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Insects’ “Giant Leap” Reconstructed by Founder of SociobiologyDecember 27, 2007
In an article in the January 2008 issue of BioScience, Edward O. Wilson argues for a new perspective on the evolution of advanced social organization in some ants, bees, and wasps. Wilson’s article surveys recent evidence that the high level of social organization called “eusociality,” found in some insects in the order Hymenoptera (and rarely in other species), is a result of natural selection acting on nascent colonies of species possessing features that predispose them to colonial life. Wilson concludes that these features--principally progressive provisioning of larvae and behavioral flexibility that leads to division of labor--allow the evolution of colonies that are maintained and defended because they are close to food sources. Eusociality is a challenge for biologists to understand because worker castes in eusocial species forgo reproduction themselves in order to rear young that are not their own, a behavior labeled “altruistic.” Wilson’s current view of eusociality differs from the assessment in his seminal book Sociobiology: The New Synthesis (1975). According to that widely accepted earlier opinion, natural selection acting on individuals that are related (kin selection), rather than on whole colonies, explains eusociality in the Hymenoptera. Kin selection is thought to be especially powerful in these animals because of an unusual genetic system, known as haplodiploidy, that they share. In his article in BioScience, Wilson examines the findings of a number of researchers and points out anomalies in the occurrence of eusociality that kin selection cannot easily explain. Eusociality has evolved only a few times in the history of life, and not always in haplodiploid species. Furthermore, the great majority of haplodiploid species are not eusocial. Wilson holds that group selection--which he defines as selection acting on emergent traits of the group as a whole--explains eusociality’s rare instances better than kin selection does. Kin selection, he writes, is “not wrong” but incomplete. Wilson’s view is controversial because theoretical biologists have thus far been unable to create mathematical models that demonstrate the strong colony-level selection that Wilson postulates. Any theory about eusociality has to explain why selection acting on individuals does not lead some of them to undermine the colony by producing offspring themselves. According to some of Wilson’s critics, the theory he now espouses amounts to a cryptic form of individual-level selection rather than true group selection. The January 2008 issue of BioScience includes a special section, "Managing for Resilience in Coastal Marine Ecosystems," which is detailed in a separate press release titled "Resilience Concepts Poised to Aid Management of Coastal Marine Ecosystems." In addition to the special section, the issue includes the following research articles: Nonnative Species and Bioenergy: Are We Cultivating the Next Invader? Transgene Escape Monitoring, Population Genetics, and the Law ContactJennifer Williams
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