| Abstract: |
Disagrees with Reaven's (1998) hypothesis that the thrifty genotype gene was not one which conferred exceptionally storage of food energy but instead conserved muscle protein during periods of starvation by reducing gluconeogenesis from amino acids. Hypothesis assumes that pre-agricultural people must have gone through regular periodic episodes of starvation that had a negative impact on reproductive success. They note that pre-agricultural episodes of periodic starvation is infrequent and is not truly represented in the ethnographic literature. It was not not until agriculture that we find evidence for periodic starvation. They feel that if Reaven's and Neel's hypothesis is correct then the advent of agriculture would not have reduced the selection for a thrifty genotype, but would have actually increased it. Cordain et al use Europe as their example when they should have been using the Pacific as well. They due make the good point in that starvation probably is not the sole factor in selecting for a putative "thrifty" or "not-so thrifty" genotype. They like the idea proposed by Brand and Colagiuri (1994) that insulin resistence would have conveyed a selective advantage for populations consuming high protein and low carbohydrate diets long-term because it would have maximized gluconeogenesis and thereby reduced glucose away from muscles, facilitating the preferential use of glucose by the brain, fetus, and mammary gland.
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