Forum debate: Human races vs. genetic similarities

The 0.01% of DNA that separates a hut from the Moon

In the thread, several participants argue that human races do not exist. The repeated argument is that all humans share more than 99.9% of their DNA, and genetic variability within what we call races is greater than between them. Other users counter that applying this same criterion to a coyote and a chihuahua, which are distinct species, or noting that we share 99.4% with chimpanzees, highlights the limitations of this argument. The discussion, far from being resolved, gets stuck on the definition of terms.

What population genetics says and what it misses

The debate asserts that visible differences—pigmentation, hair, facial antiestéticatures—are local adaptations to specific environments and do not reflect deep distinctions between groups. Human variation would be a continuum, not a mosaic of sealed compartments.

Other participants point out that this same criterion, applied with taxonomic rigor to primates, crows, or tigers, does admit subspecies and lineages. Some highlight the asymmetry: a strict biological criterion would be required to deny human races, while relaxing that criterion for everything else. The classic objection—the Lewontin fallacy, debunked by Edwards—points out that differences within populations and between populations are of different natures, not comparable magnitudes. In other words, the shared 99.9% would not cancel out the remaining 0.1%; it would make it more relevant, not less.

The 0.01% that decides if you digest milk or reach the Moon

Here the ground becomes slippery. If natural selection has shaped lactose or gluten tolerance in specific populations, the thread asks why it would stop at cognitive or behavioral traits. Those defending this thesis argue that denying it is a political decision, not a scientific one, and that those who question it face academic ostracism. Those who reject it respond that the heritability of complex traits is low, that environment weighs heavily, and extrapolating group differences to individuals is a textbook statistical error.

The discussion gets tangled with epigenetics: genes activate or deactivate depending on what you do with your life. This complicates any determinism. But it does not eliminate it.

Neanderthals, bison, and the boundary of the species

A technical detail mentioned in the thread: species classification predates genetics and is not based on it. Neanderthals were distinguished by notable physiognomic traits, and it was a surprise to discover they could reproduce with sapiens. Today there are currents asking to reclassify them as subspecies or races. Something similar happens with the American and European bison: they can interbreed, but under natural conditions they would not. The boundary between species, subspecies, and race is blurrier than classical taxonomy suggests.

Vitamin D, Eskimo diet, and the cost of ignoring adaptation

The most cited case is pigmentation and vitamin D. In latitudes with little solar radiation, very pigmented skin hinders the synthesis of this vitamin. Hence the talk of evolutionary advantage for light skin in the north. Those taking the argument to the extreme ask: if we are genetically identical, why don't we all adopt an Eskimo diet? The obvious answer is that adaptation is not just cultural.

The underlying problem: who defines the words

The discussion keeps deriving to the same point: there is no clear criterion to draw genetic boundaries between races. And from there, the jump is made that races do not exist. Those questioning that jump recall that the word race predates genetics and was used to group populations by phenotypic traits. Denying the category for political convenience, they argue, is playing with language. The opposing response: if the concept lacks a solid biological basis, using it only serves to justify hierarchies.

And at the bottom of it all, the uncomfortable question: if races do not exist, do racists exist? Can you discriminate based on something that does not exist?

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Science will continue refining the map. What is unclear is whether anyone is willing to accept the result, whatever it may be.