Altruism is a necessary component of natural selection, as those with the most potential fitness will benefit by help from those with the least potential fitness.
Kinship plays an important and pervasive role in the lives of humans and other animals, and chimpanzees are frequently used to illustrate the effects of kinship on primate social behavior. Among chimpanzees, long-lasting bonds form between mothers and their offspring, while related males in the same social group cooperate together in competition with males from other communities (Goodall, 1986). At Gombe, male chimpanzees who affiliate and cooperate frequently are not closely related through the maternal line, but rather were acquaintances during their youth. Chimpanzees live long lives and reproduce slowly, with high infant and juvenile mortality rates. Thus, the probability is low that females will give birth successively to sons who will reach adulthood together. Instead of forming selective bonds with maternal brothers, male chimpanzees cultivate social relationships opportunistically with members of their same age cohort and those of similar dominance rank. These individuals represent particularly attractive social partners because they grow up together, are generally familiar with each other, and are likely to share similar social interests and power throughout their lives (Goodall, 1986). And thus, it is from these groups which adult males form their kinship and hunting groups. .
Hunting is a basic trait that for many living creatures is a means of survival. Jane Goodall observed the tendency of male chimpanzees to do a majority of the hunting, most of which takes place in groups. Although females occasionally do hunt, adult and adolescent males make over ninety percent of the kills. Chimpanzees hunt small mammals including, monkeys, bush pig and small antelope. In the Gombe, chimpanzees tend to hunt when the opportunity arises, with an unexpected encounter of their prey.
