Islands And Speciation: Richard Dawkins’s The Greatest Show On Earth.., His Book On Evidence For Evolution

I’m near the 1/2 way mark of Richard Dawkins’s The Greatest Show On Earth..., his terrific book on the evidence for evolution.

As a long past English major with not much science in my soul—though I love, revere, bow down to, the idea of science—I didn’t follow a lot of the stuff on the molecular ways of cells. But I’m following a fair bit of the other things Dawkins discusses.

I just read, got and liked Dawkins’s notion of understanding the idea of islands from the standpoint of animal, or indeed from any life or plant form surrounded on all sides by what is uninhabitable or threatening, the way land surrounding water would make the water an island to a fish, or even how deep water surrounding shallow water would make the shallows an island to shallows inhabiting fish like coral fish, or how surrounding desert makes an island of an oasis. 

The point of this is how innumerable disruptions of the island environments so understood over billions of years led to innumerable instances of speciation since species are differentiated by their inability to breed and, so, genes favouring survival in new environments lead to unique evolutionary progression away from mitigation through breeding by the former split off species. 

If I have that generally and more or less right.

I had never thought of “Island disruption” as the key to speciation.