2), were viewed as emblematic indicators of postglacial times and human economies (Bailey, 1978, Binford, 1968 and Waselkov, 1987). Regardless of the accuracy of such assessments, it is true that the late Pleistocene and Holocene are marked by a global explosion of anthropogenic shell midden soils that are highly visible stratigraphic markers in coastal, riverine, and lacustrine settings around the world. In some areas, this terrestrial signature is accompanied by submerged records associated with ancient shorelines. The most dramatic and best documented

of these submerged landscapes is the Mesolithic shell middens of Denmark, where nearly 2000 ‘drowned’ terrestrial sites have been recorded (Fischer, 1995). Such submerged archeological sites, along 5-Fluoracil nmr with sub-aerial sites found around Pleistocene freshwater lakes, marshes, and rivers, suggest that the global post-glacial proliferation of coastal shell middens has been exaggerated by the complex history of sea level fluctuations during the Pleistocene. How long have hominins foraged in aquatic ecosystems and how have such activities changed through time? Our ancestors evolved a biological cooling system heavily reliant on sweating, which puts a premium on proximity to fresh water sources and a need for regular replenishment of sodium (Kempf,

2009). The need for freshwater has required hominins ABT-888 mw to remain closely tethered to aquatic habitats (lakes, rivers, streams, springs, etc.) or to develop storage systems that allowed them to venture further from such water sources Orotic acid temporarily (Erlandson, 2001). Recently, some

human physiologists and nutritionists have also argued that the expansion of the hominin brain was not possible without regular access to brain-specific nutrients such as iodine, selenium, and docosahexanoic acid (DHA) required for the effective function of large-brained organisms—nutrients most readily found in aquatic plant and animal foods (e.g., Broadhurst et al., 1998, Broadhurst et al., 2002, Crawford et al., 1999 and Cunnane, 2005). These observations have led to a recent theory that aquatic habitats and foraging were critical to the evolution of large-brained hominins (Cunnane and Stewart, 2010). If this theory is wholly or partially correct, there should be archeological evidence for early use of aquatic habitats and resources associated with sites occupied by Homo habilis, H. ergaster/erectus, and more recent hominins beginning about 2.5 million years ago. There is evidence for aquatic foraging by hominins, but it has been underemphasized in the anthropological literature (Erlandson, 2001 and Erlandson and Fitzpatrick, 2006). At Olduvai Gorge, for instance, H. habilis and H. ergaster appear to have fed on fish and other freshwater foods from East African lakes between two and one million years ago ( Braun et al.