Читать книгу Horse Genetics - Ernest Bailey - Страница 21

DNA samples (aDNA) from horse bones at the Botai site in modern Kahzahkstan were tested to determine their relationship to modern horses. The results were surprising. DNA sequences from the Botai bones were not characteristic of modern domestic horses, but rather most similar to the modern Przewalski horses (Gaunitz et al., 2018). The conclusion from this study was that this particular domestication event involved the Przewalski horse species. Furthermore, very little of the DNA from these horses was found among modern domestic horses so this event did not contribute directly to the modern domestic horse. Therefore, although this was the site with the oldest physical evidence of domestication of a horse, it was not the domestication event leading to modern horses. The domestication event leading to the modern horse clearly took place elsewhere. The question remains open. We do not know why this initial domestication event failed. Perhaps cultural or political forces permanently changed the home range or agricultural strategies of the Botai people. It may be that Przewalski horses were ultimately found unsuitable for domestication. When the domestication of another species of horse succeeded, the Przewalski horse may have been abandoned as breeding stock. Indeed, Gaunitz and co-workers (2018) suggested that modern Przewalski horses are actually a group descended from the Botai population. Nevertheless, the DNA evidence shows that people recognized the value of horses and domesticated these animals in Botai about 5500 years ago. However, this event contributed very little to the genomes of modern horses.