(1) They do have the DNA... That's actually how this discovery came about, and the reason for all the progress in this field over the last few years. Svante Pää

(1) They do have the DNA... That's actually how this discovery came about, and the reason for all the progress in this field over the last few years. Svante Pääbo at the Max Planck Institute and his team invented a method to extract DNA from ancient bone fragments a few years back. (@) The term "species" doesn't really have a definition in biology. You seem to be suggesting that producing offspring defines two individuals as belonging to the same species. That's not a workable definition because most life on earth doesn't breed at all. It's also not the correct, obsolete definition, which had always been "producing offspring that is itself fertile". Otherwise, tiger and lion are one species (producing infertile liger when they mate).