What is co evolution?
reciprocal evolution.
changes in one species cause changes in second
occurs with co adapation
What is character displacement in coadaption?
when a characters increased in the presence of co species.
-arms race.
What are the main reasons for co adaptation?
competition
predation
parasitism
mutualism/symbiosis
Give an example of coadaptation due to competition
Stickleback competition
Sticklebacks invaded lakes created by ice retreat, some lakes now have one species some have 2.
The lakes with 2 species have diverged into Benthic and Limnetic forms with distinct diets and niche partitioning.
Give an example of coadaptation due to predation
Shell thickness in molluscs over geological time
- arms race between competitors and predators
- red queen metaphore for coevolution dynamics
Give an example of coadaptation due to parasitism
Brood parastism by cuckoos
-mimic egg colour of host foster parents
-host counter adaptation and distinguish egg
arms race
Give three examples of parasites that cause behavioural changes in host
Juvenile hair worm -insect parasite -adult needs water to mate -infected insect jumps into water and emerges vis phototaxis protein (moves towards light) Cordyceps fungui -parasite of insects and spiders -infected ant, climbs high -fungus sporacucles and wind disperses. Toxoplasma protozoan -warm blooded animals -cat main host -makes rodents less fearful of cats - seeks out cat urine marked areas, via increased dopamine levels in brain.
What is mullerian mimicary?
2 or more poisoness species that share 1 or more common predators have come to mimic each others warning signals.
What is Batesian mimicary?
harmless species evolved to mimic/innitiate warning signs of poison harmful against common predators
What is commensalism?
give an example
one organism benefits from the other without affecting it
- pollination by sexual deception in orchids.
- looks like bee
- tries to fuck
- picks up pollen
- no bee reward
What are two examples of plant mutualists?
ant/acacia mutualism. - ants produce alarm pheromones that deter herbivores, ants get home.
mycorrhiza
