Department of Entomology, Cornell University, Ithaca, New York, 14853.
Evolution. 2013 Oct;67(10):2982-98. doi: 10.1111/evo.12161. Epub 2013 Jun 7.
The evolution of parasitic behavior may catalyze the exploitation of new ecological niches yet also binds the fate of a parasite to that of its host. It is thus not clear whether evolutionary transitions from free-living organism to parasite lead to increased or decreased rates of diversification. We explore the evolution of brood parasitism in long-tongued bees and find decreased rates of diversification in eight of 10 brood parasitic clades. We propose a pathway for the evolution of brood parasitic strategy and find that a strategy in which a closed host nest cell is parasitized and the host offspring is killed by the adult parasite represents an obligate first step in the appearance of a brood parasitic lineage; this ultimately evolves into a strategy in which an open host cell is parasitized and the host offspring is killed by a specialized larval instar. The transition to parasitizing open nest cells expanded the range of potential hosts for brood parasitic bees and played a fundamental role in the patterns of diversification seen in brood parasitic clades. We address the prevalence of brood parasitic lineages in certain families of bees and examine the evolution of brood parasitism in other groups of organisms.
寄生行为的演化可能会促进新生态位的开拓，但也将寄生虫的命运与其宿主的命运联系在一起。因此，从自由生活的生物向寄生虫的进化是否会导致多样化率的增加或减少尚不清楚。我们探索了长舌蜂的育雏寄生行为的演化，并发现 10 个育雏寄生类群中有 8 个的多样化率降低。我们提出了育雏寄生策略的演化途径，并发现一个策略是寄生在封闭的宿主巢房中，由成年寄生虫杀死宿主后代；这代表了育雏寄生谱系出现的强制性第一步；最终演变成一个策略，即寄生在开放的宿主细胞中，由专门的幼虫龄期杀死宿主后代。向寄生开放式巢细胞的转变扩大了育雏寄生蜂的潜在宿主范围，并在育雏寄生类群的多样化模式中发挥了重要作用。我们探讨了在某些蜜蜂科中育雏寄生谱系的普遍性，并研究了其他生物群体中的育雏寄生演化。
