Friday, July 27, 2007

Science and Unexamined Philosophical Baggage

A quotation for the weekend:
Scientists sometimes deceive themselves into thinking that philosophical ideas are only, at best, decorations or parasitic commentaries on the hard, objective triumphs of science, and that they themselves are immune to the confusions that philosophers devote their lives to dissolving. But there is no such thing as philosophy-free science, there is only science whose philosophical baggage is taken on board without examination. Daniel Dennett, Darwin's Dangerous Idea, 1995, p.21.

Well put. Too bad Dennett is not more aware of, and honest about, his own philosophical baggage.

More on philosophy and worldviews here and here.

There are more posts on Daniel Dennett on this blog (since he will always be "the original" Darwinan Fundamentalist) and you can find them by searching by his name in the search box at the top of this page.

Thursday, July 26, 2007

Gradualism and Macroevolutionary Theory

For some time now I have wanted to juxtapose these quotations:

Richard Dawkins on the importance of gradualism for the plausibility of macroevolutionary theory:
Evolution is very possibly not, in actual fact, always gradual. But it must be gradual when it is being used to explain the coming into existence of complicated, apparently designed objects, like eyes. For if it is not gradual in these cases, it ceases to have any explanatory power at all. Without gradualness in these cases, we are back to miracle, which is simply a synonym for the total absence of explanation. Dawkins, R. (1995) River Out of Eden, Basic Books, New York, p. 83.

Stephen J. Gould on stasis and sudden appearance in the fossil record:
The history of most fossil species includes two features particularly inconsistent with gradualism: 1. Stasis. Most species exhibit no directional change during their tenure on earth. They appear in the fossil record looking much the same as when they disappear; morphological change is usually limited and directionless. 2. Sudden appearance. In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and "fully formed." (Gould, Stephen J., "Evolution's Erratic Pace," Natural History, Vol. 86, No. 5, May 1977, p.14).

Now I am sure that some readers will cry "quote-mining" as soon as they read this. So let me say for the record that Gould and Dawkins each have their ways of explaining why the fossil record is, in fact, consistent with macroevolutonary theory. However, their explanations differ significantly, and I do not find either one fully convincing.

More importantly, I wish to point out that I am submitting these quotations for the simple purpose of showing that the fossil record, taken as a whole, has features that pose problems for macroevolutionary theory. There is no scientific consensus on how to resolve those problems.

This information should not be suppressed, and should be presented to students.