Evolution is usually considered a slow process taking hundreds if not thousands of years. But Siberian horse evolution may be on a fast track due to the extreme conditions of the frigid region.
According to research discussed in Popular Mechanics small and hardy Yakut horses may have evolved quite quickly because of the region and its climate. Researchers say the horses may have developed a form of “standing hibernation.” In that sense they may have taken a leaf from squirrels. Arctic ground squirrels cycle in and out of torpor. Their bodies can reach a low of 32F and then move back to normal temps to perform critical functions. They awaken at the end of winter in good health.
The Yakut horse or Siberian horse (Equus ferus caballus) is the first horse that has been shown to practice this unusual hibernation form.
The magazine said:
“One of the key traits of these horses is their ability to lower their metabolic rate, heart rate, and body temperature in the extreme cold—much like ground squirrels, and roughly a dozen other animals—to mimic hibernation states for hours on any given day. Because the horses remain active during their extended periods of torpor, scientist have dubbed the situation “standing hibernation.” This is the only known example of this ability in horses.”
Moreover, the adaptation appears to have happened extremely quickly in evolutionary terms.
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In the Arctic climate of Northern Siberia, temperatures can drop to -90 degrees Fahrenheit in the winter and stretch to a reasonably balmy average of 70 degrees Fahrenheit in the summer. But, perhaps unsurprisingly, it’s those extreme winters that have scientists fascinated with the Yakut breed.
A study published in Genes shows the Yakut horse is one of the oldest local breeds, formed in the far north of Yakutia several thousand years ago and traditionally used for meat, milk production, and riding. The “most cold-resistant indigenous breed,” it was developed under a “strong influence of natural selection,” the authors wrote in the Genes study.”
“… the genes involved in hair development, body size, and metabolic and hormone signaling pathways that serve a key resource for Yakut horse adaptability all had to develop much more quickly than previously understood. The authors added that the ability of the Yakut horses to adapt to the extreme environments isn’t that unlike what they’ve found in native human populations and woolly mammoths, “suggesting that only a few evolutionary strategies are compatible with survival in extremely cold environments.” ” (link in original)
