Behavior in Pan troglodytes Evolution of Primate Behavior
Introduction Pan troglodytes, also known as the common chimpanzee is a fascinating primate to observe. ... Unfortunately, our closest living ancestor, the common chimpanzee (Pan troglodytes) has not escaped our carelessness. ... troglodytes is in the Pongidae family, along with gorillas (Gorilla gorilla) and bonobos (P. ... troglodytes is found in a wide variety of African environments and range from moist forest to near desert like conditions (Dandelot in Meester and Setzer 1977) P. troglodytes is considered an endangered species. ... troglodytes conservation status is EN A2cd. ... troglodytes will likely be reduced by half with in the next 10 years because of such factors as decline of quality habitat and/or current levels of exploitation (IUCN 2001). ... troglodytes is the only closest living example of our past. ... One might think that with such complex behavior as eating leaves and shoots for medicinal purposes and hunting for food, that chimpanzees might have a very structured social organization. ... Mating Systems Mating systems are especially important in the study of animal behavior. ... (Pruetz & Bloomsmith 1995) This is one instance where the mating system helps predict the behavior of the male. ... There is currently controversy over this aspect of chimpanzee behavior. ... Living in large social groups gives chimpanzees the ability to attack other primate populations with few if any casualties. ... Dispersal and Altruism In 1971, Trivers, in an attempt to explain evolution of animal behavior, first proposed the idea of reciprocal altruism (Trivers 1971). ... If the donor continues with behavior that decreases his fitness, then the trait for altruism will not spread (Wilson, E. ... But reciprocal altruism is an act where the donor will also increase his fitness by expecting the same behavior (at a later date) from the recipient. Reciprocal altruism will only evolve as a societal behavior if the members of a society live for a long time, remember previous acts of altruism, and interact on a frequent and regular basis (Trivers 1971). ... (Wrangham 1975 from Moore 1984) In this event, the behavior would not be considered reciprocal altruism, because the possessor would not be giving up meat expecting meat in return; rather, he would be giving up meat merely to physically protect himself. While the topic of altruism in chimpanzees is focused here on hunting behavior, there are other reciprocally altruistic behaviors that are documented in chimpanzees. ... Focus on Evolution of Primate Behavior Many studies of chimpanzees focus on one particular aspect of their behavior, like tool usage or meat sharing, for example. The researchers will use their data to support or refute their hypotheses and will attempt to tie the behavior into an evolutionary framework. There is not a great amount of explanation though that ties every aspect of chimpanzee behavior into an evolutionary framework. Finding an explanation for the cause of primate social behavior is important, especially for chimpanzees. ... troglodytes is our closest living ancestor, understanding their behavior may give us insight into our own behavior. Three hypotheses attempt to explain the evolution of social behavior among chimpanzees. ... troglodytes also extends to behavior. ... 1975) the evolution of the social structure and behavior is based on the need to have a sense of self-being. ... Social structure helps them keep their ability to reason, so social behavior will evolve to strengthen the meta-relationship, but essentially for the good of the individual. ... In other words, chimpanzee behavior like strong mother-offspring bonding evolved into the strong parental bonds we have as humans. Eberhard (Eberhard 1975) does not take such a psychological view of the evolution of primate behavior. The hypothesis is that kin selection is primarily responsible for the evolution of primate behavior. She states, “…Hamilton’s idea of inclusive fitness – could serve as the basis for a general and comprehensive theory of social behavior capable of evaluating the selective significance of any social act…” (Eberhard 1975: 3) In chimpanzees the example of kin selection given in the framework of inclusive fitness is where young (primarily sexually inactive) chimpanzee males will aid dominant males in hunting.