Tuesday, May 17, 2011

More than 500,000 years of right-handedness in Europe

Considerable research supports the high frequency of right-handedness in living Homo sapiens, with worldwide rates of approximately nine rights-for every one left- hander. Right-handedness appears to be a uniquely human trait, as no other primate species, no matter how proficient in tool use, shows frequencies even close to the strong right bias typical of humans.

Here we review our research on human fossils from Sima de los Huesos (Atapuerca, Spain) and their likely descendants, the European Neandertals. We document hand preference in fossils by scratch patterns that occur on the labial (lip) face of incisors and canines, and contend that these patterns provide a reliable means for identifying predominant hand use in these samples. Manipulatory marks on the anterior teeth show a persistent pattern of right-handedness actions, implying that the modern human pattern of dominant right-handedness extends deep into the European past.

Right-handedness has long thought to be associated with left cerebral dominance and language. Usually, language is left lateralized in brains of right-and left-handers and in both sexes. Many neurologist and palaeoneurologists accept the relationship between language, lateralization, and handedness (Falk, 1987; Holloway, 1976; Knecht et al., 2000). Discovery of the FOXP2 gene sequence in two male El Sidron Neandertals dated before 50,000 years ago (Krause et al., 2007) is consistent with the existence of language between neandertals. And the most likely evolutionary scenario is that the common ancestor of living humans and neandertals hared the modern sequence and had the elemental protein associated with language production. If correlations between handedness and laterality hold, evidence from Sima de los Huesos now pushes modern language capacity to greater than 500,000 years ago.


Frayer, D. W.; Lozano, M.; Bermúdez de Castro, J.M.; Carbonell, E.; Arsuaga, J.L.: Radovcic, J.; Fiore, I.; Bondioli, L. (2011) “More than 500,000 years of right-handedness in Europe. Laterality: Asymmetries of Body, Brain and Cognition”. Laterality, First published on: 14 April 2011 (iFirst)


Marina Lozano