The Host's return (The Ancestor's Tale)
In the final chapter of The Ancestor's Tale Richard discusses the idea of re-running evolution. If memory serves the argument was that it would produce similar but not identical results.
I was reading an article on blind cave fish and I thought that here was an actual living example of evolution being run from the same starting point multiple times.
Essentially the researchers have determined that the various populations of blind cave fish are more closely related to the surface population than they are to each other. This is despite the cave populations looking the same - all having lost both pigment and eyes.
I realise that it's a short journey from coloured, sighted fish to unpigmented blind fish but thought it interesting anyway.
Another point of interest about this study is that the underground populations remain distinct despite a regular inflow of genes from surface fish. The selection pressure must be very strongly against having eyes and producing pigment.