Neanderthals living 49,000 years ago may have abided in small clans banded together by their male kin.

Carles Lalueza-Fox at Pompeu Fabra University in Barcelona, Spain, Antonio Rosas at the National Museum of Natural Sciences in Madrid and their colleagues analysed the remains of 12 Neanderthals. They sequenced certain regions of the mitochondrial DNA extracted from fragments of bones and teeth.

The results showed that the group's three adult males were close relatives, but the three adult females were not. The authors further inferred that an infant and two juveniles were offspring of two of the adult females. The team suggests that the individuals represent a social unit based on patrilocality, in which individuals live with the adult male's family.

Proc. Natl Acad. Sci. USA doi:10.1073/pnas.1011553108 (2010)