Proof that laziness can be an evolutionary gain

By Kelli Bender
Updated October 21, 2016 05:52 PM
Credit: Hoberman Collection/UIG/Getty

With sloths’ relaxed and tardy nature, it seems fitting that news of the mammal’s recent achievement is spreading a day after International Sloth Day.

According to the Scientific American, research has proved that sloths officially have the slowest metabolism of any animal on Earth.

This impressive title was bestowed upon the animal after a seven-year study of three-toed sloths by scientists from the University of Wisconsin-Madison.

“We expected them to have low metabolic rates, but we found them to have tremendously low energy needs,” ecologist Jonathan Pauli told Scientific American, with a description that can also be used to describe many of us on a Sunday morning.

Pauli and his colleague M. Zachariah Peery measured the metabolic rates of numerous three-toed and two-toed sloth varieties and compared them to other leaf-eating mammals.

The three-toed sloth, a creature famous for having a life so leisurely that moss is able to grow on its back, won the slow metabolism contest, only expending 162 kilojoules per day per kilogram of energy to get by. The two-toed sloth had a little more hustle with 234 kilojoules. The only close competition for the three-toed sloth was the panda, with an average daily energy expenditure of 185 kilojoules per day per kilogram.

Sloth can survive being this lazy thanks to a series of adaptations like a small home range and long nap breaks. The mammals can also regulate their body temperatures, which helps them from burning extra energy in their many dormant moments.

See, Mom! Laziness can lead to success!