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.

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.

It has been argued that dinosaurs did not die out, but just evolved wings and flew away. At a certain level, this reasoning is sound.... Birds, as a group, did descend from dinosaurs and ... all 8,600 species of birds living today carry some inheritance from their reptilian ancestors.

There are millions of different species of animals and plants on earth--possibly as many as forty million. But somewhere between five and fifty BILLION species have existed at one time or another. Thus, only about one in a thousand species is still alive--a truly lousy survival record: 99.9 percent failure!

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.

A new theory is guilty until proven innocent, and the pre-existing theory innocent until proven guilty ... Continental drift was guilty until proven innocent.

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.