…however, animals engage in apparent altruism (that is, they exhibit behaviour that increases the fitness of other individuals by engaging in activities that decrease their own reproductive success). For example, American zoologist Paul Sherman found that female Belding’s ground squirrels (Spermophilus beldingi) give staccato whistles that warn nearby conspecifics of…

…a good example of an altruistic behaviour. Why individuals give an alarm call to begin with is not necessarily obvious, since the act of calling may attract a predator and endanger the caller. In the Sierra Nevada mountains of California, Belding’s ground squirrels (Spermophilus beldingi) call more frequently when they…

…members’ interactions are of an altruistic nature. Examples of behaviours that appear to influence group selection include cooperative hunting, such as among lions and other social carnivores; cooperative raising of young, such as in elephants; and systems of predatory warning, such as those used by prairie dogs and ground squirrels.

…be derived from cooperation and altruistic behaviour. Inclusive fitness theory suggests that altruism among organisms who share a given percentage of genes enables those genes to be passed on to subsequent generations. In this way, an altruistic act that supports the survival of a relative or other individual theoretically enhances…

The apparent altruistic behaviour of many animals is, like some manifestations of sexual selection, a trait that at first seems incompatible with the theory of natural selection. Altruism is a form of behaviour that benefits other individuals at the expense of the one that performs the action;…

…role in the evolution of altruism, cooperation, and sociality; however, the term kin selection was coined in 1964 by British evolutionary biologist Maynard Smith.

…may behave in ways that benefit other members of the group at some cost or risk to themselves. Male baboons threaten predators and cover the rear as the troop retreats. Wolves and wild dogs take meat back to members of the pack not present at the kill. Gibbons and chimpanzees…

It explains apparently altruistic behaviour in some animal species as actually being genetically selfish, since such behaviours usually benefit closely related individuals whose genes resemble those of the altruistic individual. This insight helps explain why soldier ants sacrifice their lives in order to defend their colony, or why…

Thus, altruistic behaviour—as when an organism sacrifices itself in order to save other members of its immediate family—would seem incompatible with this process. In Sociobiology Wilson argued that the sacrifice involved in much altruistic behaviour results in saving closely related individuals—i.e., individuals who share many of…

of labour, cooperation, altruism, and a great many individuals aiding the reproduction of a relative few. The most widely recognized forms of social behaviour, however, involve interaction within aggregations or groups of individuals. Social behaviours, their adaptive value, and their underlying mechanisms are of primary interest to scientists…

…workers, who believed that such altruism should rarely evolve, Wynne-Edwards’s advocacy of this view prompted a careful reappraisal of the evolutionary basis of social behaviour that continues to this day.

>altruism (the altruist makes a sacrifice and the recipient benefits), selfishness (the actor benefits at the expense of the recipient), and spite (the actor hurts the recipient and both pay a cost). Mutualistic associations pose no serious evolutionary difficulty since both individuals derive benefits that…

A second solution for how altruism can evolve among unrelated individuals comes from a study in humans. In this study, individuals punished unrelated cheaters (altruistic punishment), even though they received no material benefit for doing so and were unlikely to interact with them in the future. Furthermore, there may be…

Many cetaceans exhibit epimeletic behaviour, in which healthy animals take care of another animal that has become temporarily incapacitated. This is evident when a wounded or sick whale is supported by others or in cases when a dolphin (usually the mother) pushes a dead calf around.

… outstanding problems: the evolution of altruism and the evolution of sexual reproduction. Hamilton’s work on the genetics of social behaviour inspired the sociobiology debate of the late 20th century.