Coevolution Flashcards
What is coevolution?
reciprocal evolution where change in one species cause change in another species (and vice versa) over evolutionary time
What is coadaptation?
reciprocal adaptation (shorter time scale than coevolution)
what is cospeciation?
speciation in one lineage causes speciation in another lineage
What are the effects of coadaptation
- character displacement: similar species extentuate different traits to fill up differnent niches
- arms race
- coevolutionary cycles
what causes coadaptation to occur
- competition
- predation
- parasitism
- mutalism & symbiosis
what is tight coevolution?
coadaptation of one species with another species
what is diffuse coevolution
coadaptation between one species and lots of other species e.g. plant and herbivores
How does competition drive coadaptation?
similar spp. avoid competition by extentuating different traits, thus occupy different niches and increase chances of survival
How does predation drive coadaptation?
- prey evolve to avoid being eaten
- predator evolve to be better at eating prey
- diffuse coevolutionary arms race between predator and prey
- e.g. shell thickness of molluscs over geological time
How does parasitism drive coevolution?
- Parasites selected to infect common host genotype
- Hosts selected to be resistant to common parasite genotype
- arms race between parasite and host
- coevolutionary cycle due to negative frequency dependency (more host => more parasite, less host => less parasite)
what is an extended phenotype?
where parasite does not have a phenotype but can extend the phenotype of its host by influencing its behaviour
e.g. when hairworms causes expression of proteins that cause phototaxis => lead insects to move towards light reflected in water
How does mutualism drive coadaptation?
species evolved interactions in which both partners benefit
