abortion or stem cell research always means pro-human life, for no sensibly articulated reason,” he once wrote. The fact that humans think of themselves as altogether distinct from other animals — and the biblical notion that humans have dominion over other animals — is a sort of racism, Dawkins said. Evolution shows that fox hunters and bullfighters are tormenting their own distant cousins, which is why the biologist sends money to anti-bullfighting groups in Spain, and why he notes with pride that fox hunting was banned on the family farm. “The melancholy fact,” Dawkins wrote in an essay called “Gaps in the Mind,” “is that, at present, society’s moral attitudes rest almost entirely on the . . . speciesist imperative.”
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“I am a passionate Darwinian when it comes to explaining how things are, but I am an even more passionate anti-Darwinian when it comes to politics,” said Dawkins, who comes close to describing himself as a pacifist. “Let us understand Darwinism so we can walk in the opposite direction when it comes to setting up society.”