Coevolution Flashcards
What is coevolution?
A reciprocal process where a pair of species evolve in response to eachother.
What is an example of evolution without co-evolution?
Hermit crabs evolving to use mollusc shells as homes, but molluscs not evolving to be perfect crab homes.
What are mutualisms?
Positive relationships between different species in which the interaction increases the fitness of both species.
What is a mutualism example?
Fungus-growing ants produce antibiotics to kill bacteria that infect the fungi. The fungi are passed to offspring to seed new nests. This is beneficial for both species.
What is another mutualism example?
Ants protecting caterpillars and pupae from predators and parasites. The ants receive sugary nectar in return.
How is this mutualism example costly for both species?
It is observed that lab-reared larvae grow much bigger if they don’t secrete nectar for the ants, and ants are more vulnerable to predators when protecting the larvae.
What is a problem with mutualistic relationships?
There may be recurrent selection for mutualists to cheat.
What was a test of response to cheaters?
The relationship between a soybean legume and a rhizobial bacterium showed that if rhizobium was prevented from fixing N2 the plant responded by reducing the oxygen to the rhizobium to stifle its growth.
What is antagonistic coevulution?
When two species may evolve to escape or withstand the negative effects of eachother within a predator-prey or parasite-host relationship.
How can an evolutionary arms race be formed in predator-prey relationships?
If a single predator species feeds on a single prey species, selection favours traits in prey that help evade predation which intensifies the selection on predators for traits that increase chances of prey detection.
What is Red-Queen dynamics?
The idea that species need to keep evolving to keep up with their environment and competitors.
How can an evolutionary arms raced be formed in a host-parasite relationship?
The parasites would evolve to specialise on the hosts, but the hosts are evolving to escape the parasites. This drives reciprocal adaptations.
Why does coevolution result in rapid changes?
The selective agent itself is evolving so there is a continous source of selection.
Coevolution can drive co-speciation so either species can only survive with the other.
This is just a fact that I don’t know how to form into a question. Read it.
