BOOK REVIEWS 825

The Origins of Human Social Relations. Edited by H, R. SCnAFFER. Pp. 297. London and New York: Academic Press (1971). Price s

This report of a study group contains fourteen papers concerned with early social development. Although only three are concerned specifically with animals, nearly all are relevant to readers of this journal. Rosenblum reviews the studies by Kaufman and himself on mother- infant relations in bonnet and pig-tailed macaques and in squirrel monkeys: his chapter includes interesting data on the cohesiveness of family units and on the depressive symptoms produced in infant monkeys by intermittent exposure to their mothers during prolonged separation from them. Van Lawick-Goodall presents some new data on mother-infant relations in free-living chimpanzees, including descriptions of the behaviour of infants whose mothers died, and J. P. Scott compares early social development in man and dog. To mention but two of the studies of children, the work of Ainsworth and her colleagues on the behaviour of 1-year-olds in a strange situation involves a method for tackling the bases of individual differences in behaviour, a problem too often neglected by students of Animal Behaviour; and that by Schaffer (who edited the volume) on cognitive structure contains an interesting discussion on the relevance of studies of imprinting to problems of human develop- ment.

ROBERT A. HINDE M.R.C. Unit on the Development and Integration of Behaviour University of Cambridge

A Primer of Population Biology. By. EDWARD O. WILSON WILLIAM H. BOSSERT. Stamford: Sinauer Associates

Inc. (1971). Price $3.95. The logistic curve seems destined to be interminably oversold as an ecological model. Wilson and Bossert's excellent introduction to population genetics, population ecology, and theoretical biogeography is, unfortunately, no exception, despite the authors ' clearly stated intro- ductory qualification that all statements made in popu- lation models must be recognized as oversimplifications. We take strong exception to the statement on page 103 that the logistic equation 'does give a reasonably good fit to many case histories of population growth observed in both the laboratory and the field.' Growing populations almost always overshoot their eventual equilibrium level, even where the hypothetical carrying capacity of the environment is not varying continually, as it almost always is. This fact is about to become painfully obvious for our own species and in this context the comforting equilibration visualized by the logistic model is almost pernicious.

Further problems of this sort arise with respect to extensions of the logistic model. There is no discussion of the assumptions underlying the Lotka-Volterra equations and students are unlikely to appreciate that these models apply only to a single predator-prey pair in a constant environment, rather than to complex and variable ecosystems.

Complaints of this sort aside, the Primer is really an outstanding textbook. It is effectively designed for self- teaching, with problems that can be worked to confirm the reader's understanding as he progresses. The treat- ment of subjects of current theoretical interest is especially noteworthy. Such topics as the problem of genetic load,

Levin's idea of 'fitness sets,' the Shannon-Weiner diversity index, and the theory of species equilibrium in island isolates are all discussed. Both the neophyte and the mature investigator brushing up on fields peri- pheral to his own specialization will find the presentations of classic and current theories remarkably clear and stimulating.

Hopefully, one effect of this text will be to encourage ethologists to turn their attention to the role of behaviour in evolutionary processes. There are huge gaps in both qualitative and quantitative aspects of our understanding of how behaviour influences genetic variance, gene flow, and the evolutionarily effective size of populations. Similar opportunities exist with respect to community ecology and species equilibrium theory, although the discussion is perhaps tess stimulating. Thoughtful reading of the Primer will make these opportunities for significant behavioural research very apparent.

On the negative side there are several points where even as fine an effort as this has considerable room for improvement. The concept of the Poisson distribution is introduced without explanation sufficient for the first year student. The significance of genetic drift seems to us to be greatly underemphasized, and the resolution (p. 73) of the dilemma of genetic load, posed by Hubby and Lewontin, is too pat to be very reassuring. In the discussion of energy flow in ecosystems the role of de- composers, relative to that of predators, is consistently underemphasized (see pp. 129 and 149). As we have in- dicated, the heterogeneity of the environment in space and time could have been more strongly emphasized, thus keeping the current state of the modeler's art in good perspective. It might also have been helpful to have some discussion of how the newer theories may help to close the gap between ecology and population genetics. Is there a relationship, for example, between 'fitness sets' and the Hutchinson niche theory ?

While the senior reviewer is heartened to see a dis- tinction between ' r ' and 'rmax' made on page 97, he feels that the utility of the concept of rate of increase would be considerably improved if the term 'intrinsic rate of natural increase' could be reserved for 'r,,a~' (the capability of a population to increase in a hypo- thetical ideal situation) while ' r ' were defined simply as 'rate of change'.

The suggestions for additional readings are good, but highly selective and might well have included a few references to works of such 'heretics' as Andrewartha and Birch, and such specialists as David Lack. I t would have also been useful to have included references which could lead the reader to relate the topics discussed in this text to the question of speciation as seen by the sys- tematist.

A Primer of Population Biology has noble objectives and meets them extremely well. We recommend it highly, as review reading for investigators, as an adjunct to courses in behaviour and as an introduction to courses in population genetics, population ecology, population biology, and (if there is such a field) population ethology.

PAUL K. ANDERSON PAUL H. WmTNEY

Department of Biology, The University of Calgary, Calgary, Alberta