Monday, December 16, 2013

And the rains washed away the deer trail - Mail.Ru

The scientific community is now increasingly wonders animal adaptation to global climate change. Scientists believe to adapt to such changes often helps mammals intraspecific genetic diversity. Under adverse weather conditions allowed for several generations can significantly increase or decrease the contrary genetic diversity in a given population, if it is necessary for the survival of the species.

In light of current climate change, many researchers consider it crucial to examine the impact of severe natural disasters since the late Pleistocene on the survival of many species of mammals

One example of such an interdisciplinary scientific research was a study undertaken by an international team of scientists, which included representatives of the Russian Institute of Ecology and Evolution. AN Severtsova RAS and the Research Institute of Agriculture of the Far North of the RAAS. The aim of the study was an attempt to show the effect of climate change on the last dwelling in the vast territory of view Rangifer tarandus, known to all as reindeer, and simulate how animals can act climate change in the future. Choice scholars fell on deer, because they live in northern latitudes, where seriously felt the impact of global climate change, including rising temperatures.

This means that soon this species will inevitably face direct and indirect influence new to him, weather conditions, according to the scientists published an article in the scientific journal Nature Climate Change.

To start the scientists decided to make a picture of the historical movements of populations of deer during the Late Pleistocene.

this purpose used a special computer model to calculate the migration routes of ancient animals on the North American Holarctic and Eurasian routes up to their present settlement. The simulation results were compared with the map of genetic diversity, compiled on the basis of 1297 samples of mitochondrial DNA from different populations of animals that had to show the level of genetic diversity in the resettlement. After receiving the data, the researchers examined the main climate change on reindeer migration route over the past 21,000 years, as well as by computer reconstruction of natural changes calculated the effect of global warming on animals up to 2080 inclusive.

As it turned out, that climate changes over the past two decades thousands of years were the main reason for the formation of two major pathways phylogeographic reindeer whose representatives often have different levels of genetic diversity.

In today inhabit the territory of Canada from Newfoundland to animals (phylogeographic way which scientists dubbed “North American”), the largest variety of genes was observed about 10 thousand years ago, when coldwater deer enjoyed a sharp drop in temperature in the Americas. Taken a liking to a vast territory in Eurasia deer so-called “Eurasian-Pelagic” different ways greatest genetic diversity about 2 thousand years ago, again due to steady while in Eurasia most suitable climate for animals.

This observation allowed scientists to concluded that the formation of stable most comfortable climatic conditions for deer leads to a sharp increase in population, which undoubtedly leads to a higher level of genetic diversity. The researchers also believe that an important role was played by the terrain, since, given the ability to make long deer crossings, only natural barriers could become a barrier for contacts between populations and, consequently, increase the diversity of genes.

If you talk about projections to 2080, the global warming will have a significant impact on both the populations and their genetic diversity. With the greatest difficulty faced deer “North American” phylogeographic way.

Over the next 60 years, about 89% of the territory where today live animals would be unsuitable for them.

This will cause a sharp decline in populations and lead to a drop in the level of their genetic diversity. This trend is reflected today, as many deer subspecies in North America and Canada are threatened with extinction. The fate of the deer “Eurasian-Pelagic” way more optimistic. Due to global warming by 2080, they will lose about 60% of its current territory habitat. According to scientists, this ensures not only greater, compared with North American relatives, populations and a better variety of genes, but also contains a great potential for evolutionary change, aimed at adapting to new climatic conditions.

Author: Vladimir Todorov

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