Skew Selection: Nature Favors a Trickle-Down Distribution of Resources in Ants

Synopsis: According to skew selection, ant queens are neither ruthlessly selfish nor blindly altruistic; they are shrewd investors. The goal of shrewd investors is not to win the game, but to continue play over evolutionary time. Skew selection describes a set of investment strategies employed by players such as ant queens to keep the game going. First, ant queens acquire excess resources—more than they need for immediate survival and reproduction. Second, queens invest a portion of their excess resources in personal capital to maintain dominant status. Third, queens also invest a portion of excess resources in low-quality offspring to gain group capital. Fourth, when investing in group capital, resources are distributed in a trickle-down fashion to maintain the largest number of diminishing-quality offspring possible. The trickle-down redistribution allows the shrewd queen to increase group size (safety in numbers) and, at the same time, maintain individual status (safety in position). According to skew selection, queens invest in low-quality offspring (sterile workers) to buffer hereself and her high-quality offspring from agents of death such as war, predation or disease. This revised version was published online in July 2006 with corrections to the Cover Date.