[kc311v2]

I stumbled across an interesting article I thought you all might like to glance briefly at.

An excerpt taken from The Atlantic Monthly:

The Selfless Gene

...

Animals may begin to live together for a variety of reasons—most obviously, safety in numbers. In one of his most engaging papers, William Donald Hamilton observed that a tight flock, herd, or shoal will readily appear if every animal tries to make itself safer by moving into the middle of the group—a phenomenon he termed the "selfish herd". But protection from predators isn't the only benefit of bunching together. A bird in a flock spends more time eating and less time looking about for danger than it does when on its own. Indeed, eating well is another common reason for group living. Some predatory animals—chimpanzees, spotted hyenas, and wild dogs, for example—have evolved to hunt together.

Many social animals thus live in huge flocks or herds, and not in family groups—or even if the nexus of social life is the family, the family group is itself part of a larger community. In species such as these, social behavior must extend beyond a simple "Be friendly and helpful to your family and hostile to everybody else" approach to the world. At the least, the evolution of larger social groupings is accompanied by an increase in the subtlety and complexity of the ways animals get along together.

Consider baboons. Baboons are monkeys, not apes, and are thus not nearly as closely related to us as chimpanzees are. Nonetheless, baboons have evolved complex social lives. They live in troops that can number from as few as eight to as many as 200. Females live with their sisters, aunts, mothers, and infants; males head off to find a new troop at adolescence (around age 4). Big troops typically contain several female family groups, along with some adult males. The relationships between members of a troop are varied and complex. Sometimes two or more males team up to defeat a dominant male in combat. Females often have a number of male "friends" that they associate with (friends may or may not also be sex partners). If a female is attacked or harassed, her friends will come bounding to the rescue; they will also protect her children, play with them, groom them, carry them, and sometimes share food with them. If the mother dies, they may even look after an infant in her place.

Yet friendliness and the associated small acts of affection and kindness—a bout of grooming here, a shared bite to eat there—seem like evolutionary curiosities. Small gestures like these don't affect how many children you have. Or do they?

Among social animals, one potentially important cause of premature death is murder. Infanticide can be a problem for social mammals, from baboons and chimpanzees to lions and even squirrels, for example, the main cause of death for juveniles was other Belding's ground squirrels; at least 8 percent of the young were murdered before being weaned. Similarly, fighting between adults—particularly in species where animals are well armed with horns, tusks, or teeth—can be lethal, and even if it's not, it may result in severe injuries, loss of status, or eviction from the group.

The possibility of death by murder creates natural selection for traits that reduce the risk. For example, any animal that can appease an aggressor, or that knows when to advance and when to retreat, is more likely to leave descendants than an animal that leaps wildly into any fray. Which explains why, in many social-mammal species, you don't see many murders, though you do see males engaging in elaborate rituals to see who's bigger and stronger. Serious physical fights tend to break out only when both animals think they can win (that is, when they are about the same size).

Thus, among animals such as baboons, friendships mean more than half a bit of mutual scratching; they play a fundamental role in an animal's ability to survive and reproduce within the group. Friendships between males can be important in overcoming a dominant male—which may in turn lead to an improvement in how attractive the animals are to females. Similarly, females that have a couple of good male friends will be more protected from bullying—and their infants less likely to be killed. Why do the males do it? Males that are friends with a particular female are more likely to become her sex partners later on, if indeed they are not already. In other words, friendship may be as primal an urge as ferocity.

Sam Bowles, an economist turned evolutionary biologist who splits his time between the Santa Fe Institute, in New Mexico, and the University of Siena, in Italy, notes that during the last 90,000 years of the Pleistocene Epoch (from about 100,000 years ago until about 10,000 years ago, when agriculture emerged), the human population hardly grew. One reason for this was the extraordinary climatic volatility of the period. But another, Bowles suggests, was that our ancestors were busy killing each other in wars. Working from archaeological records and ethnographic studies, he estimates that wars between different groups could have accounted for a substantial fraction of human deaths—perhaps as much as 15 percent, on average, of those born in any given year—and as such, represented a significant source of natural selection.

Bowles shows that groups of supercooperative, altruistic humans could indeed have wiped out groups of less-united folk. However, his argument works only if the cooperative groups also had practices—such as monogamy and the sharing of food with other group members—that reduced the ability of their selfish members to out-reproduce their more generous members. (Monogamy helps the spread of altruism because it reduces the differences in the number of children that different people have. If, instead, one or two males monopolized all the females in the group, any genes involved in altruism would quickly disappear.) In other words, Bowles argues that a genetic predisposition for altruism would have been far more likely to evolve in groups where disparities and discord inside the group—whether over mates or food—would have been relatively low. Cultural differences between groups would then allow genetic differences to accumulate.

If Bowles' analysis is right, it suggests that individuals who could not conform, or who were disruptive, would have weakened the whole group; any group that failed to drive out such people, or kill them, would have been more likely to be overwhelmed in battle. Conversely, people who fit in—sharing the food they found, joining in hunting, helping to defend the group, and so on—would have given their group a collective advantage, and thus themselves an individual evolutionary advantage.

[MacosNerd]

My eyes glazed over after the first paragraph.

so is there a point to this post, or are you just posting the article

[ShortcutToMoncton]

This is the intarweb! We shouldn't be required to read! I demand a 3-sentence summary of all issues!

greg

[SpaceMonkey]

Awesome news for any of us who are stuck on a female baboon's "friends ladder." There is hope!

[shinji]

Just select it and use the Summarize service.

[RAILhead]

Here's how OS X summarizes it into one sentence:

If Bowles' analysis is right, it suggests that individuals who could not conform, or who were disruptive, would have weakened the whole group; any group that failed to drive out such people, or kill them, would have been more likely to be overwhelmed in battle.

[paul w]

can you provide a link to the article please? this is something i'd like to forward to someone.

[Sijmen]

Mmmmm, i think this theory doesn't work on us humans. Apart from our intelligence, there is a much wider choice of men for women these days. For a women to choose a friend as a mate goes against natural selection, she choses the weakest of the species; the ass-kisser, the loser, the lifeless one of the bunch. In other words: the Ladder Theory remains

[Chuckit]