Send to

Choose Destination
See comment in PubMed Commons below
Proc Biol Sci. 1997 Jul 22;264(1384):985-91.

Optimal killing for obligate killers: the evolution of life histories and virulence of semelparous parasites.

Author information

  • 1NERC Centre for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire, UK.


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 later 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.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk