BIO120H1 Lecture Notes - Lecture 9: Allopatric Speciation, Ecological Speciation, Reproductive Isolation
36
BIO120H1 Full Course Notes
Verified Note
36 documents
Document Summary
Flightlesness of birds on islands is a not disadvantage on islands because the loss of wings increases diving availability. To understand species, you have to understand the origin of reproductive isolating factors. No universal species concept, it varies among groups of organisms. E. g. interbreeding doesn"t apply to asexual species. Taxonomy: use morphology (distinct morphological differences) in species where you can"t conduct reproduction experiments. Biological definition is based on crossability/inter-fertility among individuals: ernst mayr at harvard came up with this concept, group of interbreeding natural populations that are reproductively isolated from other such groups, dobzhansky first came up with the idea. There"s a barrier to gene flow and they diverge. When they come together, their genes have changed enough that they can"t mate anymore. Very common and geographic barrier is required. Biological populations of the same species become isolated from one another to the point. New species evolve from single ancestral species while in the same geographic region.
