Optimal killing for obligate killers: The evolution of life histories and virulence of semelparous parasites
Optimal killing for obligate killers: The evolution of life histories and virulence of semelparous parasites
复制标题
DOI：
10.1098/rspb.1997.0136
复制
发表时间：
1997-07-22
影响因子：
4.7
通讯作者：
Weisser, WW
中科院分区：
文献类型：
--
作者：
Ebert, D;Weisser, WW
许多无脊椎动物的病毒、细菌和原生动物寄生虫首先在宿主内部繁殖，不释放任何传播阶段，然后杀死宿主，同时释放所有传播阶段。假设寄主内的生长依赖于密度，对这些必须杀死的寄生虫的生活史和毒力进化进行了建模。我们发现，当寄生虫的人均增长率下降到宿主死亡率的水平时，寄生虫应该杀死宿主。寄生虫应该在携带能力K较高时较晚杀死宿主，但在非寄生虫非寄主死亡率增加或寄生虫出生率较高时较早杀死它。当寄生虫生长的K(T)在感染过程中不是恒定的，而是随时间增加时，寄生虫应该在携带能力增长速度强烈减速的阶段附近杀死宿主。在K(T)与寄主大小有关的情况下，这种生长减速是在寄主成熟前后。
Many viral, bacterial and protozoan parasites of invertebrates first propagate inside their host without releasing any transmission stages and then kill their host to release all transmission stages at once. Life history and the evolution of virulence of these obligately killing parasites are modelled, assuming that within-host growth is density dependent. We find that the parasite should kill the host when its per capita growth rate falls to the level of the host mortality rate. The parasite should kill its host lat er when the carrying capacity, K, is higher, but should kill it earlier when the parasite-independent host mortality increases or when the parasite has a higher birth rate. When K(t), for parasite growth, is not constant over the duration of an infection, but increases with time, the parasite should kill the host around the stage when the growth rate of the carrying capacity decelerates strongly. In case that K(t) relates to host body size, this deceleration in growth is around host maturation.