The mastery of fire is often presented as the great rupture in human evolution -- a cognitive and technical leap that radically separates us from other primates. But a new theory published in BioEssays in 2026 proposes an unprecedented perspective: it would be burns themselves that forged some of the most distinctive characteristics of human anatomy.

Campfire at night
Fire, mastered at least 500,000 years ago by hominins in AfricaAfricaThe cradle of humankind: the continent where the first hominins appeared, then Homo sapiens around 300,000 years ago, before the expansion to the rest of the world.→, radically transformed their way of life: food preparation, protection, nocturnal sociability. But it also exposed our ancestors to a permanent risk of burns.

The "Burn Selection Hypothesis," developed by Cuddihy's team, starts from a simple observation: unlike other primates, hominins spent much of their lives in proximity to intense heat sources. This chronic exposure would have exerted selective pressure on genes involved in wound healing and inflammatory response.[1]

Wound-Healing Genes Under Evolutionary Pressure

The researchers identified several genes linked to the treatment of skin burns that show signs of accelerated positive selection in the human lineage. In other words, these genes evolved faster in Homo sapiensHomo sapiensThe present-day human species, which emerged in Africa around 300,000 years ago, the only surviving human lineage after the extinction of Neanderthals and Denisovans.→ than in other primates -- an evolutionary signature observed only when a characteristic confers a significant survival advantage.

Homo rhodesiensis skull
Skull of Homo rhodesiensis (approximately 300,000 years old), an African homininHomininMember of the subtribe Hominina, comprising the human lineage (Homo, Australopithecus, Paranthropus…) but excluding orangutans and gibbons. The term progressively replaces "hominid" in its narrow sense.→ and probable ancestor of Homo sapiens. These populations almost certainly used fire regularly, exposing themselves to burns and associated risks.

Bare Skin: Thermoregulation or Protection Against Burns?

The evolution of human skin has already been linked to several adaptive advantages: reduction of body hair facilitating thermoregulation through sweating, sexual selection, infant care. Cuddihy's theory adds a new dimension: thermal protection against burns may represent another evolutionary driver of human skin specificity.

Human skin layers
Structure of human skin layers. Homo sapiens skin presents remarkable adaptations -- sweat glands, melanin, rapid healing -- that may have been partly selected by evolutionary pressures linked to fire use.

A Theory That Shakes Paradigms

This hypothesis challenges the idea that human evolution was primarily dictated by survival against predators or classic environmental pressures. It suggests that our own technologies -- and the risks they entailed -- may have become selective agents in their own right.

Olduvai Gorge in Tanzania
Olduvai Gorge (Tanzania), one of the most important paleoanthropological sites in the world. It is in similar contexts in East Africa that the first evidence of fire use by hominins was discovered.

If confirmed, the burn selection theory would add to an increasingly complex picture of human evolution: that of a species that not only adapted to its environment, but was partly shaped by its own culture -- in the most literal sense of the term.