Study: Horses, Other Mammals Are Shrinking as Climate Heats Up

It's heating up all over the world and global warming comes with far-reaching consequences on life. One of the effects of rising climate is making certain animals considerably smaller -- and scientists are keeping an eye out for evidence of it happening in the coming future.

According to a report from Phys Org, the study noted two other times in the Earth's history when a naturally occurring temperature spike led to warm-blooded creatures shrinking in size.

In the wake of today's well-documented global warming, lead author and University of New Hampshire researcher Abigail D'Ambrosia cautioned that animals could be facing the same fate now. In fact, the man-induced warming could cause the animals to change size even faster than natural environmental changes did.

It was 54 million years ago when the temperature dramatically rose and shrunk three known species including an early horse and a lemur-like animal that's the earliest known primate.

An analysis of fossil teeth from the Bighorn Basin of Wyoming estimated that horse became 14 percent smaller, going from 7.7 kilograms to 6.6 kilograms. D'Ambrosia described it from being the size of a dog to the size of a cat. Meanwhile, the primate shrunk by about 4 percent, a significant decrease in size considering the animal was usually recorded to be getting bigger over millions of years.

An earlier warming 56 million years ago also recorded a similar shrinking of animals including a different early horse ancestor.

"Dwarfing appears to be a common evolutionary response of some mammals during past global warming events, and the extent of dwarfing seems related to the magnitude of the event," D'Ambrosia explained in a report from Telegraph.

Some of the factors that led to the shrinking of the animals may have been nutrient availability, which may have been caused by rising temperatures and drought.

She added, "Drought conditions have been known to lead to smaller offspring."

The researchers published their findings in the journal Science Advances.