a . “... the existence of altruism between different species—which is not uncommon—remains an obstinate enigma.” Taylor, p. 225.
u Some inherited behavior is harmful to the animal but beneficial to unrelated species. For example, dolphins sometimes protect humans from deadly sharks. Many animals (goats, lambs, rabbits, horses, frogs, toads) scream when a predator discovers them. This increases their exposure but warns other species.
b . From an evolutionist’s point of view, a very costly form of altruism occurs when an animal forgoes reproduction while caring for another individual’s young. This occurs in some human societies where a man has multiple wives who share in raising the children of one wife. More well-known examples include celibate individuals (such as nuns and many missionaries) who devote themselves to helping others. Such traits should never have evolved, or if they accidentally arose, they should quickly die out.
Adoption is another example.
From a Darwinian standpoint, going childless by choice is hard enough to explain, but adoption, as the arch-Darwinist Richard Dawkins notes, is a double whammy. Not only do you reduce, or at least fail to increase, your own reproductive success, but you improve someone else’s. Since the birth parent is your rival in the great genetic steeplechase, a gene that encourages adoption should be knocked out of the running in fairly short order. Cleo Sullivan, “The Adoption Paradox,” Discover, January 2001, p. 80.
Adoption is known even among mice, rats, skunks, llamas, deer, caribou, kangaroos, wallabies, seals, sea lions, dogs, pigs, goats, sheep, bears, and many primates. Altruism is also shown by some people who have pets—a form of adoption—especially individuals who have pets instead of having children.
u Humans, vertebrates, and invertebrates frequently help raise unrelated young of others.
... it is not clear that the degree of relatedness is consistently higher in cooperative breeders than in other species that live in stable groups but do not breed cooperatively. In many societies of vertebrates as well as invertebrates, differences in contributions to rearing young do not appear to vary with the relatedness of helpers, and several studies of cooperative birds and mammals have shown that helpers can be unrelated to the young they are raising and that the unrelated helpers invest as heavily as close relatives. Tim Clutton-Brock, “Breeding Together: Kin Selection and Mutualism in Cooperative Vertebrates,” Science, Vol. 296, 5 April 2002, p. 69.
Six different studies were cited in support of the conclusions above.
c . “Ultimately, moral guidelines determine an essential part of economic life. How could such forms of social behavior evolve? This is a central question for Darwinian theory. The prevalence of altruistic acts—providing benefits to a recipient at a cost to the donor—can seem hard to reconcile with the idea of the selfish gene, the notion that evolution at its base acts solely to promote genes that are most adept at engineering their own proliferation. Benefits and costs are measured in terms of the ultimate biological currency—reproductive success. Genes that reduce this success are unlikely to spread in a population.” Karl Sigmund et al., “The Economics of Fair Play,” Scientific American, Vol. 286, January 2002, p. 87.
d . Some evolutionists propose the following explanation for this long-standing and widely recognized problem for evolution: “Altruistic behavior may prevent the altruistic individual from passing on his or her genes, but it benefits the individual’s clan that carries a few of those genes.” This hypothesis has five problems—several are fatal.
v Observations do not support it. [See Clutton-Brock, pp. 69–72.]
v “... altruistic behavior toward relatives may at some later time lead to increased competition between relatives, reducing or even completely removing the net selective advantage of altruism.” Stuart A. West et al., “Cooperation and Competition between Relatives,” Science, Vol. 296, 5 April 2002, p. 73.
v If individual X’s altruistic trait was inherited, that trait should be carried recessively in only half the individual’s brothers and sisters, one-eighth of the first cousins, etc. The key question then is: Does this “fractional altruism” benefit these relatives enough that they sire enough children with the altruistic trait? On average, one or more in the next generation must have the trait, and no generation can ever lose the trait. Otherwise, the trait will become extinct.
v From an evolutionist’s perspective, all altruistic traits originated as a mutation. The brothers, sisters, or cousins of the first person to have the mutation would not have the trait. Even if many relatives benefited from the altruism, the trait would not survive the first generation.
v The hypothesis fails to explain altruism between different species. Without discussing examples that require a knowledge of the life patterns of such species, consider the simple example above of humans who forgo having children in order to care for animals.
u Edward O. Wilson, an early proponent of this evolutionary explanation for altruism, now recognizes its failings.
I found myself moving away from the position I’d taken 30 years ago, which has become the standard theory. What I’ve done is to say that maybe collateral kin selection is not so important. These ants and termites in the early stages of evolution—they can’t recognize kin like that. There’s very little evidence that they’re determining who’s a brother, a sister, a cousin, and so on. They are not acting to favor collateral kin. Edward O. Wilson, “The Discover Interview,” Discover, June 2006, p. 61.
u “... in a pair of studies researchers show that chimpanzees will give up a treat to help out an unrelated chimp, and that chimps in the wild choose to go out on risky patrols to protect others, even when they aren’t their own kin.” “Chimps Show Signs of Altruism,” Science, Vol. 356, 23 June 2017, p. 1215.