Cambrian explosion
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The Cambrian explosion was an apparent burst of organic activity observed in the fossil record of the Cambrian period ca. 530 million years ago. It included the appearance of major organisms and the diversification of older ones. There are many potential reasons for why this event occurred and science in general has still not yet reached a full consensus[1] however several theories have been espoused including rising oxygen levels and the development of new molecular features that allowed more rapid evolution. It has also been contended that the explosion is an artefact of the fossil record, with the ancestors of Cambrian fauna not being preserved, leading to the appearance of a sudden burst of speciation.
[edit] In creationist claims
Creationists identify the Cambrian explosion as evidence of the unsoundness of the theory of evolution. The Jehovah's Witness publication Life--How did it get here? By evolution or by creation? refers to the Cambrian explosion in order to support its claim that the fossil record does not provide evidence of evolution:[2]
Thus, at the start of what is called the Cambrian period, the fossil record takes an unexplained dramatic turn. A great variety of fully developed, complex sea creatures, many with hard outer shells, appear so suddenly that this time is often called an "explosion" of living things.
This claim fails to recognize several aspects of the Cambrian explosion. The "explosion" took place over many millions of years and therefore was not as sudden as the claim in Life implies. Additionally, as noted above the precursors to Cambrian life were soft-bodied and did not leave many fossils. Nevertheless, there is in fact direct and indirect evidence of pre-Cambrian life in the fossil record. Thus the claim fails to utilize the Cambrian explosion in order to refute the theory of evolution.
[edit] Footnotes
- ↑ But we're pretty damned sure it wasn't a global flood that did it
- ↑ Life--How did it get here? By evolution or by creation?, Watchtower Bible and Tract Society of New York, Inc., Brooklyn, NY, 1985, p. 60
