Posted on 08/09/2005 9:14:38 AM PDT by jb6
The ancient sabretooth is not directly related to modern day cats, according to a new DNA analysis.
Large cats such as the sabretooth roamed North and South America toward the end of the last Ice Age, around 13,000 years ago.
The puma, also known as a mountain lion or cougar, and the jaguar are the only remaining large cats in the Western Hemisphere.
Paleontologists have closely studied the extinct American cats based on their bone structure, but the proposed relationships remain contentious.
To refine the branches of the feline family tree, Ross Barnett of the Henry Wellcome Ancient Biomolecules Centre in Oxford and his colleagues from Britain, Sweden, the Canadian Museum of Nature in Ottawa, the U.S. and Australia compared DNA from three large cats to modern members of the cat family.
The researchers examined specimens of a sabretooth cat from Patagonia, a related scimitartoothed cat from the Yukon and a cheetah-like cat called Miracinonyx trumani.
"Our results show that the sabretooths diverge early and are not closely related to any living cats," the team concludes in the Aug. 9 issue of the journal Current Biology.
Another cat that resembles a cheetah, called Miracinonyx, is actually a relative of today's puma, the researchers said.
Scientists have proposed that cheetahs started out in the New World, but the analysis of mitochondrial DNA and fossil data points to their origins in the Old World.
The study's authors suggest Miracinonyx evolved long limbs and large nostrils suited "to excel in high-speed pursuit" of its antelope prey in the Midwest, just as modern cheetahs are built for chasing in the African savannah.
The feline family tree split into its Miracinonyx and puma branches as the prairie grassland grew in North America, the team notes.
Here's one for you...if you're still out there.
Viking Kitties soon to respond.
It depends on the timeframe you are considering. Ultimately, all large mammals came from Asia! The other night on Discovery (I think), a program traced the evolution of mammals based on the fossils that have been discovered.
When the dinosaurs were wiped out 65 million years ago, giant flightless birds (i.e., over 6 feet tall) with huge beaks became the dominant predator everywhere but in Asia (which was then cut off from the rest of the continents by ice). Mammals remained small except in Asia, probably because the birds ate the big ones. It took about 20 million years for the mammals in Asia to diversify and get large, and for mammal carnavores to arise.
Then the earth got warm, and land bridges to the other continents opened up. Within a short period of time, the giant birds became extinct, probably because the mammal carnavores ate them. Mammals then became the dominant life form everywhere for the next 45 million years.
Unless G-d created these fossils just to mess with our minds.
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New Insight Into Horse Evolution
BBC | Saturday, 2 July, 2005 | Helen Briggs
Posted on 07/03/2005 2:03:06 AM PDT by nickcarraway
http://www.freerepublic.com/focus/f-news/1435663/posts
"...Ultimately, all large mammals came from Asia..."
As I understand it, camelids originated in the new world and migrated into the old.
Clarification: The program asserted that large mammals originated in Asia from 65 million years ago until about 45 million years ago, then migrated out. That leaves 45 million years to have additional migrations back and forth when land bridges existed.
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