Biology 1001A Lecture 21: Lecture 21 Arms Races.docx
Document Summary
E. g. ants eat plant but also protect it from bigger predators (both plant and ant gains: competing for access to limiting resource, one species fitness is reduced due to presence of another, e. g. trees competing for light (taller trees win, shorter trees have reduced fitness) There is correlation between degree of harm to host and transmission from one host to next: cost of high virulence: less reproductive success, benefit of high virulence: increases ability to spread to other hosts, e. g. hiv virulence will make many virions, kill host quickly then jump to another in this case benefits>cost. Malaria parasite doesn"t affect insect but instead affects only the human host: high host density: lots of hosts in small area, optimal virulence is high (can jump between humans easily, low host density: protection against disease will decrease optimal virulence, more success for virus if host is kept alive, ecology: changing ecology in our favour e. g. protection against malaria using mosquito nets.
