Hi guys, I found this excellent video about The Cambrian Explosion on youtube.
PART I http://www.youtube.com/watch?v=qKMKYd0WSV0
PART II http://www.youtube.com/watch?v=PPkSMTQc8Cw
The Cambrian Explosion relates to an abrupt appearance of a wide range of organisms, mainly invertebrates, with hard (fossilizable) parts in Cambrian strata, which mainstream scientists date from about 540 million years ago. They were complex, well-developed organisms with many types of differentiated cells, and it is widely conceded that evolution of these organisms from unicellular precursors within such a short period of time is highly doubtful.
Now, it can be granted that organisms without skeletons will leave few if any fossils, so it should not be too surprising if one evolving line were to appear suddenly in the fossil record. It is surprising, however -- at least within an evolutionary framework -- that such a wide variety of fossilizable forms should appear at more or less the same time. The number of radically different body plans which appear in such a very short period of geological time (about 13 million years according to mainstream science) is greater than at any other. Accounting for the abrupt and sudden appearance of these organisms is one of the leading challenges in evolutionary biology.
http://www.pbs.org/wgbh/evolution/library/03/4/l_034_02.html
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