Isolation and Speciation Flashcards
What is speciation
Process by which new species arise after a population becomes separated and cannot interbreed
What is allelic frequency
The number of times an allele occurs within the gene pool
In terms of allelic frequency, what is evolution by natural selection?
A change in the allelic frequencies within a population.
What is allopatric speciation?
Where speciation occurs due to the species becoming geographically separated
What is sympatric speciation?
Where speciation occurs even if the species are found within the same geographical area
Process of allopathic speciation forming
Reproductive isolation occurs or no gene flow between the geographically different organisms
These experience different selection pressures
Variation then occurs due to mutation in the different populations
Advantageous alleles passed on, cause a change in allele frequency
Eventually species are too genetically different to interbreed
Process of sympathetic speciation occurring
Occurs in the same habitat/ environment
Mutation occurs
Gene flow is separate
Different alleys passed on , causes a change in allele frequency
This results in disruptive selection
Eventually species can no longer interbreed
What is genetic drift?
Variation in allele frequencies in a population due to chance
Why does genetic drift only occur in small populations?
Small populations have a smaller variety of alleles
