(Symbol image). A simple pair of glasses today replaces, in seconds, what natural selection once took millennia to resolve. Everyday items like these are at the center of a hypothesis suggesting that human evolution is shifting its primary mechanism. Glasses, vaccines, and cesarean sections are viewed not as mere medical footnotes, but as evidence of a deep restructuring of adaptation. The implications for the future of humanity are the focus of a new theoretical work.
(Photo: © Forschung und Wissen)
Glasses correct in minutes what natural selection couldn’t solve in thousands of years. Based on this observation, two researchers from the University of Maine propose a far-reaching thesis. It’s no longer just genetics but the transfer of knowledge that provides faster answers to disease, environmental changes, and shortages. In the journal BioScience, they describe a transformation whose endpoint even evolutionary biologists have previously considered unlikely.
Evolution in biology refers to the change of inherited traits over generations. The classic pathway operates through the genome. Mutations create variations that natural selection filters, and since a human generation averages about 25 to 30 years, this process takes centuries to millennia to establish beneficial variants in a population. However, there exists a second channel of inheritance, described by the theory of dual inheritance for decades. Humans transmit behaviors, tools, and rules through imitation, teaching, writing, and technology without altering a single base pair. This cultural inheritance works horizontally rather than exclusively vertically, skipping generations and can spread within months throughout a population. While both channels operate parallelly, their speeds differ by several orders of magnitude. This difference is moving to the forefront of debates on human evolution.
Timothy Waring, an associate professor of economics and sustainability, and ecologist Zachary Wood have formalized this speed discrepancy into a hypothesis. They discuss an evolutionary transition in inheritance and individuality, placing it alongside major upheavals in life’s history, such as the shift from single-celled to multi-cellular organisms or from solitary insects to highly cooperative states. Such transitions change not only how quickly life adapts but also what is considered an evolutionary unit. For a long time, the idea that a comparable process could occur in humans was deemed speculative, as cultural evolution appeared too nebulous for robust models. The interdependence of selection pressure and cultural technology illustrates that humans may lose certain body parts in the long term once medicine, nutrition, and technology replace their original benefits.
Why Culture Outpaces Genetic Adaptation
The key term in this work is preemption. This means that a cultural solution can address a problem before genetic adaptation has even begun to take effect. Nearsightedness would have been a measurable disadvantage in hunter-gatherer conditions, but it’s now neutralized by glasses, contact lenses, or laser surgery. Cesarean sections make possible births that would have been fatal in the past, vaccines decouple survival from random immune variants, and reproductive medicine enables offspring where biology alone reaches its limits. In an analysis on cultural inheritance in humans published by Oxford University Press, the authors argue that such effects do not just affect isolated cases but shape the entire adaptation process. The selective pressure on many genetic variants may not drop to zero but loses significant effectiveness.
From Individual to Group
The second part of the hypothesis is the more uncomfortable one. Culture is not private property; it’s a shared phenomenon. Consequently, cultural solutions almost always emerge at the group level. A pair of glasses necessitates an optics industry; a vaccine requires a research system, a cold chain, and an approval authority; a cesarean section demands a clinic with training, electricity, and hygiene standards. Authors suggest that advancements in life expectancy and survival are more reliably attributed to institutions than to individual capabilities or genetics. Those who live long today owe it less to their personal biology than to the country they inhabit. This suggests a shift in what is considered the unit of adaptation: from the individual body to the organized group. In this view, human societies increasingly resemble a superorganism, comparable to the division of labor in social insect colonies, only connected through shared knowledge rather than degrees of kinship. A look at genetic deep history highlights the contrast, as modern humans derive from two ancient founder populations whose mixing took hundreds of thousands of years.
What the Hypothesis Leaves Open
Waring and Wood emphasize that their proposal is a theory rather than an empirical proof. Their primary contribution lies in making the transition measurable. They suggest quantitative metrics to assess the proportion of traits and fitness differences attributable to genetic versus cultural causes, and they are developing mathematical and computational models along with long-term data collection. In the accompanying announcement from the University of Maine about cultural evolution, the researchers also caution against equating cultural change with progress. The same cooperative structures that tap into resources and protect humans can also generate competition, overuse, and climate risks. Whether the transition has been completed remains open. The extent to which biological and cultural development intertwine is already evident in early history when the human brain attained its modern form around 1.7 million years ago in Africa.
BioScience, Cultural inheritance is driving a transition in human evolution; doi:10.1093/biosci/biaf094
