2019 and 2020 books are in the
Odds and Ends
Be careful what you say
15 7, 5:41pm
No, no, no. Please, have even slightest understanding of biology before making such ridiculous statements. And kindly have some respect for people whose life's work is to study the phenomenon of evolution. Absurd repetition of over 60-year old debunked theories does not help your case in the slightest. You are an example of the social phenomenon trying to trump over actual scientific research with made up "facts".
Species evolve through subspecies, not "races". Human phenotypes are not even close to qualifying as different subspecies; the only thing they reflect is slight variations in external appearance, which is environmental adaptation at its simplest. It takes only a handful of generations for a species of butterfly to transfer from primarily black to primarily white colouration and back, depending on the most viable landing surfaces in their living environment. It doesn't take much longer than that for humans; light skin tone is less than 10,000 years old phenomenon, a far too short time in human generations to cause separation of subspecies, let alone species. Like the colour of butterfly wings, the colour of human skin tells nothing of genetic distinction in and of itself.
Neanderthals were a close species/subspecies to Homo Sapiens that was absorbed by our species with absolutely no adverse effect, so I have no clue about what "unpleasant" consequences of genetic mixing you are talking about. A wider genepool is always more viable for evolution than shallower one, and subsequently exchange of genes between more distant populations is always a positive factor from evolutionary standpoint.