lecture 12- co-evolution Flashcards
what is co-evolution
when changes in one species cause adaptations in another which further changes the selective pressure on the first altering its evolution and so on
types of co-evolution
mutualisms - both benefit
an arms race
whats an arms race
adaptations by one species is detrimental to the fitness of the other
what is an aposematic animal
a species that uses bright colours to show its poisonous
what is needed for aposematism to work
for predators to remember the signals and to be adapted to learn the signal easily - mutualism
features that aid learning
conspicuousness
novel signal
repeated signal
consistent effect follows the signal
effect follows signal quickly
confirmed by other signals
costs of aposematism
baby predators haven’t learned the signals and they are often eaten so that they can learn the signal
what do aposematic animals do to reduce the chance of being eaten by baby prey
aggregate
how are signals shared across species
Mullerian mimicry
what is Mullerian mi
everything of the same colour is toxic but they share protection from predators as predators have learned that those colours are toxic
what type of evolution do Mullerian mimics experience
convergent
example of Mullerian mimics
monarch and viceroy butterflies
what is Batesian mimicry
when a non toxic animal mimics a toxic one
how are Batesian mimics harmful
they confuse the signal to the predators
who are Batesian mimics in arms races with
their model and their predators
how do mimics shift evolution
curves of protection - directional selection on mimics towards patterns like the model shifts the evolution of the model thus shifting evolution of mimic
are Mullerian mimics positively or negatively frequency-dependent
positively- do better the more of them there are - share costs of educating new predators
are Batesian mimics positively or negatively frequency-dependent
negatively - do better the fewer mimics there are - too many confuse the predators
why do polymorphisms exist
mimicks 2 different patterns for protection - disruptive selection
why don’t Mullerian mimics converge on 1 pattern
have more than 1 pattern as some patterns have huge Batesian loads
what are automimics
members of the same species that lack the defensive chemical
