Scientists have found that an early human relative named Australopithecus sediba, native to present day Johannesburg in South Africa, mostly ate leaves, fruits, nuts and tree bark. The discovery is surprising because the pre-human's habitat had a rich variety of tubers, sedges and small animals, all of which A. sediba seemingly ignored.
Using a laser to extract bits of fossilized tooth enamel, the scientists looked at the ratio of two forms of carbon: carbon-12 and carbon-13. A reading heavy in carbon-12 indicates a diet comprising mostly forest foods, such as leaves and fruits, and a reading heavy in carbon-13 signals a diet that included larger amounts of savanna foods such as seeds, roots and grasses. Although the creature lived in rich savanna, it ignored much of the food available and ate mostly forest foods, similar to a chimp and very much unlike other human relatives in the same region.