Constraints On Adaptation Flashcards
Salt marshes are an example of ..
An environment that organisms failed to adapt to
What 2 things are good for adaptation?
Behavioural and genetic variance (tropical sp don’t always have genetic variance)
G-matrix stands for?
Genetic variance-covariance Matrix
What can be used to predict how populations behave in future and model simulations of evolution?
G-matrix
What constrains adaptations?
G-matrix
Some adaptations can be caused by a single base pair mutation..will genetic variance occur?
Possibly
Can mutations save a species?
No, some mutations increase genetic variance but decrease fitness
Genetic variance + environmental variance =
Phenotypic variance
Define pleiotropy
Same gene influences different characters
Define linkage disequilibrium
No random association among genes that independently affect each character
Genetic correlations:
Linkage disequilibrium and pleiotropy
Valleys and peaks are associated with what?
Adaptive landscape
Selection can push a trait into a valley
False, can only push up the nearest peak
Which is slower: pleiotropy or linkage disequilibrium?
Pleiotropy
Independent genetic variation in 2+ characters results in selection favouring a combination..what is this?
Correlated selection
Define reaction norm
1 gene can create a range of morphs
Environmental conditions determine the phenotype response, can selection act on a morph?
Different morphs are favoured in different environments so a morph must persist long enough to allow selection to act or it hides from selection
If a feature is strongly correlated with another trait that is being selected for, what happens?
Will evolve in the opposite direction of selection
If a trait evolved by directional selection =
Diverged faster than expects neutral rate
If a trait diverged slower than expected neutral rate =
Evolved by stabilising selection or other characteristics were affected by the same gene
Inhibited gene flow from populations adapted to a different environment is a definition of
Constraints
Genotype produces different phenotypes dependent on environmental conditions
Phenotypic plasticity
Phenotypic plasticity results in
Increase survival in altered environment