Makova added that, although the two species diverged well over 100,000 years ago, they have interbred periodically since then. "Also fortunate is the fact that conservationists in the second half of the 20th century realized how grave the situation was for the Przewalski's horse. They not only began new breeding efforts and built wildlife reserves in California and the Ukraine, but they also made sure to avoid inbreeding among close relatives," Makova said. "For this reason, the present-day population has managed to remain healthy by retaining substantial genetic diversity."
Makova and her team hope that their findings will help guide future conservation efforts for the endangered horse species. "The idea is to gradually reintroduce Przewalski's horse into the wild," Makova said. "For example, now that we have a more thorough understanding of the different maternal lineages, we can diversify the animal's gene pool even more. This will be a way to ensure that members of wild species suffer as few recessive diseases as possible and have the best opportunity to flourish once they are introduced into the appropriate habitat."
In addition, the researchers hope to further horse-evolution studies by sequencing the genomes of additional breeds of domestic horses, and, eventually, by sequencing the complete genome of Przewalski's horse. "More genetic data means a more precise evolutionary clock," Makova explained. "The more we know, the more we can adjust the time frame for when Przewalski's horse and other horses diverged from their common ancestor." Makova added that she and her team also would like to identify the genes that code for the physical differences between Przewalski's horse and the domestic horse. "It's always been a curious question why Przewalski's horse is so much shorter and stockier in stature than the domestic horse, and also why Przewals
|Contact: Barbara Kennedy|