Lehmann Laurent, Ravigné Virginie, Keller Laurent
Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA.
Proc Biol Sci. 2008 Aug 22;275(1645):1887-95. doi: 10.1098/rspb.2008.0276.
Because it increases relatedness between interacting individuals, population viscosity has been proposed to favour the evolution of altruistic helping. However, because it increases local competition between relatives, population viscosity may also act as a brake for the evolution of helping behaviours. In simple models, the kin selected fecundity benefits of helping are exactly cancelled out by the cost of increased competition between relatives when helping occurs after dispersal. This result has lead to the widespread view, especially among people working with social organisms, that special conditions are required for the evolution of altruism. Here, we re-examine this result by constructing a simple population genetic model where we analyse whether the evolution of a sterile worker caste (i.e. an extreme case of altruism) can be selected for by limited dispersal. We show that a sterile worker caste can be selected for even under the simplest life-cycle assumptions. This has relevant consequences for our understanding of the evolution of altruism in social organisms, as many social insects are characterized by limited dispersal and significant genetic population structure.
由于种群粘性增加了相互作用个体之间的亲缘关系，因此有人提出种群粘性有利于利他性帮助行为的进化。然而，由于它增加了亲属之间的局部竞争，种群粘性也可能成为帮助行为进化的一个阻碍。在简单模型中，当帮助行为发生在扩散之后时，亲属选择的帮助行为所带来的繁殖力益处会被亲属之间竞争加剧的成本完全抵消。这一结果导致了一种广泛的观点，尤其是在研究社会生物的人群中，即利他行为的进化需要特殊条件。在这里，我们通过构建一个简单的种群遗传模型来重新审视这一结果，在该模型中我们分析有限扩散是否能够选择出不育工蚁阶层（即利他行为的极端情况）的进化。我们表明，即使在最简单的生命周期假设下，不育工蚁阶层也能够被选择出来。这对于我们理解社会生物中利他行为的进化具有重要意义，因为许多社会性昆虫的特点是扩散有限且具有显著的遗传种群结构。
