The Burgess Shale fossil bed in Canada provided a treasure trove of fossils from the Cambrian Period. Over a time course of about 10 to 20 million years many modern and fossil animal phyla came into existence and no new phyla developed after that. Over 90% of the species became extinct while others formed the beginnings of multiple modern phyla including chordates from which vertebrates including man evolved. The mechanisms by which the incredible burst of creation and diversity of body forms could have developed so quickly are discussed in the next.
Evolution is not directed
In reflecting on the wonders of the Burgess Shale [Cambrian] fossils, Gould mused in A Wonderful Life that if the tape of time were rewound and the period of the Burgess Shale replayed, the animals who survived and those who became extinct might be totally different and all subsequent life forms could have been different. The point and truth of this mental exercise is that as much as it may appear to have been goal directed toward a magnificent outcome (man) each step of the way was a crap-shoot of random events. The outcome of evolution is not predetermined.
