Lipsitch Marc, Herre Edward Allen, Nowak Martin A
Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, England.
Evolution. 1995 Aug;49(4):743-748. doi: 10.1111/j.1558-5646.1995.tb02310.x.
Structure in a population of host individuals, whether spatial or temporal, can have important effects on the transmission and evolutionary dynamics of its pathogens. One of these is to limit dispersal of pathogens and thus increase the amount of contact between a given pair or within a small group of host individuals. We introduce a "law of diminishing returns" that predicts an evolutionary decline of pathogen virulence whenever there are on average more possibilities of pathogen transmission between the same pair of hosts. Thus, the effect of repeated contact between hosts will be to shift the balance of any trade-off between virulence and transmissibility toward lower virulence.
宿主个体群体中的结构，无论是空间结构还是时间结构，都可能对其病原体的传播和进化动态产生重要影响。其中一个影响是限制病原体的传播，从而增加给定的一对宿主个体之间或一小群宿主个体内部的接触量。我们引入了一条“收益递减定律”，该定律预测，只要同一对宿主之间平均存在更多病原体传播的可能性，病原体毒力就会出现进化性下降。因此，宿主之间反复接触的效果将是把毒力和传播性之间任何权衡的平衡转向更低的毒力。
