"This has implications for the future of our planet as climate and ecology change as a result of human activities not only climate change, but land-use change such as agriculture and desertification," he adds. "And it is not always possible to predict how different parts of the ecosystem will respond to any of these changes."
Uno and Cerling did the study with John Harris of the George C. Page Museum in Los Angeles; paleontologist Meave Leakey of Kenya's Turkana Basin Institute based at Stony Brook University in New York; and Japanese scientists Yutaka Kunimatsu and Masato Nakatsukasa of Kyoto University, and Hideo Nakaya of Kagoshima University.
You are What You Eat: True 10 Million Years Ago
You are what you eat and the same was true for African animals that lived millions of years ago. Their diets were recorded by carbon isotope ratios in the enamel of their now-fossilized teeth. The ratios reveal whether an animal ate plants that used so-called C3 or C4 photosynthesis to convert sunlight to energy.
C3 plants include trees, shrubs and cool-season grasses. Most C4 plants are warm-season grasses and sedges commonly found in the tropics. Today in East Africa, nearly all grasses are C4 grasses. And, for the record, modern hays often mix C3 and C4 plants.
Dietary carbon is incorporated into tooth enamel, letting researchers determine whether long-dead animals grazed on C4 grasses or browsed on C3 trees and shrubs.
Global or regional changes in climate have the potential to transform a forest into grassland or vice versa. When this happens over large areas, animals must change their diets or deal with the consequences, which in extreme cases might mean moving to a new habitat or eventually going extinct.
The diet record of East African herbivores from 10 million to 3 million years ago shows dramatic change occurred at different rates and times. The change was a shift from eating
|Contact: Lee Siegel|
University of Utah