Herre E A
Science. 1993 Mar 5;259(5100):1442-5. doi: 10.1126/science.259.5100.1442.
It is often assumed that parasitic and disease-producing organisms tend to evolve benign relationships with their hosts over time. In contrast, theoretical arguments suggest that increased opportunities for parasite transmission will promote the evolution of increased virulence. The natural history of species-specific nematodes that parasitize fig-pollinating wasps permits the testing of these predictions in natural populations. For 11 species of Panamanian fig wasps, those species characterized by population structures that result in increased opportunities for parasite transmission harbor more virulent species of nematodes. In addition, differences in population structure are also associated with differences in other intra- and interspecific phenomena, including sex ratios among the fig wasp species, the degree of tension in the wasp-fig mutualism, and lethal combat among the males of parasitic wasps.
人们常常认为，随着时间的推移，寄生性和致病生物体往往会与宿主形成良性关系。相比之下，理论观点表明，寄生虫传播机会的增加将促进毒力增强的进化。寄生于榕小蜂的物种特异性线虫的自然史使得在自然种群中对这些预测进行检验成为可能。对于11种巴拿马榕小蜂而言，那些具有导致寄生虫传播机会增加的种群结构特征的物种，寄生着毒性更强的线虫物种。此外，种群结构的差异还与其他种内和种间现象的差异相关，包括榕小蜂物种间的性别比例、榕蜂共生关系中的紧张程度以及寄生蜂雄性之间的致命争斗。
