Researchers studied DNA preserved in Arctic permafrost sediments and in the remains of such ancient animals to unravel the mystery behind extinction of ice age mammals.
The Ice Age ended about 10,000 years ago. Ancient animals that survived during the ice age relied heavily on the protein-rich wildflowers, forbs. The plant was present everywhere in the region that time, but when the climate began to become warmer again after the ice age these flowers started to decay. As a result, the Arctic was left with cover of grasses and shrubs without the same nutritional value. The big herbivorous animals could not sustain their survival on those plants, said researchers.
Scientists reported in the journal Nature on Wednesday that the change in vegetation approximately started 25,000 years ago and ended about 10,000 years ago.
Scientists have been endeavoring for years to figure out what actually led to their mass extinction after many blamed human beings for causing the mass extinction of the big animals by hunting them.
Scientists studied the 242 permafrost sediment samples from various Arctic sites and the feces and stomach contents from the mummified remains of Ice Age animals.
It was found that a kind of plant known as forbs dominated the entire region. Forbs are kind of essential wildflowers very rich in protein. As early vegans depended heavily on the flowers as a vital source of protein, their disappearance after the ice age led to extinction of mammoths and many animals.
"The whole Arctic ecosystem looked extremely different from today. You can imagine these enormous steppes with no trees, no shrubs, but dominated by these small flowering plants", said Eske Willerslev of the University of Copenhagen, an expert in ancient DNA.