Nature of Research: Passey was part of an international team that analyzed the diet of Australopithecus sediba, a human-like primate that lived 2 million to 3 million years ago in what is now South Africa. Researchers used a laser to vaporize bits of fossilized tooth enamel from two individuals that had been recovered. Using mass spectrometry, they detected in the vapor the chemical fingerprints of the foods consumed. They found that these two Au. sediba ate mostly leaves, fruit and bark from the forest, even though they lived in a savanna rich in seeds, roots and grasses.
Stage of Research: Passey and colleagues published their findings in a letter to the journal Nature, which was posted online June 27. Passey's work was funded by the National Science Foundation, while others on the team received support from a variety of sources, including the Smithsonian Institution and the Leakey Foundation.
Implications: Knowing the diet of Au. sediba adds another piece to the emerging picture of how and when Homo sapiens evolved from pre-human ancestors, and why some primates may have gone extinct. Although apes like chimpanzees and gorillas are forest dwellers, humans "are basically grass eaters," according to Passey. Researchers are trying to pinpoint when in the distant past that dietary shift occurred.
Want to be featured in Research Buzz? Send information to email@example.com.