The international group of scientists for the first time received DNA of the ancient bears, highlighting it from cave dirt. Researchers call it a revolutionary achievement in the field of environmental genomics, which is comparable to a man falling on the moon. This is reported in the article published in the journal Current Biology.
Samples of biological material (excrement and remnants of wool) were obtained in the Chikiuita cave, where the archaeologists were previously found stone tools and traces of human activity of 25-30 thousand years. In sediments, bones and DNA of ancient animals are also preserved, including bears, bats, voles and kangarov jumpers. The researchers sequenced DNA using the most powerful methods for deciphering the nucleotide sequence, and completely recreated the genomes of two bears who lived during the upper paleolithic times.
One part was the ancestor of the modern American Black Bear (Ursus Americanus), and the other – extinct 11 thousand years ago by the Giant Short-forming Bear (Arctodus Simus), which is one of the largest ever bears. The researchers compared their genomes with genomes of other bears, including DNA of 83 modern black bears from the USA and Canada and three giant short bears, who lived on the Yukon in Canada about 22 thousand years ago.
Black bears from Chikiuita are closely related to modern bears in North America, but also have a general origin with black bears in Alaska. Shortwordy bears, inhabited in Northern Mexico, was very different from the population of short-cast bears who lived in the North-West Canada.
Until now, the studies of ancient DNA extracted from the environment (or environmental DNA) were limited to the DNA of mitochondria and chloroplasts or short and varied fragments of genomes, according to which one can judge the taxonomy of biological communities. New work expands this area to studies of genetics of populations and phylogenetics.