The Empirical Referee Between 'Evolution Stopped' and 'Skin Deep'

2026-07-20 · AI-generated insight

Derbyshire's taxonomy of human nature turns on a single empirical claim, and the ancient DNA paper delivers a verdict on it. His "Culturist" holds that evolutionary processes "ceased in the early history of the species," leaving a human nature uniform and infinitely plastic. Gould's argument leans on an adjacent premise: because races are recent, genetic differences must be minor, quite literally "skin deep"—concentrated in visible traits like pigmentation while the deeper architecture stays uniform.

Both claims share a structure: recent time plus superficial reach. And both are precisely what the West Eurasia study measures against. If evolution had stalled, we would expect the last ten millennia to look like the long span before it, when hard sweeps were rare. Instead the authors find hundreds of alleles under strong directional selection in exactly the recent window Culturism declares closed. The Culturist's foundational timeline is simply false as a matter of allele frequencies.

Gould's inference is the more interesting casualty, because it's subtler. He is right that races are recent; his error is assuming recency implies superficiality. The study documents selection not just on pigmentation but on combinations of alleles that today predict body fat, schizophrenia risk, and cognitive performance—one-standard-deviation shifts on the scale of modern variation. Ten thousand years turns out to be long enough for directional selection to reach well past the skin. "Skin deep" was an inference from an assumed rate of change, and the rate was underestimated.

Notice, though, that the paper also disciplines the triumphalist reading. Its authors flag that these effects were "measured in industrialized societies" and that it "remains unclear how these relate to phenotypes that were adaptive in the past." That caveat is where Derbyshire's Biologian should show restraint: demonstrating that selection occurred is not demonstrating what it optimized for. The data dissolves the Culturist's timeline and Gould's superficiality thesis without licensing confident stories about what any given allele was selected to do. The honest position that survives is narrower than any of the three tidy theories—evolution kept running, reached deep, and left us guessing about its purposes.

Woven from these notes

Ancient DNA has transformed our understanding of population history, but its potential to reveal as much about human evolutionary biology has not been realized because of limited sample sizes and the difficulty of distinguishing sustained rises in allele frequency increasing fitness—directional selection—from shifts due to migrations, population structure, or non-adaptive purifying or stabilizing selection. Here we present a method for detecting directional selection in ancient DNA time-series data that tests for consistent trends in allele frequency change over time, and apply it to 15,836 West Eurasians (10,016 with new data). Previous work has shown that classic hard sweeps driving advantageous mutations to fixation have been rare over the broad span of human evolution8,9. By contrast, in the past ten millennia, we find that many hundreds of alleles have been affected by strong directional selection. We also document one-standard-deviation changes on the scale of modern variation in combinations of alleles that today predict complex traits. This includes decreases in predicted body fat and schizophrenia, and increases in measures of cognitive performance. These effects were measured in industrialized societies, and it remains unclear how these relate to phenotypes that were adaptive in the past. We estimate selection coefficients at 9.7 million variants, enabling study of how Darwinian forces couple to allelic effects and shape the genetic architecture of complex traits.

Ancient DNA reveals pervasive directional selection across West Eurasia 2026-07-20

There are three theories of human nature enjoying widespread support at present. For convenience, I’ll tag each one of them with a single adjective. Religious. Our species Homo sapiens is the special creation of God, either as a one-off miracle or by God-guided evolution. Human nature is a mix of attributes, some natural ones arising from plain biology, some supernatural ones inserted by God. We are the Chosen Species. The God-given attributes are unique to our species. They are the same in all human populations, forming the foundation of our essential equality. Their existence is independent of our biological nature, even to the degree that they can continue to exist after our deaths. Being nonbiological, they don’t evolve, even if other features of the living world do, so that our evolution, if it ever took place, ended (except perhaps for some incidental biological features) when God decreed we have these supernatural attributes. These God-given attributes include the moral sense, which accesses transcendent truths—i.e., truths that do not dwell in the world of matter. God rules! Cultural. Our species arose, like all other species, from the ordinary processes of evolution. However, these processes ceased in the early history of the species, leaving us with a human nature uniform across all populations and unchanging over time, forming the foundation of our essential equality. This human nature has very little innate structure and is extremely plastic. By placing it in a suitable environment, or applying suitable pressures, the mind (and therefore the behavior, which issues from the mind) can be shaped in any way at all. “Human nature” does not really exist independent of the environment an individual happens to be in, especially that part of the environment made up of other human beings—“the culture.” Moral standards are arbitrary, and are taken in by the individual from the culture. Culture rules! Biological. Our species arose, like all other species, from the ordinary processes of evolution, which have continued to the present day. Human nature is a collection of characteristics all susceptible to biological explanation. Some characteristics of a person’s nature can be shaped to some degree by “cultural” (i.e., social or environmental) forces; some cannot. Human beings are a part of the living world, and nothing more. Our equality consists in being members of a single species; though our species, like any other with very wide distribution, exhibits regional differences. The characteristics of an individual human being are templated in his genome. They may be somewhat modified by womb events or life experiences; or they may need to be “instantiated” by postpartum environment. (An individual’s genome may, for example, predispose him to be eloquent or tongue-tied when using language; but which language he uses will depend on his childhood environment.) The repertoire of human behaviors, and of ideas, including moral ideas, about behavior, are innate, the result of evolutionary processes acting on our social lives across many generations. Biology rules! For convenience in what follows, I’ll label adherents of these three views with the more or less made-up words “Religionists,” “Culturists,” and “Biologians.” Each point of view has a history. Religionism emerges from core features of human thinking, as described by cognitive scientists like Pascal Boyer (Religion Explained, 2001), Scott Atran (In Gods We Trust, 2002), and Bruce Hood (Supersense, 2009). Culturism has roots in the tabula rasa (“blank slate”) theories of Aristotle and Locke. It was put into its modern form by German anthropologist Adolf Bastian (1826–1905). Bastian coined the phrase “the psychic unity of mankind.” His student Franz Boas brought these ideas to the United States, becoming the most influential American anthropologist of the early twentieth century. Biologism is just ordinary scientific method applied to humanity.

— John Derbyshite We Are Doomed 2026-07-20

obvious: As long as most scientists accepted the ancient division of races, they expected important genetic differences. But the recent origin of races… squares well with the minor genetic differences now measured. Human groups do vary strikingly in a few highly visible characters (skin color, hair form)—and this may fool us into thinking that overall differences must be great. But we now know that our usual metaphor of superficiality—skin deep—is literally

— Gould 2026-07-20