CO-EVOLUTION

Define coevolution

+2 species: exert selective pressures on each other, and evolve in response to each other

When does co-evo occur?

When there’s a close eco relationship (specialists > generalists)

Coadaptation

Reciprocal adaptations of 2 species; could refer to species, adaptations possessed by idv, gtypes, etc.

Figs are not fruit but rather

specialized inflorescences

Cospeciation

like in fig and pollinator relationship, both indicate a very tight eco relationship

Figs coadapted to both pollinators and parasites so

figs must balance their own reproductive success against the need to maintain pollinator specificity AND reduce impact of parasites

Pocket gophers are parasitized by

lice

Arms race

coevolving species have to constantly “improve” to meet each new adaptation w a “better” adaption of their own

Escalation

coadaptation become inc powerful, yet species are not any better adapted because the selective landscape is constantly changing

Newts producing a highly toxin that its predator snake is resistant to it is an example of

an Arms race in a pred-prey interaction

Difficult to infer coadaptation from fossils because

we can’t observe interactions, but we can use characteristics that reflect pred-prey interactions

Evolution is NOT

progressive

Why are there so many species of beetles?

Plant feeding beetle are monophyletic group, but specialized feeding on angiosperm has evolved multiple times w/in phytophagous beetles

Abiotic interxns

interxns w/ temp, light, nutrients, humidity, etc

Biotic interxns

interxns w/ other organisms

Coevolution occurs ONLY as a direct result of

biotic interactions