on evolution, genetics, human diversity, evolutionary ecology, physiology and more...
Saturday, June 02, 2007
Aquatic ape, continued
back and forth, we go. I don't have time to read the argument here, but this new issue of AJHB has two other (here, here) papers that discuss the issue, the second look like a rebuttal to this rebuttal.
Stephen C. Cunnane, Mélanie Plourde, Kathy Stewart, Michael A. Crawford
American Journal of Human Biology, Volume 19, Issue 4 , Pages 578 - 581
Abstract: Carlson and Kingston (: Am J Hum Biol 19:132-141) propose that preformed dietary docosahexaenoic acid (an omega-3 fatty acid in fish) did not have a significant role in hominin encephalization. Their position hinges on claiming that humans are able to make sufficient docosahexaenoic acid from the plant-based parent omega-3 fatty acid - -linolenic acid. They also suggest that hominin fish consumption occurred too late to have materially influenced encephalization. The authors quantify here a summary of the published data showing that humans cannot make sufficient docosahexaenoic acid to maintain normal infant brain development. The authors also provide evidence that the fossil record shows that some of the earliest hominins were regularly consuming fish. Hence, we reject Carlson and Kingston's position and reiterate support for the concept that access to shore-based diets containing docosahexaenoic acid was necessary for hominin encephalization beyond the level seen in the great apes.