Mechanical hypotheses concerning the function of chimpanzee anatomical specializations are examined in light of recent positional behavior data. Arm-hanging was the only common chimpanzee positional behavior that required full abduction of the humerus, and vertical climbing was the only distinctive chimpanzee positional behavior that required forceful retraction of the humerus and flexion of th...

Wild great apes often suffer from diseases of unknown aetiology. This is among the causes of population declines. Because human cytomegalovirus (HCMV) is an important pathogen, especially in immunocompromised individuals, a search for cytomegaloviruses (CMVs) in deceased wild and captive chimpanzees, gorillas and orang-utans was performed. By using a degenerate PCR targeting four conserved gene...

■ Abstract In the 1970s, researchers provided the first detailed descriptions of intergroup conflict in chimpanzees. These observations stimulated numerous comparisons between chimpanzee violence and human warfare. Such comparisons have attracted three main objections: (a) The data supporting such comparisons are too few, (b) intergroup aggression is the result of artificial feeding by observer...

OF A TOTAL OF 50 chimpanzees wild-captured in different O areas of the tropical iain forest in Gabon, two were found to be positive for HIV-1 antibodies.’ From one chimpanzee a lentivirus, sIv,z,ab, was isolated. As a result of virological and molecular studies it was classified as an HIV-l-related nonhuman Subsequently, another chimpanzee lentivhs, SIVEpz-mo has been isolated from a wild-captu...

Background: Humans detect faces with direct gazes among those with averted gazes more efficiently than they detect faces with averted gazes among those with direct gazes. We examined whether this ‘‘stare-in-the-crowd’’ effect occurs in chimpanzees (Pan troglodytes), whose eye morphology differs from that of humans (i.e., low-contrast eyes, dark sclera). Methodology/Principal Findings: An adult ...

Army ant predation by chimpanzees has been studied as an intriguing example of tool use and a possible case of cultural variation. However, the importance of army ant prey in chimpanzee diet and feeding ecology is still only poorly understood.We studied the availability and consumption of army ants in a population of the chimpanzee subspecies Pan troglodytes vellerosus in Nigeria. Army ants wer...

In spite of its evolutionary significance and conservation importance, the population structure of the common chimpanzee, Pan troglodytes, is still poorly understood. An issue of particular controversy is whether the proposed fourth subspecies of chimpanzee, Pan troglodytes ellioti, from parts of Nigeria and Cameroon, is genetically distinct. Although modern high-throughput SNP genotyping has h...

Chimpanzees and humans are genetically very similar, with the striking exception of their Y chromosomes, which have diverged tremendously. The male-specific region (MSY), representing the greater part of the Y chromosome, is inherited from father to son in a clonal fashion, with natural selection acting on the MSY as a unit. Positive selection might involve the performance of the MSY in spermat...

There is broad consensus among paleoanthropologists that meat-eating played a key role in the evolution of Homo, but the details of where, when, and why are hotly debated. It has been argued that increased faunivory was causally connected with hominin adaptation to open, savanna habitats. If savanna-dwelling chimpanzees eat meat more frequently than do forest chimpanzees, it would support the n...

Two chimpanzees, 1535 and 1536, became persistently infected following inoculation with RNA transcripts from cDNA clones of hepatitis C virus (HCV). Analysis of the HCV genomes from both animals showed an accumulation of amino acid substitutions over time. The appearance of substitutions in the envelope genes was associated with increased antienvelope antibody titers. However, extensive mutatio...