Ah, so as this Independent article on the same subject makes clear, the idiot was the journalist, not the curator of the Zoological Society. It seems the theory was that the parthogenesis ability evolved in the normal fashion and the reproductive advantage was that a female who evolved this ability swam to / was washed up on an island alone, and was able to reproduce. The BBC journalist then utterly misunderstood the theory. Well, my confidence in the Zoological Society is restored, at least. The BBC need to send their reporter back to high school, though.