Avoiding Phylogenetic Bias

absence of viviparity or at least egg-retention in birds. And what drives research if not challenging mysteries? Moreover, the borderline between inventing adaptive stories and proposing hypotheses to generate testable predictions is not sharp. The book presents new ideas at the research frontier, which is one of its many merits. For instance, CluttonBrock argues that the potential reproductive rate determines which sex competes for access to the other sex, implying that if male potential reproductive rate is lower than female potential reproductive rate, females will compete for males'. What, then, is 'potential' reproductive rate? 'Potential' suggests something that is not realized due to constraints, but what exactly is that something? Access to mates and food supposedly should not constrain reproduction, but what about mating patterns such as monogamy: should an 'innate' reluctance or inability to mate with more than one partner count as a constraint? The concluding chapter attempts to answerthefive initial questions, or at least to point out current theoretical and practical difficulties in doing so. For take-home messages, this is a brilliant chapter. It ends with prospects for further theoretical and practical areas of research, as well as some suggestions as to what we should avoid doing! I found CluttonBrock's book stimulating and thought provoking, and strongly recommend it to anyone interested in breeding systems in general and parental care in particular.