| Abstract: |
Adaptation is the theme with which Haas and Harrison (1977) intertwine their review of nutritional adaptation, a kind of adaptation, which is probably neither solely biological nor social in character. They choose to review only the biological aspects of nutrition and adaptation, but provide reader with citations dealing with the sociocultural aspects of food and nutrition. Their review leads progressively from a brief description of the concept of multiple stress environments, where nutrition (or lack of it) is a contributive stress, to Mazess (1975a, 1975b) notion of "adaptive domains", mirroring much of last week's discussion about levels of analysis from the biochemical up to the individual and population level. These adaptive domains are the functional variants at each level of organization, but can occupy places up or down this hierarchy as well. This concept of adaptation at many levels makes more sense and is better conceptualized than Thomas' (1975) 'stressor-buffer' feedback system that seeks to avoid the costly genetic response by behavioral and biological adaptations, especially for building more complex but more empirically sufficient mutlistress models. <P> Haas and Harrison discuss several previously assumed single stress models in an attempt to include nutritive models into the single stress explanations. Cold stress relates to nutrition in three main ways: maintenance of adipose layer
efficient metabolic response to hypothermia
and growth and development to reduce heat loss in adults. Nutrition and heat stress has been less well studied, but productive areas include protein stress in tropical climates and vitamin and mineral maintenance in very hot climates where sweating and dehydration are common. UV radiation and hypoxia are also reviewed. <p> Under the subject heading Behavioral Responses and Nutritional Variation, the authors cover some interesting topics such as behavioral responses to nutritional limitations of staple crops, such as mixing protein rich foods into the rice-based diet, and amino acid complimentarily of binary or ternary cropping systems, and foods with pharmacologic effects such as manioc for sickle cell and coca for its effects at elevating blood glucose. The behavioral study of such processes is the only way to get at these features of nutrient adaptation, because each region has derived its own solution to the nutrient stress. Biologically we can understand the specific nutritional pathways that these adaptations take, but the behavioral component helps explain the variety of responses. <p> The last main section deals with Biological Variability and the Environment, and examines the adaptive domains of nutritional use by different populations by body form, hyperefficiency diseases such as obesity and diabetes, and glucogenesis, or sugar processing. Evidence in this form is more compelling for the study of adaptation than the rest of the chapters' topics such as nutrient deficiencies and behavioral disorders, since this kind of negative evidence is always supportive of the status quo, unless specific pathways and stresses can be identified which rather than correlate to one another, show conclusive cause effect relationships of nutrition deficiency and stress. All of these subject headings are good examples of how anthropologists have taken empirical examples of biological stresses hypothesized to result from, among other things, nutrient stress, and attempted to create explanations at various levels of the "adaptive domains", with varying levels of success.
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