Wednesday, November 19, 2008

E.O. Wilson Shifts His Position on Altruism in Nature

A cool article from the Boston Globe on Wilson's new(ish) stance regarding social pressures in evolution and the existence of altruism.

E.O. Wilson shifts his position on altruism in nature

In his new book, Edward O. Wilson says the widely accepted theory of kin selection doesn't explain the origin of altruism. In his new book, Edward O. Wilson says the widely accepted theory of kin selection doesn't explain the origin of altruism.
By Peter Dizikes Globe Correspondent / November 10, 2008

It is a puzzle of evolution: If natural selection dictates that the fittest survive, why do we see altruism in nature? Why do worker bees or ants, for instance, refrain from competing with those around them, but instead search for food or build nests on behalf of their companions? Why do they sacrifice their own reproductive success for the good of the group?

In the 1960s, British biologist William Hamilton offered an explanation in a theory now called kin selection. When animals, often insects, help siblings or other relatives survive, they are enhancing the odds that their shared family genes will be passed on. In other words, the genes, not the individual or social group, are what counts in evolution.

Hamilton's idea was eventually accepted by most biologists, and found an enthusiastic backer, at the time, in Edward O. Wilson, the renowned Harvard evolutionist.

That was then. Now, Wilson has changed his mind, startling colleagues by arguing that kin selection does not lead to altruism.

Kin selection is a scientific crutch, a "very seductive" idea that "doesn't tell us anything decisive about how altruism originated," Wilson says. He adds: "We need a whole new way of explaining things."

He has one. Wilson posits that altruism evolved due more to ecological circumstances than the influence of genes.

In his new book "The Superorganism," out today, Wilson and his co-author, Bert Holldobler, argue that natural selection operates on the group, not just the gene. The lavishly-illustrated volume examines the complex systems that help insect societies survive, from an intricate array of communication signals to the elaborate architecture of nests. But Wilson - though not Holldobler - goes further, saying altruism occurs not because animals share family ties, but because certain altruistic acts have become useful for the overall survival of insect groups.

"The close kinship of the members of these groups is a consequence, not a cause, of their evolution," says the ever-genial Wilson in an interview at his home in Lexington. He believes altruistic (or eusocial) societies developed in ecological conditions where food was plentiful enough to allow insects to practice "progressive provisioning," in which a mother leaves its offspring with food, as some wasps or bees do. This creates a need for others in the insect society to stand guard over the young.

Given these conditions, Wilson postulates, an insect group experiencing a single beneficial genetic mutation - such as the ability to distinguish nest mates from outsiders, a trait many insects possess - might adopt altruism as a useful social behavior.

Many biologists emphatically disagree.

Read the whole article.


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