Researchers at the Universities of Manchester (UK) and Barcelona (Spain) studying 390 human skulls from Hallstatt, Austria, have shown that changes to skull shape long thought to have been separate events may actually be connected.
     The skulls are part of a famous collection; local tradition dictates that the remains of the town's dead are buried but later exhumed to make space for future burials. The skulls are decorated with paintings and, crucially, bear the name of the deceased. The Barcelona team made measurements of the skulls and collected genealogical data from records of births, marriages and deaths, allowing them to investigate the inheritance of skull shape.
     The team tested whether certain parts of the skull changed independently, as anthropologists have always believed, or were in some way linked. They found that, rather than being separate evolutionary events, changes in one part of the brain would facilitate and even drive changes in the other parts.
     According to Dr Chris Klingenberg, of Manchester University's Faculty of Life Sciences, "We were able to use the genetic information to simulate what would happen if selection were to favour particular shape changes in the skull. For each of the simulations, we obtained a predicted response that included not only the change we selected for, but also all the others. All those features of the skull tended to change as a whole package. This means that, in evolutionary history, any of the changes may have facilitated the evolution of the others."
     Lead author Dr Neus Martínez-Abadías, from the University of Barcelona, added: "This study has important implications for inferences on human evolution and suggests the need for a reinterpretation of the evolutionary scenarios of the skull in modern humans."

Edited from ScienceDaily (20 December 2011)