摘要:

The absence of conspicuous sexual signals in some primates, particularly humans and vervets, has been interpreted as evidence that females of these species are ‘concealing’ ovulation from males. This conclusion is unjustified: the null hypothesis of no adaptation, that the absence of conspicuous sexual signals has resulted from the absence of selective pressures maintaining such adaptations, is both more parsimonious and better fits the facts. The related suggestion that there has been adaptation among females to conceal ovulation from their own consciousness is also unjustified. What, then, maintains sexual signals in those species that do have them? Many proposed hypotheses for the function of sexual signals do not account for their most puzzling feature: their conspicuousness. According to current theory on the evolution of communication, two explanations seem most plausible: conspicuous sexual signals function to communicate to distant receivers and/or to convince reluctant receivers. There is some empirical support for both hypotheses, but not overwhelming support for eit

ISSN:0015-5713    

DOI:10.1159/000156600

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156601

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The relationship between basal metabolic rate (BMR), body weight and diet is examined for primates. Contrary to the results reported in several recent works, there is no strong evidence that diet is directly linked to BMR, although a low BMR, relative to body weight, may be found in species with folivorous diets. There is some evidence that nocturnal haplorhine species have a relatively low BMR, but strepsirhines appear to have a uniformly low relative BMR regardless of their primary activity period. The evolution of BMR in primates is discussed in the light of these findings. Some predictions are made about the relative BMRs that should be found for other species whose BMR is, as yet, unknown.

ISSN:0015-5713    

DOI:10.1159/000156602

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Food handouts to Macaca thibetαnα at Mt. Emei have had dramatic consequences for both man and monkey as tourism has increased over the last decade. Food handouts and human submissive behaviour facilitate beg-robbing by the monkeys, which can be regarded as a mixed conditioning chain. Because of their lack of understanding of primate behaviour and resulting inappropriate responses, many visitors have lost possessions and have been severely frightened or even injured; in fact there have been 10 deaths as an indirect result over that past 8 years. The appropriate human response proved to be the display of dominance to maintain a distance from a beg-robbing monkey. Road-ranging macaques have also been injured or killed by visitors to obtain meat or bones or merely for amusement. Attempts should be made to eliminate the negative effects of food handouts by increasing visitors’ awareness of behavioural and ecological aspects and through aversive conditioning of the macaq

ISSN:0015-5713    

DOI:10.1159/000156603

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Numerous dental remains of Nannopithex zuccolae, n. sp., from the terminal early Eocene locality of Prémontré (Aisne), France, show the lower anterior dentition to be similar to that of other Nannopithex. Similarities include enlarged I1, reduced I2, reduced lower canine, loss of P2, small P3 and large P4. Upper molars, P3 and P4 all present primitive characters, making this species the most primitive as well as the oldest known microchoeri

ISSN:0015-5713    

DOI:10.1159/000156604

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156605

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156606

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156607

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156608

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156609

出版商:S. Karger AG    

年代:1992

数据来源: Karger