Cultural evolution and the 300-times-faster headline

“Humans conquered the planet 300 times faster than genetic evolution can explain.” That number is not a measurement. It is a division.

Scientific American ran the sentence as a headline in March 2026, over work by Charles Perreault, an anthropologist at Arizona State University. Writing in the Proceedings of the National Academy of Sciences on March 17, he estimated that a mammal reaching the human geographic range by ordinary evolution would have needed about 88 million years. Homo sapiens has existed for roughly 300,000. Divide the first figure by the second and 300 falls out. Perreault’s own title claims less: cultural evolution, it says, accelerated human range expansion “by more than two orders of magnitude.” A hundredfold is a scientist’s number. Three hundredfold is a headline’s.

The demotion costs the argument nothing.

Perreault mapped the ranges of nearly 6,000 land mammals and modeled how a group’s range tracks three things: the age of the lineage, the number of species in it, and how widely body size varies within it. Humans sit far off that curve. One species holds about 51 million square miles; a typical wild mammal species holds about 64 square miles. Closing that gap biologically would take not only the 88 million years but more than 2,200 species and a body-mass range spanning four orders of magnitude. Humans did it while staying one species with one body plan.

They did it by acquiring a second inheritance system. Genes carry adaptations to children. Culture carries them to anyone watching. A parka pattern or a method for drying fish can cross a camp in a season, and no favorable mutation has to appear first. A child born into an Inuit community inherits little cold tolerance; she inherits the clothing, the hunting technique, and the people who know them.

What other mammals accomplish by branching, humans accomplish by teaching. Perreault finds the fit is tighter than the species comparison suggests: ethnolinguistic groups tend to occupy smaller and more specific territories than mammal species do. Culture adapts at a grain finer than speciation can reach.

Read literally, though, the headline still overreaches. Genetic adaptation did not stop when culture started. Lactase persistence appeared in herding populations, malaria resistance where the disease is endemic, altitude physiology in Tibet and the Andes, pigmentation under different sunlight. The two processes fed each other. Dairying created the pressure that made lactase persistence worth having.

The deeper trouble is the phrase “genetic evolution can explain,” which sets biology and culture against each other as rival accounts when one sits inside the other. Culture runs on large brains, language, a long childhood, and a compulsion to imitate; genetic evolution produced every one of them. “Conquered” overstates too: the species occupies the planet but does not run it.

Hold the estimate loosely. It is one model, in one paper, by one author, and it assumes range size in mammals tracks lineage age, species count, and body mass tightly enough to predict what humans would have required. Loosen that relationship and the 88 million years moves, and 300 with it.

What does not move is the direction. For most animals adaptation waits on who breeds. For humans it waits on who watches, listens, and remembers. Agriculture, writing, and machine learning run on the same mechanism, at speeds no genome can match, because knowledge outlives the people who find it.

Sources:

• Scientific American, “Humans Conquered the Planet 300 Times Faster Than Genetic Evolution Can Explain,” March 2026
• Charles Perreault, “Cultural evolution accelerated human range expansion by more than two orders of magnitude,” PNAS 123(11), e2523038123, March 17, 2026
• Arizona State University, “How humans took over the planet,” March 13, 2026