It is embarrassing that surveys show that most Americans do not believe in evolution, and do believe in scientifically unsupportable concepts that they have seen in the movies, like dinosaurs and humans living together. The great American Museum of Natural History in New York has always done what it could to combat this sort of ignorance, with a magnificent standing display of dinosaurs. It is now putting on a big exhibition entirely devoted to Charles Darwin, the man who revealed that natural selection and descent with modification were the ways that life on Earth worked. (This is not to neglect Alfred Russel Wallace, who deserves to be better known as the co-discoverer of evolution. It was his discovery of the same principles that made Darwin finally reveal his own decades of thought on the matter, and the papers of the two discoverers were simultaneously published. Darwin, however, published more on the subject, dug into it more deeply, and did his own researches that have made his contributions preeminent.) The curator of the exhibition, Niles Eldredge, is famous on his own for advocating (along with the late Stephen Jay Gould) a modern modification of Darwinism, punctuated equilibrium. For those who cannot get to the exhibition, or who wish to spend more than an afternoon absorbing its ideas, Eldredge has written _Darwin: Discovering the Tree of Life_ (Norton). There are, deservedly, much bigger books that serve as biographies of this great thinker who was in many ways a completely admirable scientist and human being. The book has a basic short account of Darwin's life, but was written to give a history of the internal thought underlying Darwin's big ideas. Eldredge has gone back to the notebooks to trace inceptions, rather that to summarize the findings that were eventually published in the epochal _On the Origin of Species_ for an invigorating look at how this model scientist came to believe as he did.
Eldredge makes clear from the beginning that Darwin was up against religious orthodoxy. The greatest religious barriers he had to overcome were his own. Time and again, Darwin confronted creationist ideas but found simpler and more reasonable ones in the natural world. In his researches, starting with the voyage of the _Beagle_, he was confounded by trying to figure out the mind of God. Why, for instance, was God extinguishing some species and creating others when he could have gotten it all right in the first place? To ask such questions was not to give an unflattering picture of the capabilities of the designer, but to seek if there were not a better, more natural explanation. Eldredge takes us through the notebooks, showing the intuitive and creative leaps Darwin made, for instance, upon encountering the writings of Thomas Malthus. Before that, though, his fieldwork had convinced him that species were not immutable but rather gave rise to one another. Darwin's ideas, in retrospect, look exceedingly simple (and his friend and advocate Thomas Huxley wondered why they had taken so long for anyone to see). He didn't get everything right, but the confirmations of his overall thought continue to pour in. Evolution is a testable notion, and has passed so many rigorous tests that it is extremely unlikely that it will be overthrown in the future.
That won't keep people from trying. It is significant that there are really only religious rather than scientific objections to evolution, even if religious objections are sometimes dressed up in scientific garb. Eldredge's last chapter, wittily titled "Darwin as Anti-Christ", reviews the religious objections. Mainstream Protestants, Catholics, and Jews have had little problem with the concept of evolution. Christian fundamentalists adhere to the literal account, Eldredge says, because they must not succumb to doubt over any section of the literal Bible and because if we are "descended from monkeys" (always the phrase used by those ignorant of real descent) we will for some reason not be able to lead moral lives. It is no surprise that Eldredge finds such arguments unconvincing, but he spends several pages explaining the problems of creationism's new clothes, Intelligent Design. Darwin's ideas are testable, have been tested, and have prevailed. The Intelligent Design advocates have found a conveniently untestable proposition, for basic scientific rules insist we would have to use our senses to gain evidence of the supernatural, which just isn't done; and if the design force isn't supernatural, then the first step must be to demonstrate that it naturally exists. However, Eldredge's well-illustrated book is not a polemic. Those who are looking for a basic explanation of Darwin's ideas, and how they came to him, and how he eventually told the world of them, will enjoy this book immensely.