The Passing of Neanderthal Man

An analysis of 40,000-year-old Neanderthal, human and animal bones suggests we outlived Neanderthals because of drastic climate change. Above, a wolf jaw fragment from Le Moustier, analyzed during an international study of Paleolithic-era European nitrogen isotope concentrations. Nitrogen isotopes increase in plants under arid conditions, which are then taken up by herbivores, who are in turn eaten by carnivores, passing the detectable isotopes upward through the food chain. Photo: Herve Bocherens, University of Tubingen

Approximately 40,000 years ago, the remarkably hardy, well-adapted and comparatively stronger species of hominids called the Neanderthals vanished virtually overnight, for reasons as yet shrouded in mystery. Analyses of skull brain cases show that, in addition to being physically stronger than modern humans, Neanderthals possessed a much larger occipital lobe, seat of the visual cortex. Therefore, in addition to superior strength and better physical adaptations to survive extreme cold, they likely had eyesight far superior to ours.

These factors make their abrupt disappearance from the archaeological record a remarkable mystery. Among the more unsettling possibilities, evidence suggests we might have eaten them. Less controversially, however, it's been posited that Homo sapiens' wider dietary tolerances meant a survival advantage over the Neanderthals. This theory seemed to have been borne out by chemical analyses of fossil hominid bones; human bones from the era are higher in nitrogen-heavy isotopes when compared with Neanderthal bones, pointing to a diet that included fish, as opposed to the Neanderthal big-game-meat diet, primarily mammoth and bison flesh.

The problem with these dietary studies is that they did not include the isotope content of the animals that were actually being consumed at the time. However, 2014 studies at Germany's Tubingen University and France's Musee national de Prehistoire focused on nitrogen isotopes in animal bones of the era - including those from carnivores such as prehistoric wolves, and ancient herbivores such as deer, bison, and horses.

The analyses show nitrogen isotopes increased dramatically throughout the food chain just as modern humans first began appearing in southwestern France. Because the sudden isotope increase in animals mirrors the one found in hominid bones from the same period, the territorial takeover by humans over Neanderthals isn't likely from simple dietary changes; instead, such a pervasive isotope increase appears to have arisen from major environmental change.

An arid environment is known to trigger increased nitrogen isotope concentrations in plants, and when those plants are consumed by herbivores, who are then eaten by predators, the isotopes circulate throughout the food web.

Because this surge in isotopic nitrogen coincides with the extinction of Neanderthals, it's believed that environmental changes like an increase in aridity may have pushed humans into a position of ascendancy in prehistoric European territories.

Source: Paleo diet didn't change? the climate did, News Release, March 17, 2014, Universitaet Tubingen
Note: This article is a copyright-protected excerpt from the 2014 revised edition of The Path Book I: Origins, to be published this September by Polyglot Studios, KK and available direct from this blog's author or on Amazon.com.