Last Woolly Mammoths Originated in North America
Well isn’t that a kick in the pants when it seems at first Mammoths and humans crossed the ice bridge between Siberia and Alaska populating North America with the Wooly Mammoth, then as the sea receded the North American Wooly Mammoth and it is assumed North Americans went back to Siberia to populate the declining Siberian Wooly Mammoth population.
September 4, 2008
Genetic sleuthing finds last woolly mammoths originated in North America
By Bob Weber, THE CANADIAN PRESS
It's a standard image from any museum or textbook on early humans - skin-clad hunters brandishing stone-tipped spears and surrounding that icon of the Ice Age, an enormous but soon-to-be-supper woolly mammoth.
Now, DNA analysis has shed new light on the development of humanity's original full-meal deal. In a paper published Thursday in the journal Cell Biology, two Canadian scientists describe how they used genetic sleuthing to determine the last of the now-extinct beasts that fed humans around the world tens of thousands of years ago actually developed in North America.
"The Siberian mammoth went extinct about 38,000 years ago and they were supplanted by immigrants from North America," said Dr. Hendrik Poinar, an evolutionary geneticist from McMaster University in Hamilton, Ont. Close relatives of modern-day elephants, mammoths were huge, shaggy animals weighing up to eight tonnes.
They had curved ivory tusks that arced up to five metres on either side of their long, flexible trunks. The last ones died out about 4,000 years ago on Russia's Wrangel Island just northwest of the Bering Strait.
But in their prime, woolly mammoths ranged from Spain to North America in populations that may have reached up to sixty animals per 100 square kilometres in parts of Siberia.
They were so common that ivory from their tusks is still found and used in jewelry. That abundance - and their vulnerability to clever mammals able to hunt in groups - gave the animals a long association with human development.
As far back as 1.8 million years, early mammoths were being eaten by Homo erectus, the first hominid known to have used both tools and fire.
Until now, scientists believed that all types of mammoths developed in the Old World and that North America played only a minor role in their history. Poinar's research on the remains of 160 different animals paints a more complex picture.
Mammoths first crossed from Siberia to what is now Alaska and northern Canada hundreds of millennia ago on a land bridge across the Bering Strait.
It was created by falling sea levels during an ancient ice age. When the ice finally receded some 200,000 years ago, so did the bridge.
Siberian and North American mammoths were isolated from each other for the next 160,000 years, when the land link between the continents re-emerged during another ice age.
But this time it was the North American animals that crossed, replacing the declining herds of Siberian mammoths.