"We study tooth enamel because it's the hardest mineral in the body and preserves its chemical and isotopic signatures over time, so it has a lot to tell us," Passey explains. "We couldn't get the same analysis from a bone fragment, for instance, because it will be affected by the composition of the soil surrounding it."
Passey and the team concluded that Au. sediba consumed between 95 and 100 percent forest-based foods, despite other foods easily available to them.
Why is this important to know?
"Well, one thing people probably don't realize is that humans are basically grass eaters," he said. "We eat grass in the form of the grains that we use to make breads, noodles, cereals and beers, and we eat animals that eat grass. In America, we eat animals that are fed corn, and corn is grass, albeit one with an incredible history of human selection. So when did our addiction to grass begin? At what point in our evolutionary history did we start making use of grasses? Eating grasses is a hallmark of humanity, and we are simply trying to find out where in the human chain that begins."
|Contact: Lisa DeNike|
Johns Hopkins University