A new study has revealed that more than 50 million years ago, some animals shrank in size in response to a series of extreme global warming events.

Effect Of Climate Change On The Early Horse Species Arenahippus

Researchers of the study, which was published in Science Advances, found that some ancient animals which include the dog-sized Arenahippus, an early horse, became smaller as levels of carbon dioxide and temperatures rose as part of natural global warming.

By analyzing fossil teeth, researchers found that the ancient compact horse became 14 percent smaller going from 17 pounds to 14. 6 pounds.

"These guys were probably about the size of maybe a dog, then they dwarfed," said study researcher Abigail D'Ambrosia, from University of New Hampshire. "They may have gone down to the size of a cat."

An Evolutionary Response

Researchers said that changes in the body could be an evolutionary response that can help animals to efficiently reduce body heat as a smaller body size would allow them to cool down faster. The availability of nutrients and quality of food may also have a role.

The impact of climate change on animals, and even plants today, has also been documented by several studies. Researchers were able to conduct observations that suggest modern-day creatures also go through evolutionary processes to adapt to a warming world popularly blamed on carbon emissions.

Effects On Animals

Just like the Arenahippus that evolved to adapt to a warmer planet, many animals that exist today became smaller in response to climate change. A 2014 study found that wild salamanders have been shrinking since 1957. Researchers think that the Appalachian salamanders get smaller in size due to drier and warmer conditions created by global warming.

The migratory bird red knot has also experienced dramatic shrinking since 1985. Since the Arctic has been warming up earlier as a result of climate change, the snow melts two weeks earlier than decades ago. The insects in the Arctic respond to this shift by hatching earlier.

When red knot chicks hatch though, the insects are already past their peak so food source becomes scarcer. As a result, the shorebirds develop smaller bodies and shorter bills. Being smaller, however, threatens the population of the birds, which could even possibly lead to their extinction.

"Shorter-billed birds were forced to live on seagrass, which is a poor food source for these birds. The poor survival of shrunken first-year birds clearly contributes to the current population decline seen in red knots nowadays," explained Jan van Gils, from the Royal Netherlands Institute for Sea Research.

Effects On Agricultural And Wild Plants

Plants are affected as well. In a 2016 study, researchers found that extreme heat waves and droughts have led to a reduction in global cereal harvests such as wheat, rice and maize within a period of 50 years, essentially affecting agriculture and food production.

In another study, researchers who looked at the DNA markers in plants found that exposure to climate change conditions led to altered genetic composition of wild plants.