March 9, 2010


Philosophers Rip Darwin (Michael Ruse, 3/07/10, Rge Chronicle Review)

Last year was the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of his book, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. The anniversary was marked by conferences the world over. I will not tell you how many I attended; ecologically sensitive readers of The Chronicle might start whining about carbon footprints and that sort of thing. Let me just say that I found myself going no fewer than three times through the Quad City International Airport, in Moline, Ill. Moline!

I mention this as background to the publication of a new book by Jerry A. Fodor, a professor of philosophy at Rutgers University, and Massimo Piattelli-Palmarini, a professor of cognitive science at the University of Arizona. The title of the book, What Darwin Got Wrong (Farrar, Straus and Giroux), tells you their opinion of the old English naturalist and of his theory of evolution through natural selection. If Fodor and Piattelli-Palmarini were an isolated case, one could dismiss their book with a grimace (if you were a biologist), or welcome them with a cheer (if you were a creationist). But in the philosophical community, there is an increasingly vocal cadre of eminent philosophers harboring doubts about Darwin. To understand their critique, we must first put the clock back a year, to the beginning of the celebrations.

The anniversary conferences usually had a smattering of professional Darwin types like me—I am a historian and philosopher of science specializing in evolutionary theory—but the bulk of the presenters and attendees were evolutionary biologists. For two reasons, the atmosphere was universally positive. First, scientists deeply respect Darwin and his achievements. These people are evolutionists—they take the past seriously. Second, there was not a person at these conferences who was not excited about the science today. Evolutionary biology is on a roll, and that was a cause for celebration—and frenetic presentations that jammed in as much new science as possible. Moreover, to a person, the scientists saw that the first point led smoothly into the second. Everyone appreciates the tools of Darwinism, above all the mechanism of natural selection. But great science doesn't stand still. It picks up and carries ideas and findings way beyond the wildest hopes of its founders. Evolutionary biology today is deeply Darwinian, but it has outpaced the Origin in ways that its author could never have imagined. To use a hackneyed phrase, Darwin gave biology a paradigm, and biologists have been expanding it ever since.

Here is some of the work I heard about. This is important for what I have to say in this essay. Peter and Rosemary Grant, emeritus professors of biology at Princeton University, have for many years been tracking and studying the finches of the Galápagos archipelago. The Grants have recently become more interested in speciation, when groups pull apart and set up reproductive barriers.

Birth of New Species Witnessed by Scientists (Brandon Keim, November 16, 2009, Wired)
On one of the Galapagos islands whose finches shaped the theories of a young Charles Darwin, biologists have witnessed that elusive moment when a single species splits in two.

In many ways, the split followed predictable patterns, requiring a hybrid newcomer who’d already taken baby steps down a new evolutionary path. But playing an unexpected part was chance, and the newcomer singing his own special song.

This miniature evolutionary saga is described in a paper published Monday in the Proceedings of the National Academy of Sciences. It’s authored by Peter and Rosemary Grant, a husband-and-wife team who have spent much of the last 36 years studying a group of bird species known collectively as Darwin’s finches. [...]

No exact rule exists for deciding when a group of animals constitutes a separate species. That question “is rarely if ever asked,” as speciation isn’t something that scientists have been fortunate enough to watch at the precise moment of divergence, except in bacteria and other simple creatures. But after at least three generations of reproductive isolation, the Grants felt comfortable in designating the new lineage as an incipient species.

The future of the species is far from certain. It’s possible that they’ll be out-competed by other finches on the island. Their initial gene pool may contain flaws that will be magnified with time. A chance disaster could wipe them out. The birds might even return to the fold of their parent species, and merge with them through interbreeding.

It would not matter that Darwinism is bad philosophy if it were good science, but to cliing to an evil ideology in the face of the evidence is a serious matter.

Posted by Orrin Judd at March 9, 2010 7:07 PM
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