Genetic mutations that made ancient people shorter and more prone to osteoarthritis may have also helped them endure an ice age, the New York Times reports.
"There are many cases like this where evolution is a trade-off," study author and Stanford University researcher David Kingsley tells the Times.
As they report in Nature Genetics, Kingsley and his colleagues focused on a large downstream regulatory region of GDF5 — variants in there have been linked to arthritis and shorter height — that harbors a growth enhancer they dubbed GROW1. They further found a common variant, a G to A conversion, that mapped to within a highly conserved sequence of GROW1.
The G allele, they note, was conserved in placental mammals, but the A allele is present at high frequencies among some human populations, particularly among Europeans and Asians. This derived allele was also found among Neanderthals and Denisovans, the researchers report. This suggested to them that this allele was selected for among northern populations.
Pennsylvania State University's George Perry, who was not a part of the study, tells the Times that though it's possible that a shorter stature could have protected ancient people against a more forbidding climate, that can't be determine with any degree of certainty.