Harmony and Conflict in the Living World - Alexander F. Skutch [15]
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their species may harm it by overburdening the habitat and causing widespread starvation. Even in beneficial activities, moderation is needed.
Apart from mutations that might arise in its reproductive tissues, the genes an organism bears are not peculiarly its own but were inherited from its forebears, which are seen to be more numerous the farther backward in time we trace its ancestry. The more these genes contribute to the quality of the individual and the survival of its race, the more their bearer serves its species by transmitting to posterity this endowment which, in a sense, it holds in trust for future generations.
An animal may serve its species without assisting its contemporaries, or it may aid them without benefit to its species, as is particularly evident in human society, where philanthropy or charity, no less than medical aid, may have highly dysgenic consequences. Beneficence too often helps incompetent individuals with heritable defects not only to survive but to beget children who are likely to receive the undesirable traits of their parents, thereby deteriorating the human stock. We value the impulse to help the unfortunate, while we deplore consequences that might be avoided if those with genetic defects who are made comfortable by public or private assistance could be restrained from reproduction; if they desire children, they might adopt one or two. Animals in a state of nature commonly lack the surplus of energy and resources to succor less fortunate or less well endowed individuals, nor can they afford to weaken their species by diluting its gene pool with inferior genes. Failure to distinguish behavior beneficial to the species from that which aids individuals most in need of support has led certain biologists to exaggerate the selfishness of animals, or of the genes that determine their behavior.
Some animals act in ways that are excessively brutal, as when male lions or langurs destroy the suckling young of a female wrested from another male, so that the mother may the sooner become pregnant with the winner's progeny; or when a victorious human tribe massacres all the males and pregnant females among its captives, retaining the virgins to bear children for their captors, as
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happened when the Israelites, at the command of their leader, Moses, overcame the Midianites (Numbers 31).
Such harshness has rarely been recorded in the animal world. More widespread is the mitigation of conflict by ritualization, especially among birds, which tend to settle disputes by posturing and calling rather than by fighting. At territorial boundaries, howling monkeys of tropical American forests confront their neighbors with stentorian voices that obviate physical clashes. Or if fighting becomes serious, the losing animal may save itself by assuming a submissive posture that pacifies its opponent, as happens among wolves, turkeys, and gulls. Natural selection should promote all behavior that abbreviates or avoids conflicts that needlessly squander the contestants' energy and expose them to predation while they struggle, heedless of what is happening around them. Few species are so firmly established that they can afford to lose many members in intraspecific strife. Predation and parasitism, far more than competition between individuals of a species, make nature harsh and bloody.
Many animals increase their safety by joining in flocks or herds, composed of one or more species. Although mixed flocks of birds foraging through tropical woodland are conspicuous, many keen eyes and voices ready to sound the alarm make them difficult for a predator to approach undetected. By joining such flocks, a bird apparently