Analysis of fossil teeth from ancient humans and Neanderthals suggests that Neanderthals grew and matured more rapidly than Homo sapiens. This finding helps to pin down an evolutionary origin for humans' prolonged childhood and adolescence, which may have provided an evolutionary advantage.
Tanya Smith at Harvard University in Cambridge, Massachusetts, with Paul Tafforeau at the European Synchrotron Radiation Facility in Grenoble, France, and their colleagues used X-ray imaging to reveal microscopic growth tracks inside fossil teeth from juvenile H. sapiens and Neanderthals (pictured). The tracks indicate developmental features such as daily growth rate.
Dental maturation was faster in the Neanderthals than in both ancient and modern-day humans.