Madrid, May 7 (EFE).- Eleven of the 13 Neanderthals who lived in northern Spain's El Sidron cave were right-handed, indicating that these cousins of modern humans had a brain structure similar to that of Homo sapiens, a study published in Plos One magazine said.
Researchers, among them members of Spain's CSIC research council, analyzed grooves in more than 60 Neanderthal dental pieces.
Manual laterality "reflects specialized organization of the brain, so its evolutionary origin has been the subject of research for decades," project director Antonio Rosas said.
Although some primates can have a certain degree of preference for the use of one of their hands, strict laterality - a spontaneous preference for the use of limbs located on the right or left side - has only been observed in human species, Rosas, who is with the National Museum of Natural Sciences, said.
The ability to study 11 Neanderthals (Homo neanderthalensis) from the same group together was a unique opportunity, but researchers must still determine whether the other two individuals in the group were right-handed or left-handed since their dental pieces did not survive, Rosas said.
Of the 27 Neanderthals studied around the world so far, just two appeared to show a preference for using their left hands, a percentage comparable to that in modern humans, researchers said.
Human beings evolved about 100,000 years ago in Africa and modern humans spread into the Middle East, Asia and Europe some 50,000 years ago, while Neanderthals eventually became extinct.