Perhaps the only thing that saves science from invalid conventional wisdom that becomes effectively permanent is the presence of mavericks in every generation - people who keep challenging convention and thinking up new ideas for the sheer hell of it or from an innate contrariness.

The charge that the construction of the geologic scale involves circularity has a certain amount of validity. ...Thus, the procedure is far from ideal and the geologic ranges are constantly being revised (usually extended) as new occurrences are found.

I doubt if there is any single individual within the scientific community who could cope with the full range of [creationist] arguments without the help of an army of consultants in special fields.

Now let me step back from the problem and very generally discuss natural selection and what we know about it. I think it is safe to say that we know for sure that natural selection, as a process, does work. There is a mountain of experimental and observational evidence, much of it predating genetics, which shows that natural selection as a biological process works.

In the beginning, there were bacteria.... [A] nearly universal assumption is that all subsequent life descended from the original life form through a continuous chain of ancestor-descendant pairs. This assumption looks good because all living organisms share biochemical traits. It is conceivable, of course, that life originated more than once on the early earth but that all except one life form died out early, leaving a single lineage as the ancestor of life as we know it. If this did happen, it was the first important species extinction.

250,000 species of plants and animals recorded and deposited in museums throughout the world did not support the gradual unfolding hoped for by Darwin.

The once rather old-fashioned science of paleontology finds itself in a maelstrom of excitement and controversy. Astrophysicists, atmospheric scientists, geochemists, geophysicists, and statisticians are all contributing to the extinction problem. And the general public is taking part through television talk shows, magazine cover stories, newspaper editorials, and even the occasional mention in gossip columns.