DNA study suggests hunting did not kill off mammoth

[muriel_volestrangler]

Researchers have found evidence to suggest that climate change, rather than humans, was the main factor that drove the woolly mammoth to extinction.
...
"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," he told BBC News.
...
They found that the species nearly went extinct 120,000 years ago when the world warmed up for a while. Numbers are thought to have dropped from several million to tens of thousands but numbers recovered as the planet entered another ice age.

The researchers also found that the decline that led to their eventual extinction began 20,000 years ago when the Ice Age was at its height, rather than 14,000 years ago when the world began to warm again as previously thought.

http://www.bbc.co.uk/news/science-environment-24034954

[Jackpine Radical]

1. Thanks for that piece.

Paleontology is one of my (far too numerous) interests.

[TheDeputy]

2. Not overly surprising

There were not that many people around back then.

[dimbear]

3. Still suspect humans, myself. Direwolf, Saber Tooth Cat, Mammoth all go extinct about the

same time near the appearance of humans.

[Thor_MN]

8. Predators, Prey.

Their fortunes are linked.

[NickB79]

4. Wait, that decline timeframe doesn't make sense

The DNA evidence shows they almost went extinct 120,000 yr ago, when the planet was in a warm interglacial period, but recovered as the planet cooled again.

However, it then says that the final extinction event began at the HEIGHT of the last glaciation, when you'd expect their populations to be strong and healthy.

It doesn't sound like their final extinction event was comparable to their previous near-miss, which then brings up the question: what was different 20,000 years ago compared to 120,000 years ago?

I can only think of human predation.

Also, we know that mammoths survived into fairly recent history despite the changing climate: the dwarf mammoths of Wrangel Island were possibly still alive when the Egyptian Pyramids were built.

http://www.bbc.co.uk/news/science-environment-17457561

They also showed no signs of inbreeding, which leaves only human interaction or further climate change as the final blow.

[muriel_volestrangler]

5. It suggests it was lack of grass

They speculate that it was so cold that the grass on which they fed became scarce. The decline was spurred on as the Ice Age ended, possibly because the grassland on which the creatures thrived was replaced by forests in the south and tundra in the north.

They had problems in both the coldest stages of a glaciation, and at the end.

Yes, the Wrangel Island ones survived thousands of years, but in a very special habitat, with different competitors (and in that oxymoronic 'dwarf mammoth' form).

[NickB79]

6. That makes some sense, but still seems lacking

The closely related mastodons, for example, lived in the forests that were replacing those grasslands, yet also went extinct.

The related Columbia mammoths lived much further south, in what is now California, yet also went extinct.

Also, WRT to the Wrangel Island mammoths, that island supported them for many millenia after the Ice Age ended, yet never warmed enough to support forests. The flora present today is largely the same that was present for the past 10,000 years, which is a tundra environment.

The Wrangel Island mammoths adapted to and survived quite well in an environment very similar to many millions of acres of tundra today across the northern hemisphere. I find the explanation given by the OP lacking because of this.

[Gov101]

7. Hmmm

I don't think the title of the article/thread fits with what the researchers are concluding. They aren't saying that hunting didn't kill off the mammoth, they just now have reason to believe that hunting wasn't the "principle" cause of the extinction.