Researchers have discovered how the ancestors of modern horses migrated
An international research team has determined that the ancestors of modern domestic horses and Przewalski’s horse moved from the territory of Eurasia (Russian Urals, Siberia, Chukotka and eastern China) to North America (Yukon, Alaska, continental United States) from one continent to another at least twice. This happened during the Upper Pleistocene (2.5 million years ago – 11.7 thousand years ago). The results of the analysis are published in the journal. The results and description of horse genomes are published in the journal Molecular ecology.
“We discovered that the Beringia land bridge, or the area known as Beringia, influenced genetic diversity in horses and beyond,” said Dmitry Gimranov, senior researcher at the Urals branch. from the Russian Academy of Sciences and the Federal University of the Urals (Russia). “Due to the appearance of this part of the earth, gene flow among mammoths, bison and wolves could occur regularly. And if 1 to 0.8 million years ago, American horses from the North were not yet widespread in Eurasia, so in the periods of 950 -450 and 200-50,000 years ago, there was a two-way spread of genes over long distances. ”
In other words, horses migrated between continents not only in one direction but also vice versa. The first wave of migration was mainly from North America to Eurasia. The second migration was dominated by the movement from Eurasia to North America.
Leading researchers conclude that most animals only used the Beringian land bridge once, and horses several times. This fact could significantly affect the genetic structure of horse populations and has made them very interesting research subjects for paleogeneticists.
To determine the area of installation of the horses, molecular biologists studied the DNA of horses from both continents. Out of 262 bone and tooth samples, they selected 78 with enough DNA. Researchers performed radiocarbon dating and genetic analyzes in laboratories in Denmark and the United States. In addition, they examined research data from 112 samples.
“The data shows that horses returned to North America from Eurasia through Beringia at about the same time as bison, brown bears and lions,” says Dmitry Gimranov. “That is, in the last ‘days’ of the late Pleistocene, when the land was not covered with water and it was like a bridge for the movement of many groups of animals. With the beginning of global warming (the beginning of the Holocene or 11.7 thousand years) and the last disappearance of Beringia at the end of the Pleistocene, the biogeographical importance of this ecological corridor has radically changed the history of terrestrial animal species on the two continents.
Although the North American horse population eventually became extinct during the early Holocene, horses spread across both continents due to domestication and are now found far beyond their historical range.
The Bering Land Bridge was located at the site of the modern Bering Strait, separating the far northwest of America and the far northeast of Asia. The physical and geographic region of Beringia stretched from the Lena River in Russia to the Mackenzie River in Canada. It included both land and sea elements. The area of Beringia changed during the Pleistocene (from 2.6 million years to 11.7 thousand years) as did the size of continental ice and its effect on sea level.
Warning: AAAS and EurekAlert! are not responsible for the accuracy of any press releases posted on EurekAlert! by contributing institutions or for the use of any information via the EurekAlert system.