Some early humans living 100,000 years ago in northern China had a rare birth defect that prevents the holes in the skull present at birth from ever growing completely closed. That’s what scientists from the Chinese Academy of Sciences and Washington University in St. Louis have concluded after examining the skull of adult with “an enlarged parietal foramen (EPF).” Yes, EPF is a fancy way of saying that the skull had a natural hole in the top of it.
A detailed study of the skull, complete with photographs, has been published in open access journal PLOS One.
EPF still occurs in modern humans as the result of a very rare genetic defect found in one in 15,000 to 25,000 people. In a normal baby, the soft gaps in the skull have grown closed after five months, but in someone with EPF, the soft spots in the skull will always remain. Pressing on those holes in the head can cause extreme pain, and a few people with EPF may experience seizures or other medical problems.
The ancient Chinese skull belonged to someone who lived into middle age, so the condition presumably didn’t prove to be a handicap, even in a relatively harsh Pleistocene environment. It’s hard to tell if the person had any other deformities, since the team didn’t locate the complete specimen.
Although it’s only one skull, Erik Trinkhaus, the lead author, told Live Science that there are a number of other early human skulls from the Pleistocene era that bear evidence of rare genetic deformities. “These populations were probably relatively isolated, very small and, as a consequence, fairly inbred,” he said.
Inbreeding happens when closely related people mate, greatly increasing the chance that a child will inherit the genes from both parents needed to express a rare recessive trait.
Deformed early humans with holes in the head? Sounds like somebody we’ve seen on daytime TV.
[skull photos courtesy Xiu-Jie Wu, Song Xing, and Erik Trinkaus]