Another Big Bang for Biology

By Phil Berardelli
ScienceNOW Daily News
3 January 2008

Researchers have uncovered what they think is a sudden diversification of life at least 30 million years before the Cambrian period, the time when most of the major living groups of animals emerged. If confirmed, the find reinforces the idea that major evolutionary innovations occurred in bursts.


The main points of Charles Darwin's theory of evolution, which he carefully laid out in The Origin of Species 149 years ago, have stood the test of time. But where Darwin assumed that natural selection proceeds slowly and orderly--much the way Isaac Newton imagined a clockwork universe--modern investigations have shown that the process more resembles the chaotic world of quantum physics. Scores of new groups of species can appear within a few million years. By far the biggest and most famous of these events is the Cambrian explosion, a period between 542 million and 520 million years ago, when due to some still-unknown cause, the ancestors of nearly all extant groups, or phyla, of animals appeared.

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