There’s no real scientific basis of there being such a thing as a “race”. There’s many more sub-phenotypes of homo sapien than there are “races”. Hell, in Africa alone there are something like 14 edit: 13 (sorry, had to fact check myself there) major, distinct genetic groups [1]. Many of the major pacific islands also have distinct genetic lineage; so much so that they can be reliably grouped into which island they originated from. “Race” is far too broad of a term and wholly unscientific; it should be broken down in a far more granular fashion. (in my opinion the benefit of this being that it’s unlikely to be worth it to racists to remember all the groups they’re trying to hate)
The comment was a poke at the people (like yourself) who always jump to the conclusion you’ve jumped to; as well as the scientists who constantly walk on egg shells to avoid any topic like intelligence, because they will be roasted alive by hypersensitive people who are just looking for someone to attack. So their findings, and their reports are chastised in order to fit that particular nuance of our society.
Additionally, the reason I think we should stop shying away from distinctly organizing these genetic groups, is because in lots of cases of medical research, these genetic lineages aren’t being taken into account. Many drugs work differently on West-European patients than they do on East-Asian patients; or have different efficacy. These things need to be taken into account if we’re ever going to create the right medicine for the right people.
It’s worth noting that distinct lineages only really happen where there is reproductive isolation and that especially in the modern world no one has a “pure” lineage. Instead you have genetic composition that might have a larger influence from one ancestral population over an other.
The modern world with intercontinental travel is a relatively new thing. Even with that, many people don’t travel far: https://www.forbes.com/sites/lealane/2019/05/02/percentage-of-americans-who-never-traveled-beyond-the-state-where-they-were-born-a-surprise/
There’s plenty of reproductive isolation; especially when we’re talking about timelines on the orders of thousands of years here. It’s a myth that humans are some sort of ‘melting pot’, as we really haven’t been until this latest generation; due to ease of access to travel, better living conditions, access to birth control, and evolving social acceptance.
Doesn’t matter if not everyone is traveling far to reproduce, it only takes a few people to introduce a blob of diversity into an otherwise isolated population and suddenly all their ancestors become contributors to that areas gene pool. Without repeated introductions it won’t form a large part but it will form part. For example most people have direct neanderthal and denisovian ancestors and it’s not estimated that pairing between modern humans and those populations were all that regular an event and yet their genes are everywhere.