Natural History

From UPI’s Science News:

A British study on the extinction of woolly mammoths found the last known population of the prehistoric animals did not die out because of inbreeding.

The study, conducted jointly by British and Swedish scientists, examined bones, teeth and tusks from Wrangel Island in the Arctic Ocean where the last known population of woolly mammoths lived about 4,000 years ago, the BBC reported.

Mammoths generally disappeared from mainland Eurasia and North America about 10,000 years ago, but lived on for another 6,000 years on Wrangel Island.

“Wrangel Island is not that big and it was initially thought that such a small population could have suffered problems of inbreeding and a lack of genetic diversity,” said the report’s co-author, Dr. Love Dalen of the department of molecular systematics at the Swedish Museum of Natural History.

Researchers found that, contrary to popular belief, the animals more likely were killed off by human activity or environmental factors.

The report, published Friday, concluded that the extinction of mammoths on Wrangel Island was “not a delayed outcome of an inevitable process” such as inbreeding.

“This suggests that the final extinction was caused by a rapid change in the mammoths’ environment, such as the arrival of humans or a change in climate, rather than a gradual decline in population size,” the study said.

The study also found the population of mammoths on the island generally ranged between 500 and 1,000.

Dalen said the study can be useful in modern-day conservation programs.

“What’s really interesting is that maintaining 500 effective individuals is a very common target in conservation programs,” he said. “Our results therefore support the idea that such an effective population size is enough to maintain genetic diversity for thousands of years. These mammoths did fine with what was originally considered to be a small number.

One should note that most dog breeds have far fewer than 500 effective individuals in their populations.

That should be a cause for concern, but one should realize that there are other measures of genetic diversity that need to be considered when making these conclusions.

Many people are not aware that mammoths actually did live into historic times, although in that part of the world written records from that time period are probably nonexistent.

But they were there.

And they were thriving.

Because their extinction is so late in time, it is possible that hunting pressure could have caused the extinction. However, there is no evidence that humans ever hunted these mammoths, so the most likely reason for their extinction is climate change.

There is a lot of debate about what cause the extinction of mammoths on mainland Eurasia and North America. Human overkill and climate change have been bandied about for decades.  And a third possibility, a combination of climate change and human hunting pressures, seems to be the current best-supported hypothesis. The mainland extinction was part of a much larger megafaunal extinction that happened at the end of the Pleistocene.

Of course, now we have mad scientists in Russia and South Korea who are going to clone a mammoth.  (But this project is much more difficult than one might realize).

But these cloned animals will always be  gimmick.

They will never be a self-sustaining population.

But it wasn’t that long ago that there was a healthy, genetically diverse, and sustainable population of mammoths.

Of course, on i09’s article on this same study, we have the obligatory creationist analysis in the comments section:

What’s even more mind-boggling is.. The Earth was completely different before the Great Flood with lots of creatures and animals that people in the world today either deny existed or refuse to believe could have existed.

They never give up, do they?

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