Michael Crawford is perhaps not strictly considered to be a proponent of what has become known as the "aquatic ape hypothesis" (AAH) but he has long held views about human evolution which are rather closely related to some of its main ideas.
His first major contribution to the debate was the book 'The Driving Force' co-authored with David Marsh which takes the concept of "we are what we eat" and applies it to evolutionary scenarios. Complimenting the Darwinian forces of natural selection which might be thought of as 'negative' (if the individual cannot survive and reproduce, its lineage ceases to exist), the authors promote a more positive driving force for evolution - the never ending search for new food stuffs. It's a strikingly simple point but it is worth remembering that when evolution almost certainly works in this way too. When a population merely, by chance, starts to rely on a different food source, one can think of it as being a kind of positive feedback loop that is food driven, or as a negative feedback loop that is driven be starvation and hence maladaptation. They may be two sides of the same coin but the book does give you a different perspective in which to think of evolution and 'The Driving Force' certainly does that - from The Big Bang, through the origins of biochemical systems in the primordial soup, to life itself and on to human evolution..
In that area, Crawford and Marsh were ahead of their time in proposing that human encephalisation (evolutionary brain growth) could not have happened in environments which were poor in brain specific nutrients, such as on the African savannah. Their thesis was, from the beginning, that this remarkable phenomenon could only have feasible happened on coasts, or at least in waterside habitats rich in essential fatty acids like DHA.
More recently, Crawford been been part of a group of nutritional biochemists, including Stephen Cunnane and Leigh Broadhurst which has published a number of papers promoting a link between human encephalisation (the evolutionary trend to larger brains) and proposed increase in the use of coastal food chain.
Selected Readings
Crawford, Michael A; Marsh, David (1989). The Driving Force. Harper & Row (New York)
Broadhurst, C Leigh; Cunnane, Stephen C; Crawford, Michael A (1998). Rift Valley lake fish and shellfish provided brain-specific nutrition for early Homo. Br J Nutr Vol:79 Pages:3-21
Crawford, Michael A; Bloom, M; Broadhurst, C Leigh; Schmidt, Walter F; Cunnane, Stephen C; Galli, C; Ghebremeskel, K; Linseisen, F; Lloyd-Smith, J; Parkington, John E (2000). Evidence for the unique function of docosahexanoic acid (DHA) during the evolution of the modern hominid brain. Lipids Vol:34 Pages:S39-S47
Broadhurst, C Leigh; Wang, Yiqun; Crawford, Michael A; Cunnane, Stephen C; Parkington, John E; Schmidt, Walter F (2002). Brain-specific lipids from marine, lacustrine, or terrestrial food resources: potential impact on early African Homo sapiens. Comparative Biochemistry and Physiology Vol:131 Pages:653-673
Cunnane, Stephen C; Crawford, Michael A (2003). Survival of the fattest: fat babies were the key to evolution of the large human brain. Comparative Biochemistry and Physiology Vol:136(1) Pages:17-26
Other Links about Crawford
http://www.north.londonmet.ac.uk/ibchn/michael.html
http://www.mcspotlight.org/people/biogs/crawford.html
Algis Kuliukas
March 2006