Latest Study Blames Climate Changes for the Demise of Woolly Mammoths

A recent study has found evidence that adds to the theory that climatic changes led to the extinction of woolly mammoths.   

The researchers found two periods of a big population shakeup of the mammoths, both of them occurring in 'interglacials,' or periods between ice ages.

A study team from Sweden and Britain analyzed and examined DNA samples from 300 specimens of woolly mammoths spanning a period of 200,000 years found across North America and Europe. They were able to find their migration patterns and could figure out the number of mammoths that lived at a given point of time.

They observed the genetic diversity of the specimens and found that lesser diversity in the samples pointed to a smaller population.

"The picture that seems to be emerging is that they were a fairly dynamic species that went through local extinctions, expansions and migrations. It is quite exciting that so much was going on," said Dr. Love Dalen of the Swedish Museum of Natural History, in an interview to  BBC News.

Researchers said that the species depleted and split  about 120,000 years ago when the world heated up for a short while. The fall in the population of the towering tuskers is estimated to be from several millions to tens of thousands but the figures improved as Earth entered another ice age called the Late Pleistocene.

When the Earth entered another warmer phase, the species' numbers again dropped. They were confined to small pockets of habitat suitable to them, a cold arid climate.

Some scientists believe that humans had a hand in making them extinct as they were hunted down. But another school believes that the mammoth intruded into warmer habitable climates of humans and hence, were killed.

"Spells of warm climate made the mammoth more susceptible to extinction," said Dr. Dalen, according to AFP.

But further studies are needed to determine why the mammoths went extinct. Evidence of their survival can be traced to two places in Alaska and Siberia as recently as 5,000 years ago.