Most apes eat leaves and fruits from trees and shrubs. New
studies spearheaded by the University of Utah show that human ancestors
expanded their menu 3.5 million years ago, adding tropical grasses and sedges
to an ape-like diet and setting the stage for our modern diet of grains,
grasses, and meat and dairy from grazing animals.
In four new studies of carbon isotopes in fossilized tooth
enamel from scores of human ancestors and baboons in Africa from 4 million to
10,000 years ago, a team of two dozen researchers found a surprise increase in
the consumption of grasses and sedges – plants that resemble grasses and rushes
but have stems and triangular cross sections.