Evolution as a Fact

It is heartening to see that so many scientists and philosophers wrote letters to New York Times, responding to Nicholas Wade's review of Dawkins's book, in which he said that evolution is not a "fact" as claimed by Dawkins. [I had also posted that review sometime back on my blog, in which, i admit, i had described it as a 'balanced review', which perhaps only reveals that the issue of distinction between theory and fact can get quite confusing at times.] These letters can be found here and here. I'll be posting some extracts below:

* "If geologists had to confront a similar propaganda campaign against plate tectonics, they would get a little testy too, I imagine, and physicists might grow impatient if they had to devote half their professional time and energy to fending off claims that quantum mechanics is the work of the devil."

Daniel Dennet, author of “Breaking the Spell” and “Darwin’s Dangerous Idea.

"The crucial point is that, as Dawkins appreciates, the distinction between theory and fact, in philosophical discussions as in everyday speech, can be drawn in two quite distinct ways. On the one hand, theories are conceived as general systems for explanation and prediction, while facts are specific reports about local events and processes. On the other hand, “theory” is used to suggest that there is room for reasonable doubt, whereas “fact” suggests something so amply confirmed by the evidence that it may be accepted without debate.

Opponents of evolution slide from supposing that evolution is a theory, in the first sense, to concluding that it is (only) a theory, in the second. Any such inference is fallacious, in that many systematic approaches to domains of natural phenomena — like the understanding of chemical reactions in terms of atoms and molecules, and the study of heredity in terms of nucleic acids — are so well supported that they count as facts (in the second sense). Many scientists and philosophers who have written about evolution have pointed out that the contemporary theory that descends from Darwin has the same status — it, too, should count as a “fact.” Dawkins is entirely justified in following them."

Philip Kitcher, John Dewey professor of philosophy at Columbia University

* "Evolution is a fact, natural selection is a process and Darwin’s theory is that the fact is explained by the process. The facts of evolution are as evident as any facts about the past can be. So is the fact that blind variation and natural selection can produce a lot of adaptational change. Darwin’s theory about how it does so is indeed a work in progress, but one whose basic correctness is no more open to doubt that General Relativity."

Alex Rosenberg, R. Taylor Cole professor of philosophy at Duke University.

* "In his review “The Greatest Show on Earth,” Nicholas Wade erred by insisting that because evolution is a theory, it cannot also be a fact. Actually, evolution is both. Darwin marshaled a convincing body of evidence for the fact of evolution. He also theorized a process, natural selection, to explain how evolution occurs. All great scientific theories have these two components: evidence revealing patterns in nature, and hypothesized natural processes that explain those patterns."

Mark A. Schlessman, Professor of biology at Vassar College

* "The confusion concerns Dawkins’s correct claim that it is misleading to refer to the thesis that the species evolved as “just a theory.” Like the Copernican theory, the theory of evolution is a theory to be sure, but it is also a theory now known to be factually correct. It is a fact, a known fact, that the earth revolves around the sun and that the species evolved. Theories about the mechanics of how evolution occurs are, as Wade points, still being debated and are not yet complete. But Dawkins is not denying this."

Ed Erwin, Professor of philosophy at the University of Miami.

* "Dawkins is referring to the overwhelming physical evidence of biological evolution — both fossil evidence and molecular evidence — as “fact,” which as far as scientific facts go, is as firm a fact as any. It is the mechanism of evolution that is still not completely understood, and attempts to describe this mechanism are “theories of evolution.”"

Peter C. Rowson, Stanford Linear Accelerator Center

* "Of course both claims are correct. The analogy in physics is that the gravitational force exists as a fact, whereas the theory explaining the gravitational force evolved over time from Newton’s view to that of Einstein, and is now accepted to be Einstein’s General Theory of Relativity. In a similar manner, the evolution of life is a fact, whereas the theory explaining the evolution of life is Darwin’s theory of evolution by natural selection. Unfortunately, Darwin’s theory of natural selection is often called the theory of evolution, leading to unnecessary confusion with the fact of the evolution of life."

Larry Woolf, Principal optical scientist and program manager at General Atomics in San Diego, Calif.

* "By the “fact” of evolution, biologists mean that all of the animals, plants and bacteria that are now alive, or have ever lived, have a common ancestor that was alive over a billion years ago. This claim is beyond dispute among biologists. We will never understand all of the various mechanisms that have resulted in evolution but there is no evidence that casts the slightest shadow of doubt over the fact of evolution. The biochemistry, DNA inheritance and cell biology of all living things point indisputably to a common ancestor. That is the “fact” of evolution, and it should not be confused, as Wade seems to have done, with the theory of how we got here from that common ancestor."

Lewis Greenwald, Associate professor in the Department of Evolution, Ecology and Organismal Biology at the Ohio State University.