Neanderthal brain size at birth provides insights into the evolution of human life history

doi:10.1073/pnas.0803917105

Neanderthal brain size at birth provides insights into the evolution of human life history

*Anthropological Institute and Museum, University of Zurich, CH-8057 Zürich, Switzerland;
^‡Laboratory of Prehistory, St. Petersburg 199034, Russia;
^§Kochi University of Technology, Kochi 782-8502, Japan;
^¶Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan; and
^‖Department of Anatomy, Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa 903-0213 Japan

Edited by Erik Trinkaus, Washington University, St. Louis, MO, and approved July 25, 2008 (received for review April 23, 2008)

Abstract

From birth to adulthood, the human brain expands by a factor of 3.3, compared with 2.5 in chimpanzees [DeSilva J and Lesnik J (2006) Chimpanzee neonatal brain size: Implications for brain growth in Homo erectus. J Hum Evol 51: 207–212]. How the required extra amount of human brain growth is achieved and what its implications are for human life history and cognitive development are still a matter of debate. Likewise, because comparative fossil evidence is scarce, when and how the modern human pattern of brain growth arose during evolution is largely unknown. Virtual reconstructions of a Neanderthal neonate from Mezmaiskaya Cave (Russia) and of two Neanderthal infant skeletons from Dederiyeh Cave (Syria) now provide new comparative insights: Neanderthal brain size at birth was similar to that in recent Homo sapiens and most likely subject to similar obstetric constraints. Neanderthal brain growth rates during early infancy were higher, however. This pattern of growth resulted in larger adult brain sizes but not in earlier completion of brain growth. Because large brains growing at high rates require large, late-maturing, mothers [Leigh SR and Blomquist GE (2007) in Campbell CJ et al. Primates in perspective; pp 396–407], it is likely that Neanderthal life history was similarly slow, or even slower-paced, than in recent H. sapiens.

Footnotes

^†To whom correspondence may be addressed. E-mail: marcia{at}aim.uzh.ch or zolli{at}aim.uzh.ch
Author contributions: M.S.P.d.L. and C.P.E.Z. designed research; M.S.P.d.L., L.G., V.D., G.R., T.A., O.K., H.I., and C.P.E.Z. performed research; M.S.P.d.L., L.G., V.D., O.K., H.I., and C.P.E.Z. analyzed data; and M.S.P.d.L., L.G., V.D., and C.P.E.Z. wrote the paper.
The authors declare no conflict of interest.
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