BIO120H1 Lecture Notes - Lecture 20: Ecological Speciation, Hybrid Zone, Aquilegia
36
BIO120H1 Full Course Notes
Verified Note
36 documents
Document Summary
A group f interbreeding natural populations that are reproductively isolated from other such groups. Allopatric speciation a single population gets subdivided because of geographical barrier (due to mountain range, waters, etc. ). It impedes and limits gene flow between the two populations; they will diverge, and alternate alleles get fixed in either population. Each becomes so sufficiently different that, when they come back into contact (secondary contact), they cannot breed. Sympatric speciation sympatry means growing together (allopatry means growing apart). The population diverges and becomes a new species. Occurs and is common in plants, but is still controversial for many animal species. Stages when ri can occur: finding a compatible mate (ex. same habitat?) Mating and fertilization (ex. may mate, but f1 zygote is maladapted or has bad genes) Speciation involves the evolution of reproductive isolation between populations. Pre-mating: prevents zygote formation, geographical, ecological, temporal, behavioural, mechanical, prevention of gamete fusion. Premating isolation in apple maggot flies: habitat and temporal isolation.
