« CBS in Los Angeles Tells Ghost Stories as News
Main
Don't Pee in Your Laptop, At Least not Yet »
August 15, 2005
The Truth About the Cambrian Explosion
If you're interested in the significance of the Cambrian 'explosion,' PZ Myers at Pharyngula offers a great summary of the current state of the science.
My summary of his summary: There are fossils and trace fossils of phosphatized embryos, soft-bodied and multicellular animals and bilaterally symmetric animals from roughly 570-600 million years ago. All those life forms come from more than 50 million years before the Cambrian period. In the approximately 50 million year period between this early "Vindian" period and the Cambrian we begin to see fossils of small shelly critters. All this is still before the Cambrian! PZ has lots of great illustrations and links to other articles.
So the stage is set for the Cambrian explosion. Starting with the stock of pre-Cambrian life forms most of the modern phyla developed in the Cambrian. But they are far from the forms we see around us today. And while this happened somewhat rapidly in geological terms, it still took tens of millions of years.
PZ want us to learn three lessons:
- The Cambrian 'explosion' was real"
- "While this was a sudden event in a geological sense, it wasn't actually all that rapid in human terms. "
- Creationist, including Intelligent Design creationists, are wrong when they try to use the Cambrian explosion as proof for a designer "since the data certainly does not fit a sudden creation by divine or alien fiat. It does fit with the idea of the appearance of these animals as a product of prior history. . . "
Go read the whole story at Pharyngula
Posted by Duane Smith at August 15, 2005 7:34 PM | Read more on Evolution |
Trackback Pings
TrackBack URL for this entry:
http://www.telecomtally.com/mt/mt-tb.cgi/1312