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Plant Sciences, Zoology & Evolution / Re: Can dogs breed with foxes?
« on: 14/05/2013 07:31:32 »
All gene-centered theories of reproductive barriers have serious flaws. If the barrier is supposed to come into place by gradual accumulation of differences, then it should be possible to predict reproductive barriers based on genetic difference data alone. It is not. Experiments with irradiated fruit flies shows that some became sterile directly while others remained fertile up to 20% mutated DNA. Lizards from different islands in the Martinique island chain interbreed and produce fertile offspring... and genetically they are almost as different as a human from a chimp.
The gradual accumulation theory also predicts that big populations with little genetic drift should accumulate individual variation until they became sterile and died out, and yet there is not one scrap of empirical evidence for large populations spontaneously becoming sterile and dying out.
The theory of single key mutations, on the other hand, has the problem of how the first individual with the key mutation should find a mate.
So all theories of genes determining reproductive species barriers are fatally flawed. Maybe mutations are not random...
The gradual accumulation theory also predicts that big populations with little genetic drift should accumulate individual variation until they became sterile and died out, and yet there is not one scrap of empirical evidence for large populations spontaneously becoming sterile and dying out.
The theory of single key mutations, on the other hand, has the problem of how the first individual with the key mutation should find a mate.
So all theories of genes determining reproductive species barriers are fatally flawed. Maybe mutations are not random...