The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)


Brain growth, energetics, and the slow life history of Neanderthals

CHRISTOPH P. E. ZOLLIKOFER and MARCIA S. PONCE DE LEÓN.

Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland

March 26, 2015 8:30, Grand Ballroom D Add to calendar

Compared to present-day humans, Neanderthals are typically characterized as having followed a fast-track life history. Most data supporting this view come from comparative studies on dental maturation. The reconstruction of Neanderthal brain growth trajectories, however, yields opposing evidence. Growing larger-than-modern brains incurs higher metabolic costs, a substantial proportion of which has to be covered by larger, slower-maturing mothers. Here we investigate how the contradicting life-history implications from Neanderthal teeth and brains can be reconciled in the light of new empirical evidence on metabolic costs of brain growth and an infant's daily energy expenditure. Data on fossil endocranial volume increase can now be converted with fair reliability into rates of metabolic energy throughput. Also, data on dental maturation can tentatively be expressed in terms of changing energy source allocation. This metabolic approach permits to explore how evolutionary shifts in brain and dentognathic development influence infant, maternal and allomaternal energy flows, and life history parameters of Neanderthals and present-day humans. Our analyses suggest that hominin life history evolution has more degrees of freedom than suggested by the slow-fast paradigm. Accordingly, the conflicting dental and neurocranial evidence regarding the pace of Neanderthal life history can be resolved by a revision of hominin life history theory.

Funded by the Swiss National Science Foundation (grant #31003A_135470).