This mantra — “White people are no more closely related to one another, genetically, than we are to black people” — is one of the most common urban legends of the 21st Century even though it’s obviously stupid. (It seems like I used to know where this myth originated, but I’ve forgotten.)
If you have any sense of how genetics are related to genealogy, then it’s clearly not true on average.
As the authors used more and more markers to compare the three major racial groups (Europeans, East Asians, and sub-Saharan Africans), the less stringent clustering measurements rapidly fell to a 0% overlap, as expected from previous studies. What about the more stringent measurement “w”, which looks at comparisons between individuals, and does not consider group data? It is useful at this point to quote the authors about this fundamentally important finding:
This implies that, when enough loci are considered, individuals from these population groups will always be genetically more similar to members of their own group.
With respect to the question of whether individual members of one group may be genetically more similar to members of another group, they write:
However, if genetic similarity is measured over many thousands of loci, the answer becomes ‘never’ when individuals are sampled from geographically separated populations.