“Darwin’s Dilemma”: Was the Cambrian Explosion Too Fast For Evolution? | NCSE

Link: http://ncse.com/blog/2013/10/darwin-s-dilemma-was-cambrian-explosion-too-fast-evolution-0015109

In the "sudden appearance" of organisms during the geologically brief Cambrian explosion, creationists imagine tangible evidence for the supernatural creation of animal "kinds." To their eyes, these rocks record the moment of creation when Yahweh declared: "Let the land produce living creatures according to their kinds." They point to Precambrian rocks with their lack of fossilized hard parts, then point to Cambrian layers with their copious fossils and say, "See! Right there: creation." The story is not so simple, of course; we now know a lot more about life in the period before the Cambrian. The ancient lineages that eventually diversified extend far back in time, a long fuse leading to the eventual explosion.

While the rapid evolution during the Cambrian is described as geologically brief, it is important to define what that means. On human timescales, the shortest estimation for the length of the Cambrian explosion, about 10 million years, is incomprehensibly long. Moreover, the tiny Cambrian arthropods likely had much faster maturations and much shorter lifespans than humans. Our anthropocentric perception of the flow of time, in which a family might have only three or four generations per century, is very different from the number of generations Cambrian critters produced. Ten million years provides plentiful time, as Lee et al. showed. Yet creationists insist that there was not enough time for such biological complexity to arise, without ever defining why that time frame is insufficient.