Shortness, reduced mobility and sore joints may not come to mind when you think of survival of the fittest. But human evolution could suggest otherwise.

In a new study, researchers found that as early humans migrated into colder northern climates, a genetic mutation that knocks about a centimeter off height and increases the risk of osteoarthritis by up to 80 percent may have helped some of them survive the most recent ice age.

While some traits resulting from this mutation may seem unfavorable today, they were advantageous to early humans venturing out of Africa about 60,000 years ago.

“There are many cases like this where evolution is a trade-off,” said David Kingsley, an author of the study, which appeared in Nature Genetics on Monday, and a professor of developmental biology at Stanford University.