No –unlike the woolly mammoth, the woolly rhinoceros and for instance the giant deer– the tundra beauties in the picture [Penn State handout] above are not extinct. That’s because they managed to flee to central northern Canada and the northern margins of Greenland. But in their long journey to escape rising temperatures and flying arrow heads – something in the musk ox population did die: intraspecific biodiversity – a term we hope you recall.
This an international research group of 55 scientists from various universities, with a large Danish contingent and led by the University of Copenhagen, concludes in their Nature publication, which was released yesterday.
Next to the mammoth, woolly rhino and musk ox, they have investigated the faith of three other large mammals that were part of the ice age megafauna, but got into trouble at the dawn of Holocene: wild horse, the reindeer and the bison. That did not happen during previous interglacial periods, like the Eemian [which may even have been somewhat milder], but started somewhere 18,000 years ago, after the end of the actual ice age, and before the Younger Dryas.
This shows the tundra creatures could withstand a little warming – as long as that nasty army of homo sapiens killers didn’t cut off their escape route to the north.
“Although these cold-adapted animals certainly fared better during the colder, glacial periods, they still managed to find places where the climate was just right – refugia – so that they could survive during the warmer, interglacial periods. Then, after the peak of the last ice age their luck started to run out,” explaines Beth Shapiro, of Pennsylvania State University.
“The question is what changed? Why were these mammals no longer able to find safe refugia where they could survive in a warm climate?”
To get to answers the researchers collected (fossil) DNA material from the 6 ice age mammals. From this they conclude the extinction of the woolly rhinoceros was in Europe probably down the climate change itself (as much of the habitats did not overlap), but the extinction of mammoth and wild horse was greatly helped about by human hunting.
Besides, the genetic biodiversity within bison, reindeer and musk ox populations decreased – probably too because of synergetic damage of climate change and another environmental stressor: us.
Thus it seems like the end of the Holocene will have something in common with its start – isn’t there beauty in such harmony.
© Rolf Schuttenhelm | www.bitsofscience.org