I watched the video and that's what the fictional presenter says. I don't think it really makes sense though, but maybe you can get passed that because the spec

I watched the video and that's what the fictional presenter says. I don't think it really makes sense though, but maybe you can get passed that because the species coming into existence at all is so contrived and unlikely? The vampires appeared to have less of a gene pool and more of a gene cleanroom. Knife edge stuff there.