Quotes About Phyla

The idea was to study fertilization in as many different phyla and organisms as possible, using the simplest possible equipment and a microscope. Biochemical approaches were not much in vogue, and running gels impossible at first.

Some fifteen to twenty Burgess species cannot be allied with any known group, and should probably be classified as separate phyla. Magnify some of them beyond the few centimeters of their actual size, and you are on the set of a science-fiction film...

with the Darwinian view for yet another reason. The Chengjiang discoveries intensify the top-down pattern of appearance in which individual representatives of the higher taxonomic categories (phyla, subphyla, and classes) appear and only later diversify into the lower taxonomic categories (families, genera, and species).

with clues that would seem to discredit him. Through his grouping of disparate body types into existing phyla and his ingenious version of the artifact hypothesis, Walcott had found an elegant way to explain all this seemingly uncooperative evidence in a Darwinian way.

In any case, the discovery in China of chordates, and other previously undiscovered phyla in the Cambrian, only accentuates the puzzling top-down pattern of appearance that other Cambrian discoveries had previously established.

The term "Cambrian explosion" was to become common coin, because Walcott's site suggested the geologically abrupt appearance of a menagerie of animals as various as any found in the gaudiest science fiction. During this explosion of fauna, representatives of about twenty of the roughly twenty-seven total phyla present in the known fossil record made their first appearance on earth (see Fig. 2.5).

FIGURE 2.8 According to Darwinian theory, the strata beneath the Cambrian rocks should evidence many ancestral and intermediate forms. Such forms have not been found for the vast majority of animal phyla. These anticipated but missing forms are represented by the gray circles. Lines and dark circles depict fossilized representatives of phyla that have been found.

So Popper's theory of knowledge is coterminous with a theory of evolution. Problem-solving is the primal activity: and the primal problem is survival. 'All organisms are con stantly, day and night, engaged in problem-solving; and so are all those evolutionary sequences of organisms - the phyla which begin with the most primitive forms and of which the now living organisms are the latest members.'2