MISSOURI — A new measurement of an early hominid skull suggests that the brain sizes of many human ancestors were overestimated.
Reducing the brain size of many early hominids, experts said, could force serious revision in ideas about the evolution of the human brain.
Dr. Glenn Conroy, an anthropologist at the Washington University School of Medicine in St. Louis, reports in Friday's issue of Science that he has measured the skull capacity of a 2.8 million-year-old hominid with a CAT scanner, a computer-aided medical imaging device.
The hominid's cranial capacity, he found, measured 515 cubic centimeters, considerably less than the 600 cc estimated by another anthropologist.
The findings' implication "is that something is very wrong with the published record of early hominid cranial capacities," Dr. Dean Falk writes in a commentary on the the paper.