Evolution.

Society for Experimental Biology

Date:: 1953

Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Evolution. Source: Wellcome Collection.

454/484 (page 422)

424 SOCIAL BEHAVIOUR AND PRIMATE EVOLUTION must by far outweigh any negatives present. Otherwise on his interpre¬ tation the spatial relations would be different. Carpenter considers the presence of the negative and positive elements to be general. This is true. The unique element of primate society, however, appears to be the persistent interaction between negative and positive elements in the trigonal sphere of the primate social environment, which is thereby distinguished from other mammalian environments. In the life of baboons and macaques at least this conflict is an ever- present element requiring reassessment from moment to moment, during active foraging activities for example (Zuckerman, 1932). (c) The evolutionary significance of the behaviour of the subordinate male The forces operating in the trigonal situation can, we have seen, be deduced from the existence of equilibration behaviour which provides a means of avoiding unpremeditated fights with dominant males. We should, therefore, expect to find that the behaviour of animals in this region is conspicuous by the absence of fights. Carpenter (private communication) concludes that this is so in the Santiago Rhesus Colony. Much of the constantly operative social control of individual over individual, and individuals over individuals, is exercised in groups through sign-signal communication. Not only individuals as such, but also their statuses are evidently perceived as signalised and appropriately responded to by most other individuals of organised groups. For example, it is a significant fact that the supremely dominant males of all groups of the Santiago Colony fought other group members less frequently than the males subordinate to them. The supreme males were often without disfiguring injuries. They were sleek of coat and full in flesh. Their stances, postures, carriage, especially the upward flexed tails, seemed to function as signs of their statuses, rights and privileges relative to other animals of their groups. Only infrequently did the need arise to reinforce their statuses by actual fighting. When this became necessary, it was done with telling effect. Whereas due deference is shown for animals with high statuses, weak, sickly or cringing animals may be attacked repeatedly by a wide range of the group's members. Awareness of these elements is required of the subordinate male, and to some extent by the non-oestrous female, even when their behaviour is primarily directed towards the satisfaction of other needs besides mating. This is by virtue of the danger that is involved in too close an approach (be it undirected) to the trigonal sphere. It is unlikely that any other mammals (except some species of seals in the mating season) are subject to anything like such persistent threat in their normal environment ; certainly not to such persistent conflict. The above spatial analysis of the relations between members of primate