Dr. Noah Brosh, Ma'ariv
In one nature reserve in Mongolia live several dozen unique wild horses. These horses, which are almost completely extinct, are the only horses that exist today that are not descendants of the domesticated horses we know. A new genetic study focused on them to find out exactly when the modern horse "separated" from its ancient ancestors.
The Mongolian wild horses were discovered to the world at the end of the 19th century by the Polish colonel Nicolai Przewalski, who went on a journey in the region. Since then, they have been known as "Pazhwalski horses". The population of these horses has plummeted since then, and few of them have survived in zoos and private estates.
The new study, by Swedish and American scientists, focused on the Y chromosome of horses, which appears only in males. This, after they found a great difference in mitochondrial DNA (which originates from mothers only) between different races. Compared to the great variation in DNA from the maternal source, it turned out that the genetic load in the Y chromosome of 52 horses from Europe and Asia is not different at all. The explanation for this is that the current horse population has many different mothers, but probably a smaller number of different fathers. The scientists' conclusion was that even in herds of wild horses there is a male leader who fertilizes many females. In the Mongolian horses, the scientists also found a great difference in the Y chromosome, due to mutations that passed through many ages, since the ancient horses separated from their modern brothers.
The genetic research showed that the "distance" between them and modern horses is at least 120 thousand years - much longer than the earliest possible domestication date for horses, which began about 10,000 years ago.
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