The Przewalski Horses
Przewalski horses are ancestral, and wild relatives of domesticated horses. However, the connection between the two is much older than previously thought. The two subspecies began in different evolutionary paths 45,000 years ago, according to a study published in Current Biology.
Przewalski horses differ from domesticated horses in many biological aspects, including the fact that they have a different number of chromosomes. Still, they are considered of the same species, since they can be successfully reproduced with domesticated equines – something that several experts disagree for several decades.
In this study, researchers examined the genomes of 11 wild horses – living individuals and specimens that have been found in the museum for more than 100 years. Then they compared their DNA to that of 28 domesticated horses: the former were domesticated 5,000 years ago, according to fossil discoveries. So the scientists found genetic differences in metabolism, heart disorders, muscle contractions, reproduction and neurological pathways.
Prezewalski’s live observation also demonstrates the great differences in appearance and behavior, since wild horses are quite aggressive and never managed to domesticate them.
On the other hand, there are today only 2,000 Przewalski horses on Earth. They were initially in the late nineteenth century in Mongolia by the Russian explorer Przhevalsky. In the following years, several wild horses were taken to captivity, where they did not get along: many did not survive the trip to civilization, others died in zoos or war. Those who stayed were eventually extinguished due to the degradation of habitat and hunting.
The last sighting of a przewalski horse in the wild occurred in 1969 in the Gobi Desert in Mongolia. This wild horse species has suffered to regain, but the effort has paid off. Currently, there are more than 400 specimens in the wild and more than 1,500 in captivity. The reintroduction programs carried out by China, Mongolia and Kazakhstan have been fruitful, but genetic diversity and inbreeding remain a serious problem.