The tone of the article was a bit strange, as was the way it kept referring to "ancient" genes and such. If they're genes in modern people (Melanesians), how a

The tone of the article was a bit strange, as was the way it kept referring to "ancient" genes and such. If they're genes in modern people (Melanesians), how are they any more ancient than any other genes that exist chiefly in one population subgroup? Isn't it becoming increasingly indefensible to talk about "our own" species (or "us") when we know that all these species interbred and that their genetic material lives on in modern humans, even "anatomically modern" humans?