Speciation

2 Allopatric Speciation

Allopatric speciation (geographic speciation)- from the ancient Greek allos, "other" + Greek patris, "fatherland") is speciation that occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with gene flow.

New Zealand splitting from Gondwanaland isolated many populations and led to species of plants and animals that evolved in the absence of many species of mammals. In fact NZ has just four species of bats which are the only land mammals to exist prior to the arrival of humans.

Video: Ghosts of gondwana

Animation showing the split of NZ from Gondwanaland

Website article on evolution of NZ parrots

Video showing the movement of plates and the changing shape of NZ over last 100million years video

3 Sympatric speciation

Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region.

Sympatric speciation is due to:

1. Niche differentiation (VIDEO)

2. Non-disjuncture during meiosis (click on "GO TO ANIMATION") or this is another good animation

Watch this animation to see what should happen during meiosis and how new species are formed via sympatric speciation

This animation goes into the nuts and bolts of how polyploids can lead to new species