The Foundation is proud to announce that Dr. Leslie Aiello, president of the Wenner-Gren Foundation, was awarded the 2006 Huxley Memorial Medal. This award is the highest honor at the disposal of the Royal Anthropological Institute, in the United Kingdom and was instituted in 1900 in memory of Thomas Henry Huxley. The medal is awarded annually, by ballot of the Council, to a scientist, British or foreign, distinguished in any field of anthropological research in the widest sense. Recent recipients of the award include Marilyn Strathern (2004), Gannanath Obeyesekere (2003) and Jane Goodall (2002) among others.
Dr. Aiello gave the Huxley Memorial Lecture: "Diet, Energy and Human Evolution" on Thursday the 7th December 2006, 6.15 p.m. in the Stevenson Lecture Theatre, British Museum, Great Russell Street, London WC1.
The lecture expands on the work taken place over the 10 years since the publication of the Expensive Tissue Hypothesis (ETH) (Aiello & Wheeler, 1995, Current Anthropology 36:199-221), which suggested that there was an inverse relationship between the sizes and energetic costs of the brain and the digestive system. A larger brain would require a correspondingly smaller digestive system in order to maintain a BMR (basal metabolic rate) that was not excessively elevated over Kleiber expectations and a smaller digestive system would only be possible with the adoption of a higher quality diet. The original ETH posited that a relatively small gut and implied dietary change were already features of Homo ergaster (c.a. 1.6 mya). It also suggested that the inverse relationship between brain size and gut size was a feature not only of humans but also of the other primates.
The past decade has seen considerable research into both hominin diet and energetics. Evidence from the archaeological context, dentition, postcranial proportions and morphology, carnivore guild turnover and hominin tapeworm genetics are consistent with the incorporation of increased amounts of animal-derived food in the diet of early members of the genus Homo. Research testing the broader implications of the ETH has demonstrated a robust positive correlation between dietary quality and brain size in primates but has also suggested that dietary change may not have been the sole factor that balances the energetic expense of the hominin large brain. How valid is the ETH today? In the context of this new research, the applicability of the ETH to hominin evolution is reassessed.