Microevolution Flashcards
What can cause a change of allele frequency in a population over generations?
Mutation, selection, gene flow or genetic drift
What causes adaptive divergence?
Adaptation of different populations to different environments
Explain adaptive divergence
It involves the evolution of phenotypic traits that improve fitness for individuals in their home environments relative to individuals from other environments
Name six ways of how to infer adaptive divergence
1) Trait-environment correlations
2) Reciprocal transplant experiments
3) Phenotypic manipulations
4) Divergent selection
5) Experimental Evolution in Nature
6) Comparisons to neural expectations
Define adaptive radiation
The evolution of ecological diversity within a rapidly multiplying lineage (Schluter, 2000)
Phenotypic differentiation between populations is caused by what?
By differences in the environments they inhabit and the resources they consume
Explain gene flow
It is the exchange of genes among populations because of successful reproduction by migrants
Lis four effects of gene flow on adaptive divergence and speciation
1) Keeps populations from reaching local adaptive peaks, which can decrease mean population fitness and perhaps limit species geographical ranges
2) May prevent or delay the evolution of reproductive isolation
3) May depress the mean fitness of populations by introducing maladaptive genes
4) May facilitate shifts between peaks on an adaptive landscape, thereby contributing to adaptive evolution
Define ecological speciation
Occurs when the adaptation of populations to different environments drives the evolution of barriers among them
List some reproductive barriers that can evolve as a result of adaptive divergence
1) Habitat preference
2) Selection against migrants
3) Temporal isolation
4) Mate choice
