Mammoths, surviving on an island between America and Eurasia, died of thirst – BBC

In the spring of 2015 at the State Natural Reserve and the candidate of geological sciences Sergey Vartanyan published an article in which he described, by killing the last mammoths lived on Earth. Today it is considered that the last population of woolly mammoths became extinct on Wrangel Island 4 thousand. Years ago, and Vartanian proved that ruined their inbreeding , which is increasingly resulting in mutations and deformities.

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However, prior to this isolated population of mammoths fought for survival on another piece of land -. St. Paul island, located almost midway between the Russian Far East and the coast of Alaska

Once this part of the land was the transition section that connected Eurasia and North America, but rising sea levels cut it from both continents, and made one of the most remote from the shores of the islands on the planet.

although the continental mammoths became extinct about 14-13,2 thousand. years ago, and their relatives from St. Paul island We were able to hold out a little longer. Deploy them was almost nowhere – the island area of ​​110 square meters. km is comparable to the area of ​​Paris or “Disneyland”, and how it was almost 8 thousand. years survived huge mammals, remains a mystery. However, scientists led by Graham Russell of the University of Pennsylvania in an article published in the journal PNAS , reported that this is the population died out – and, most importantly, why

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In 2004, researcher Dale leggings from the University of Alaska conducted radiocarbon analysis found on the island of mammoth tooth, which shows that the holder I lived about 7900 years ago. This was the first evidence that mammoths experienced islanders relatives from the mainland. Further findings indicated that a limited population existed 6500 years ago.

To find out exactly when and why extinct “penultimate” mammoths, Graham and his team prodatirovali 14 new animal carcasses, and at the same time took cores from samples of sedimentary rocks from the bottom of a local lake. Each of these capsules kept true chronicle of the times:

sediment samples contain pollen of flowers, remains of plants and microbes that have accumulated on the bottom of the lake the last 10 thousand years..

While some scientists have searched for mammoth DNA samples, others were looking for three types of spores of fungi that live in the dung of herbivorous mammals. As large mammals like mammoths produce large amounts of manure, scientists can track the time of their disappearance to reduce the number of spores in sediments

To the delight of scientists, all five ways -. Remains of mammoths, their DNA, and three types of dispute – given the same result: 5600 years ago. “We were really happy that everything is converged. The beauty of the cores is that they not only told us where the mammoths became extinct, and told all other information about the climate, as well as the – what caused their extinction, “- said Graham.

The cause of their deaths did not man – the first people who find themselves on the island, were Russian whalers who landed here in 1787.

It was not the polar bears that have appeared here much later, and volcanoes, erupted nearby not even once in the last thousand years. Not to say that animals do not have enough space – despite the fact that now it really is a small area of ​​land, the minimum area it has reached at least three thousand years before the extinction of mammoths. Finally, it was not hunger – the analysis of cores showed that pastures on the island was in abundance at the time of death of animals

She killed mammoths banal thirst, which was a result of climate change.. The island has never been streams and rivers. The only source of fresh water for the mammoth remained small lake, at some point began to dry up.

A began to rise due to warming ocean began to fill the coastal lakes, and in the remaining intact sources of fresh water began to penetrate the salt

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There was this is about 7850-5600 years ago, the researchers found by analyzing the remains of microbes, and the isotopic composition of lake cores. This was a disaster for the mammoth, given that modern elephants consume on average 70-200 liters of water per day. But if the elephants are capable of being chilled, sweating, woolly mammoths had this opportunity, and therefore consume more water.

According to the scientists, besides the mammoths themselves accelerated their extinction. Forced to crowd in scarce water sources, they trampled vegetation around, collapsing shore a few puddles and themselves contaminate remnants of clean water. “They seem to themselves hastened his departure” – summed up Graham

According to the scientists, their discovery not only sheds light on the last days of the extinct mammoths, but also shows the importance of the evaluation processes observed in the world today, to. example, on the islands in the Pacific and in Florida.