Monday, August 29, 2005

According to the Talk.Origins Archive, sharks haven't changed because they "are excellently adapted to their particular niche in their environment."
Does anyone know how this "excellent adaptation" was measured
(apart from observing that sharks haven't changed, that is)?

"[T]he geological record features episodes of high dying, during which extinction-prone groups are more likely to disappear, leaving extinction-resistant groups as life's legacy."
S.J. Gould & N. Eldredge, "Punctuated equilibrium comes of age", Nature (1993) 366:223-7, p. 225.
Anyone wants to tell me how this "extinction-proneness" was measured, except by noting that the groups went extinct?

Or what about this one by grand old man Mayr, trying to explain why things like the giant antlers of the "Irish Elk" and the canines of saber-toothed "tigers" aren't problematic for Darwinism:
"All these features would seem, at first sight, to be highly deleterious, and it was claimed
that natural selection could not possibly have favored or even tolerated their evolution. However, the studies of Rensch, Simpson, Gould, and various other paleontologists have demonstrated that the species that had these "excessive" characters always flourished for considerable periods of time when these characters clearly were of selective advantage and that their ultimate extinction coincided with a climatic or broad faunal change which simultaneously led to the extinction of nummerous other species without such `excessive' characters."
E. Mayr, Toward a New Philosophy of Biology: Observations of an Evolutionist
, (Harvard University Press, 1988), p. 250.
These species "flourished", so their structures must have been favored by selection after all? Well, glad we got that cleared up.

Saturday, August 20, 2005

Image test