Inner Ear Provides Clues to Human Dispersal

The early migration of humans out of Africa and across the world can be proven using genetic and morphological analyses. However, morphological data from the skull and skeleton often only allow limited conclusions to be drawn about the geographical dispersal pattern, especially because of the many ways in which the human skeleton adapts to local environmental conditions. Now, an international team of researchers led by paleoanthropologists from the University of Zurich has shown that the morphology of the inner ear is a good indicator for population history and human dispersal. Differences within a population greater than between populations. The hearing and balance system in humans, as in all vertebrates, is housed in a cavity system in the base of the skull - the bony labyrinth of the inner ear. The researchers analyzed the labyrinth structures in human populations from southern and northern Africa, Europe, Asia, Australia, and America, including as far south as Patagonia, using computed tomography to obtain high-resolution 3-D data of the bony labyrinth. The data showed that the shape of the labyrinth varied greatly, with the variation within a population being considerably greater that the variation between populations.