Don't tell Al Gore that!
Posted on 10/12/2006 1:51:19 PM PDT by neverdem
If rodents in Spain are any guide, periodic changes in Earth’s orbit may account for the apparent regularity with which new species of mammals emerge and then go extinct, scientists are reporting today.
It so happens, the paleontologists say, that variations in the course Earth travels around the Sun and in the tilt of its axis are associated with episodes of global cooling. Their new research on the fossil record shows that the cyclical pattern of these phenomena corresponds to species turnover in rodents and probably other mammal groups as well.
In a report appearing today in the journal Nature, Dutch and Spanish scientists led by Jan A. van Dam of Utrecht University in the Netherlands say the “astronomical hypothesis for species turnover provides a crucial missing piece in the puzzle of mammal species- and genus-level evolution.”
In addition, the researchers write, the hypothesis “offers a plausible explanation for the characteristic duration of more or less 2.5 million years of the mean species life span in mammals.”
Dr. van Dam and his colleagues studied the fossil record of rats, mice and other rodents over the last 22 million years in central Spain. The fossils are numerous and show a largely uninterrupted record of the rise and fall of individual species. Other scientists say rodents, thanks to their large numbers, are commonly used in studies of such evolutionary transitions.
As the scientists pored over some 80,000 isolated molars, the most distinct markers of different species, the patterns of turnovers emerged. They seemed often to occur in clusters, which seemed unrelated to biology.
--snip--
The longer-term cycle, the scientists determined, peaks when Earth’s orbit is closer to being a perfect circle.
--snip--
The “pulses of turnover,” the scientists determined, occurred mainly at times when the different cycles left Earth a colder world.
(Excerpt) Read more at nytimes.com ...
still Bush's fault...
Maybe if we launch all the socalist into space. Just a thought.
It is NOT!!! It's Rove's fault! He didn't make Hurricane Katrina strong enough!
Don't tell Al Gore that!
"tilt of its axis are associated with episodes of global cooling."
Someone better tell Al Gore that.
Human caused global warming should be encouraged then!!
Whad ya trying to do...give big Al Gore the socialist who invented the Internet a heart attack or something. heh heh.
Hmmmm from the position of the Sun and facing Earth, does it tilt to the Right or to the Left?
Already posted, and,
Milankovitch Cycles.
We're all gonna die!!!!!!!!!!!!!
Sheesh. The Tennessee 2 x 4's blood pressure must've shot up on that news.
Had a show on the science channel the other night about how the Moon affected the Earth's climate in the past, not to mention what it still does today. I mean, it only affects the motion of the waves. No big deal. It is also theorized to affect the release of the Earth's energy resulting in volcanic eruptions and earthquakes. Maybe the treehuggers would like to blow up the Moon and see what that does to our way of life.
Climate Change, on the other hand, is a result of axis tilt and orbital rhythmetrics, (sounds like an '80s disco duo!)
Perform an internet search for "Milankovich cycles".
Nope, soon it will be 'man made global tilt'. And the US will be framed as having the most obese people, because of its wealth, and needs to redistribute it to other countries to even out the weight balance.
1000 'scientists' will sign a document making a consensus that there is no doubt.
I heard that the Dec. 2004 tsunami caused the earth to wobble on its axis and changed the rotation.
ping
Isn't it amazing how this long article manages to avoid mentioning any possible connection between recent global warming and this very non-man-made phenomenon?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.