Why Australopithecus sediba could rewrite our evolutionary history
Baku, July 16 (AZERTAC). Just under two million years old, Australopithecus sediba has attracted attention ever since its 2008 discovery because of its mix of ancient and modern traits. It's been hailed as the direct ancestor of the Homo genus...but that might be impossible.
What makes sediba's placement in our evolutionary family tree so difficult is where it came from. Paleoanthropologist Lee Berger and his team at Johannesburg's University of the Witwatersrand found the specimen in the caves of South Africa, which places it very far away from the East African locations of most key Homo discoveries - including a few isolated finds that seem to predate Australopithecus sediba.
Scientific American has an excellent, lengthy overview of both the discovery of sediba and the fierce, ongoing anthropological debate about whether it really is the ancestor of Homo or essentially just an evolutionary dead end that just happens to have some Homo-like features. This passage gives some sense of just how complicated it is to sort out this mystery, and how these anthropologists do not mince their words in questioning their opponents' arguments.
The team comprised nine scientists from across the globe. Lead author was Amanda Henry of the Max Planck Institute for Evolutionary Anthropology in Germany, a specialist in dental calculus and plant remains. Other specialists on the multi-disciplinary team included dental microwear specialists, isotopic specialists and phytolith researchers - scientists who study the physical remains of ancient plants.
Using isotope analysis, dental microwear analysis and phytolith analysis, the researchers closed in on the diet of these two individuals, and what they found differs from other early human ancestors from that period. The microwear on the teeth showed more pits and complexity than most previously studied australopiths. Like the microwear, the isotopes also showed that the animals were consuming mostly parts of trees, shrubs or herbs rather than grasses.
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