From Tree-Living to Tree-Eating: Human Ancestors Ate Bark

By Sophie Bushwick | July 2, 2012 4:34 pm

tartar on teeth
Tartar on the teeth of a young male Australopithecus sediba

To someone in the dentist’s chair, plaque is an unwelcome discovery, but to paleoanthropologists, it’s a gold mine of information. And the hardened plaque, called tartar or calculus, on the teeth of two Australopithecus sediba individuals revealed that these early humans had a taste for trees that included not only fruit, but also bark, wood, and leaves.

Researchers recovered the 2-million-year-old remains of two A. sediba, a species from which some scientists suspect modern humans descended, from a site in South Africa. By analyzing the physical wear, chemical makeup, and tartar content of the teeth, paleoanthropologists could determine what this proto-human usually ate. For example, the ratio of different carbon isotopes in the teeth suggested that they preferred to consume forest food rather than the grassland pickings that other early humans enjoyed. The tartar, meanwhile, contained plant particles linked to bark and woody material. But bark may not have been the hominins’ first food choice: modern primates tend to eat it only when tastier food is unavailable. Perhaps, the researchers suggest, these early humans had to deal with drought or a similarly stressful environment.

[via Scientific American]

Image courtesy of Amanda Henry / Nature

  • dcwarrior

    Was there any evidence they were using their teeth to make tools rather than eating the wood?

  • Bull Shirt

    Adirondack is derived from the Mohawk Indian word atirú:taks, literally meaning “tree eaters”.

  • ToothPick

    Maybe they were using wooden toothpicks, or just liked chewing twigs for taste or relaxation or cleaning.

  • Iain

    Maybe they learned how to smoke weed and got the munchies and ended up chewing on the trees. Like, man, uh, Hostess and Lays and them others were a long way in the future and they were, like, hungry, NOW!


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