interbreed• Did they trade, make war, interbreed?• Fish of different shape are already reluctant to interbreed.• There, he said, many animals interbred and createdmonsters.• Although they can be prevailed upon to interbreed in captivity, they never do so in the wild.• Of the few species that do have the opportunity to interbreed, none do so frequently.• Theoretically, as we have seen, a species is a form which can not interbreed successfully with any other.• Graymoths still could interbreed with black moths, proving that they belonged to the same species.• Varieties and eventually species would be formed despite any tendency for interbreeding with the main body of the population in the centre.