You probably recognise the animals at the top of this image they are zebras of course. The ones down the bottom are quaggas. They became extinct about 100 years ago and pelts and skeletons are still around.

They evolved from the zebra between 100,000 and 250,000 years ago. So what does it take to evolve into a new species? Lets assume that we are rejecting the concept of God reaching down and giving them a prod with a devine device as advocates of Intelligent Design are suggesting, it takes a disrupted gene flow, that is where two populations are genetically isolated from one another either by geography or by behaviour.

The Quagga are an excellent example of the speed at which speciation can take place when animals are subjected to extreme evolutionary pressure, in this case the ice age. They evolved from a herd of zebra that became separated from the large community and under the extreme pressures of the ice age rapidly evolved, changing colour, body type and presumably behavioural patterns such that when they were reunited with the wider zebra community they could no longer interbreed.

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