Human Adaptation (review)

This reprinted, edited volume addresses the complexity of the concept of adaptation and the difficulties in its application at different levels (e.g., individual level, population level, and species level). While the various authors discuss the potential pitfalls in the study of adaptation, it is generally agreed that this is an important concept within anthropology, since it represents a nexus among human biology, cultural process, and social organization. Furthermore, adaptations involving cultural and social behaviors are largely seen as being responsible for the flexibility found in human beings and for our success as a species. By comprehending long- and short-term adaptation and adaptability, anthropology as a discipline can make a significant contribution to the understanding of the links between biological and sociocultural processes.

Human Adaptation is divided into four chapters that review the state of knowledge on genetic, physiological, behavioral, and cultural adaptation. While the chapters are generally organized in a uniform format, they are not always tied together well. This problem is somewhat offset by the excellent and newly published preface by the editors, which nicely builds a theme and links together the different types of adaptation discussed in the respective chapters.

In the preface, H. Morphy and G.A. Harrison begin by pointing out the tendency to confuse adaptation in a causal sense and the fact that, as a highly flexible species, humans have the capacity to adjust to changing environments. In other words, human beings are preadapted and have the capacity to respond to changing environmental conditions. It is not necessarily the environmental change that causes the adaptation, but rather a preexisting adaptation that is exploited by changing circumstances (e.g., preadaptations for living at high altitudes).

Other epistemological and historical nuances with regard to the adaptation concept are discussed throughout the volume; for example, our inability to measure adaptation at the species level and our limited successes in detecting natural selection (e.g., the sickle cell case). There is also the sometime problematic issue of communication between biological and sociocultural anthropologists. While the former do not always appreciate the importance of factors such as social organization on human evolutionary biology, the latter sometimes fail to see how long-term biological processes can influence social organization and cultural processes.

In spite of these concerns, the prevailing message in Human Adaptation is that the concept of adaptation is important in anthropology and that more collaborative research needs to be done. The chapters in this volume discuss the ways in which adaptation can be applied in social, cultural, and biological anthropology.

In chapter 1 M.T. Smith examines the extent to which the human genetic endowment is adaptive, specifically focusing on the influence of natural selection and the relative fitness of genetic attributes. In his review of the literature, Smith examines different lines of evidence for natural selection, including demographic measures (e.g., differential fertility); body form, skin color; ecogenetics and pharmacogenetics (e.g., the persistent adult intestinal lactase and phenylthiocarbamide). In addition, he looks at evidence of blood group distributions, linguistic and genetic affinities, and the relationship between genetic markers and disease (e.g., TB and malaria). Smith concludes that the problem of sample size in demographic studies clouds our ability to draw any firm conclusions on genetic adaptation, but that the comparison of mother-offspring phenotypes and molecular studies will bring new insights.

G.A. Harrison discusses physiological adaptation in chapter 2 and points out that a framework of human physiology is built upon the concept of adaptation and adaptability. While physiologists have mostly focused on the mechanisms of adaptability in response to climate, infection, nutrition, and stress, they have not spent as much time looking at the biological effects of these mechanisms or at the variability of these effects. More attention needs to be given to these issues, especially when considering the long-term evolutionary implications of physiological variations.

In chapter 3, R.I.M. Dunbar focuses on whether or not behavior is adaptive in any biological sense. Does an individual's behavior maximize genetic...