/sci/ - Science & Math

Look
You become a different species when interbreeding stops being possible. Sometimes you see species live in different niches across the globe separated by the size of the world, with different adaptions, but you interbreed. Or you see interbreeding resulting in non viable offspring, or sterile offspring.

The problem when applying this to humans is that the core of the human experience(smart endurance hunters) means the ability to adapt to different niches and avoid adaptive evolutionary pressure. Tool use means you can just suffer a decline in numbers instead of a mass die off that would force evolutionary adaption.
Which means the most significant adaptions observed in humans is skin color and small changes in the human guts to adapt to diets. Alongside tribes living in very elevated environment such as Sherpas having small changes to their blood chemistry.

This is further compounded by the fact Eugenics turned into a nothingburger, and that its politically unpopular.
Haplogroups is just Eugenics 2.0 at this point, but it has actual data used for the flawed arguments it presents. Haplogroups are the closest you get to 'races of humans', but its still insignificant to what happens in the animal kingdom when there are mass die offs.