Siberian Mammoth died out 40,000 years ago

[Andre]

apparently, and was replaced by the American mammoth, That's the result of mitochondrial DNA research:

http://www.msnbc.msn.com/id/26545527/

There is something with that excellent picture of the Yarkov mammoth mummy, heavy copyright fights.



I hope this is the right place to post it.

 

[turbo]

Very interesting!

 

[Andre]

Indeed it is, Turbo

Sorry I made two errors with the Yarkov mammoth, first of all it is spelled Jarkov Mammoth, secondly, In reality it's the Yukagir mammoth that was on the Expo in Japan

Take note here:

As to what led to this continental-level decline, "there is a very large unknown looming here," MacPhee said. He does not think competition between the different mammoth populations is a likely culprit. Human over-hunting also does not make sense.

"You have humans in both Asia and North America at that time, but no drop-out in North America at that time," he added. "Disease of course immediately comes to mind, but we have nothing to go on for that yet."

What time exactly. The only time discussed is 40,000 years ago. Where is DrPaleo?

 

[turbo]

It's not feasible to use over-hunting to explain the collapse of a sub-species if their ranges overlapped and/or if they were subjected to similar hunting pressures in different regions. If they had different herd behaviors or perhaps were concentrated in different regions (where the ranges overlapped) it is possible to consider that a change in hunting strategy might have wiped out a population. If you could panic adults or somehow cut young mammoths out of herds (easier prey) it might have been possible to cause the collapse of entire herds. Little ones could be killed more easily, but they would also have to have been culled more frequently than adults to supply the same amount of meat. The long (I assume, comparing to elephants) time required for maturation would have given the mammoths limited time to replenish their population with breeding adults, if the young ones were being killed efficiently. Probably a bogus idea, but it's worth a thought. After all, African plains predators preferentially attack the young, the weak, and the sick - the prolific breeding and fast maturation of antelopes, gazelles, etc, allows them to stay in balance with their predators. If humans came up with some tactics that gave them an edge in this prey-predator relationship, mammoths with slow reproductive/replacement rates might not have been able to cope.

 

[Andre]

Mammoths and men have coexisted in many parts of the world for thousands of years and the overkill hypothesis is only associated with N-America, nowhere else. STill the stone tools and fluted points were found on more places like the Solutrean culture in France, around 20,000 years ago, while the Mammoths lasted there until about 15,000 (calendar) years ago . Therefore, the essential part in the hypothesis is the new arrival of the Clovis encountering naive mega fauna that had not learned to fear men.

This shows a completely different picture.

 

[hypatia]

This really does make me think of disease rather then over hunting. Mainly because the area of land is so great. But turbo has given me much food for thought. Now all we need to know is the population of both man and mammoth in that area, 40,000 years ago.

 

[Andre]

Why would it need to have a disaster? Most 'extinctions' are due to better competitors taking over the niche. Perhaps that allochtone females from America had enough edge for some reason to outperform their Siberian competitors. For the casual observer nothing needed to have happen, the amount of mammoths staying more or less the same but the better families taking over.

 

[Andre]

meanwhile got the original article,

Debruyne et al., Out of America: Ancient DNA Evidence for a New World Origin of Late Quaternary Woolly Mammoths, Current Biology (2008), doi:10.1016/j.cub.2008.07.061

Summary

Although the iconic mammoth of the Late Pleistocene, the woolly mammoth (Mammuthus primigenius), has traditionally been regarded as the end point of a single anagenetically evolving lineage, recent paleontological and molecular studies have shown that successive allopatric speciation events must have occurred within Pleistocene Mammuthus in Asia, with subsequent expansion and hybridization between nominal taxa [1, 2]. However, the role of North American mammoth populations in these events has not been adequately explored from an ancient-DNA standpoint. To undertake this task, we analyzed mtDNA from a large data set consisting of mammoth samples from across Holarctica (n = 160) and representing most of radiocarbon time. Our evidence shows that, during the terminal Pleistocene, haplotypes originating in and characteristic of New World populations replaced or succeeded those endemic to Asia and western Beringia. Also, during the Last Glacial Maximum, mammoth populations do not appear to have suffered an overall decline in diversity, despite differing responses on either side of the Bering land bridge. In summary, the ‘‘Out-of-America’’ hypothesis holds that the dispersal of North American woolly mammoths into other parts of Holarctica created major phylogeographic structuring within Mammuthus primigenius populations, shaping the last phase of their evolutionary history before their demise.

edit: added:

http://www.lbl.gov/Science-Articles/Archive/NSD-mammoth-extinction.html

Richard Firestone, the father of the big comet hypothesis assumes that it was the supernova that did it.

 

[baywax]

Andre... I don't know if you've seen this but it is bringing new significance to the North American Mammoth!

Last woolly mammoths had North American roots: study
Last Updated: Thursday, September 4, 2008 | 12:20 PM ET Comments26Recommend26
CBC News
The last of the woolly mammoths to roam the Earth had North American ancestry, according to a study released Thursday by researchers at McMaster University in Hamilton.

The study, based on DNA of woolly mammoth specimens, is expected to cause some controversy among paleontologists, because it suggests that North American mammoths replaced their Eurasian counterparts. The study appears in the September issue of Current Biology.

Hendrik Poinar, associate professor in the departments of anthropology, and pathology and molecular medicine at McMaster University, said the results of the study are surprising.

"Scientists have always thought that because mammoths roamed such a huge territory, from western Europe to central North America, that North American woolly mammoths were a sideshow of no particular significance to the evolution of the species," he said.

"However, it now appears that mammoths established themselves in North America much earlier than presumed, then migrated back to Siberia, and eventually replaced all pre-existing haplotypes of mammoths."

Poinar said migrations over Beringia, the land bridge that once spanned the Bering Strait, were rare. "It served as a filter to keep eastern and western groups or populations of woollies apart," he said.

DNA evidence reveals ancestry

But the study shows that a migration of North American mammoths did occur. Woolly mammoths lived between 40,000 and 4,000 years ago.

Poinar and Regis Debruyne, a post-doctoral research fellow in Poinar's lab, spent three years collecting and sampling mammoths from much of their former range in Siberia and North America. They extracted DNA and pieced together the samples, comparing and studying hundreds of mammoth specimens using a database of ancient DNA.

Debruyne said the study shows that North American mammoths were more important in evolutionary terms than previously considered by scientists.

"Like paleontologists, molecular biologists have long been operating under a geographic bias," he said.

"For more than a century, any discussion on the woolly mammoth has primarily focused on the well-studied Eurasian mammoths. Little attention was dedicated to the North American samples, and it was generally assumed their contribution to the evolutionary history of the species was negligible. This study certainly proves otherwise."

http://www.cbc.ca/technology/story/2008/09/04/woolly-mammoths.html