18.5 isolation and speciation Flashcards
population definition
group of individuals of one species that occupy the same habitat that can interbreed
alleles definition
different forms of the same gene
allelic frequency definition
number of times an allele occurs within the gene pool
gene pool definition
total number of all the alleles of all the genes of all the individuals within a particular population at a given time
speciation definition
evolution of new species from existing ones
allopatric speciation definition
geographically isolated leading to the formation of a new species from existing ones
sympatric speciation definition
reproductively isolated leading to the formation of a new species
how new species are formed by allopatric speciation
- Geographic(al) isolation;
- Separate gene pools between populations
- Variation due to mutation;
- Different selection pressures due to their different environments
- selected organisms survive and reproduce
- Leads to increase in allele frequency.
how new species are formed by sympatric speciation
- reproductive isolation
- separate gene pools between populations
- variation due to mutation
- different selection pressures due to their different feeding times (for example)
- selected organisms survive and reproduce
- leads to increase in allele frequency
what is adaptive radiation?
population becoming adapted to its local environment
species definition
group of individuals that can reproduce to produce fertile offspring
