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Mehrdad
02-06-2014, 07:33 PM
I used to think that disease and over hunting led to the extinction of the large ice age mammals in the America's. Apparently a new theory (http://news.yahoo.com/disappearance-wildflowers-may-doomed-ice-age-giants-231025081.html) is suggesting that the disappearance of wildflowers could have been the reason for this extinction.

Joe B
02-07-2014, 01:50 AM
I used to think that disease and over hunting led to the extinction of the large ice age mammals in the America's. Apparently a new theory (http://news.yahoo.com/disappearance-wildflowers-may-doomed-ice-age-giants-231025081.html) is suggesting that the disappearance of wildflowers could have been the reason for this extinction.
Thanks Mehrdad

The Quaternary extinction event is puzzling. Wildflower disappearance may be part of the story. Most likey it was a number of reasons. I like this qoute from the Yahoo/Reuters article.

"We think that the major driver (of the mass extinction) is not the humans," Eske Willerslev said, although he did not rule out that human hunters may have delivered the coup de grace to some species already diminished by the dwindling food supplies.

Fifty thousand years of Arctic vegetation and megafaunal diet
http://www.nature.com/nature/journal/v506/n7486/full/nature12921.html
This is the Editor's summary from Nature

The picture is a familiar one in reconstructions of the Late Quaternary in the far north of Eurasia: abundant mammoths and other now extinct megafauna grazing on grassy 'mammoth steppe' tundra. Analyses of the vegetation of this period have been based mainly on fossil pollen data. This study uses a more direct approach — the analysis of plant and nematode DNA from sites all around the Arctic — and the results paint a rather different picture, questioning the predominance of grasses and suggesting that grass dominance may not be necessary to sustain a diverse megafauna. Before about 10,000 years ago the vegetation contained many protein-rich forbs — herby plants that are not graminoids (grasses, reeds and sedges) — that would have played a large part in supporting this diverse northern ecosystem. After the Last Glacial Maximum, however, the woody plants and graminoids dominated. The authors conclude that megafauna such as woolly mammoth, woolly rhinoceros, bison and horse may have been opportunistic mixed-feeders rather than grass specialists.
The sample location map (http://www.nature.com/nature/journal/v506/n7486/fig_tab/nature12921_F1.html) show that the study was limited to the artic. They did not address megafauna south of the glaciated areas.
IMO The Quaternary extinction is still a mystery.