On 23/01/2009, at 11:07 AM, Rceeberger quoted: > Earlier this year, research revealed that the rise and fall of > species on > Earth seems to be driven by the undulating motions of our solar > system as it > travels through the Milky Way. Some scientists believe that this > cosmic > force may offer the answer to some of the biggest questions in our > Earth's > biological history-especially where evolution has fallen short.
*sigh* "We've still got some questions" doesn't mean "fallen short". Is it me, or has the standard of science journalism in mainstream media plummeted over the last few years? It certainly has at the UK broadsheets. > > > Researchers at the University of California, Berkeley found that > marine > fossil records show that biodiversity increases and decreases based > on a > 62-million-year cycle. At least two of the Earth's great mass > extinctions-the Permian extinction 250 million years ago and the > Ordovician > extinction about 450 million years ago-correspond with peaks of this > cycle, > which can't be explained by evolutionary theory. ...because it doesn't explain external influences. > > > Earlier this year, a team of researchers at the University of Kansas > came up > with an out-of-this-world explanation for the phenomenon. Their idea > hinges > upon the fact that stars move through space and sometimes rush > headlong > through galaxies, or approach closely enough to cause a brief cosmic > tryst. This part isn't new at all. I heard of this notion at least 10 years ago, probably a lot earlier. It was hypothesised that a long-term cycle disturbs the Oort Cloud and Kuiper Belt, and more collisions out there leads to a lot more cometary stuff falling in to the inner solar system, leading to increased impact frequencies. Yes, it's a new spin on the proposed mechanism, but the idea that extinction events are influenced on a long-term cycle by galactic rotation or the transit of the solar system isn't new at all. It's interesting, but I'm really sick of the "evolution can't explain this" schtick. Evolution explains how diversity occurs. Extinction events are known, some are understood. That we don't know the specific causes of certain extinction events says nothing at all about evolutionary theory. Charlie. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
