This shift coincided with the retreat of heavily forested areas that were replaced by open savannah. A third study , also led by Cerling, used stable isotopes to analyze the diet of several species of Theropithecus , the ancestors of the modern gelada baboon, a grass-eating ape that lives in the highlands of Ethiopia. Like its descendant, Cerling and colleagues found that the ancient Theropithecus species almost exclusively ate C4 plants, similar to the diets of the modern geladas.
But although ancient Theropithecus and ancient hominins lived in the same area and both had a primarily C4 diet, they did not appear to be in direct competition with each other, Cerling noted, likely because they preferred different types of C4 plants. Finally, a review paper by Wynn, Cerling and colleagues analyzed what we know about ancient hominin diets. Big brains and upright walking are two of the main factors that distinguish humans from other primates, and it appears that a shift in diet from leaves to grasses may be a significant third factor.
Researchers are just beginning to understand what ancient humans ate, and these recent studies show that grasses and grains have been part of the human diet for millions of years. Carrie Arnold is a freelance science writer in Virginia. She blogs about the science of eating disorders at www. Register or Log In. According to an article in the latest issue of Science , our ancestors may have been more sophisticated eaters than we've been giving them credit for.
After analyzing starch residue on dozens of ancient stone tools found in a cave in Mozambique, archaeologist Julio Mercader of the University of Calgary came to a surprising conclusion. The residue was sorghum, a wild cereal grain. Previous archaeological evidence has suggested that grains entered the human diet perhaps 23, years ago and grain storage started more recently, around 11, years ago. Analyzing the surface of 70 of these tools, Mercader found some 2, granules of plant starch, which, he reasons, could not have accidentally come from growing plants in such dark reaches of the cave.
And the fact that so many of the tools had a coating is evidence of at least some processing to make the seeds more edible. Indeed, a descendent of the wild sorghum found on the tools still makes up a large portion of modern diets in sub-Saharan products including breads, porridge and even beer.
Other tidbits that these hungry humans appear to have been dining on during that period include the African false banana, pigeon peas, wild oranges, African wine palm and the African potato, the researchers concluded. These finds are "proof of an expanded and sophisticated diet much earlier than we believed," Mercader said. And grain consumption was the first step toward grains' domestication—and, eventually, cupcakes.
The views expressed are those of the author s and are not necessarily those of Scientific American. Already a subscriber? Until the past few years, these hard-to-analyse remnants of ruined meals were rarely given a second look. The first step towards changing that perception was to go back to the kitchen.
That was the inspiration of Soultana Valamoti, an archaeobotanist at the Aristotle University of Thessaloniki in Greece who, not coincidentally, is also a passionate home cook. Valamoti spent the early years of her career toting buckets and sieves from one excavation site to another across Greece, all while combing museum storerooms for ancient plant remains to analyse.
The work convinced her there was an untapped wealth of evidence in burnt food remains — if she could find a way to identify what she was looking at. More than 20 years ago, Valamoti decided to turn her lab into an experimental kitchen. By comparing the burnt remains to 4,year-old samples from a site in northern Greece, she was able to show that the ancient and modern versions matched, and that this way of preparing grain had its roots in the Bronze Age 3.
Credit: Soultana MariaValamoti et al. Over the decade that followed, she continued experimenting. Beginning in , a European Research Council grant allowed her to create a crusty, charred reference collection of more than types of ancient and experimental samples. After making bread dough, baked bread, porridge, bulgur and a traditional food called trachana from heirloom wheat and barley, Valamoti chars each sample in an oven under controlled conditions.
She than magnifies the crispy results by to 1, times to identify the tell-tale changes in cell structure caused by different cooking processes. Whether boiled or fresh, ground or whole, dried or soaked, the grains all look different at high magnification.
Baking bread leaves tell-tale bubbles behind, for example, whereas boiling grain before charring it gelatinizes the starch, Valamoti says. How did Neanderthals and other ancient humans learn to count? Comparing the ancient samples with her modern experiments, Valamoti has been able to go beyond identifying plant species to reconstruct the cooking methods and dishes of ancient Greece.
There is evidence that people in the region have been eating bulgur for at least 4, years 4. It was the fast food of the past. Other researchers are also pursuing ancient cooking mistakes. In the past, it has been difficult for researchers to find hard evidence that our distant ancestors ate plants. Genetic data support the idea that people were eating starch.
In , for example, geneticists reported 5 that humans have more copies of the gene that produces enzymes to digest starch than do any of our primate relatives. That genetic change in the human lineage helped to shape the diet of our ancestors, and now us.
Food remnants resembling bread were found in a hearth at the Shubayqa 1 site in Jordan. Credit: Alexis Pantos. To find supporting evidence in the archaeological record, Larbey turned to cooking hearths at sites in South Africa dating back , years, picking out chunks of charred plant material — some the size of a peanut. Under the scanning electron microscope, she identified cellular tissue from starchy plants 6 — the earliest evidence of ancient people cooking starch.
The evidence is remarkably consistent, she adds, particularly compared with animal remains from the same site. Early humans probably ate a balanced diet, leaning on starchy plants for calories when game was scarce or hard to hunt. Evidence suggests that plants were popular among Neanderthals, too.
In , Amanda Henry, a palaeoanthropologist now at Leiden University in the Netherlands, published her findings from dental plaque picked from the teeth of Neanderthals who were buried in Iran and Belgium between 46, and 40, years ago.
Plant microfossils trapped and preserved in the hardened plaque showed that they were cooking and eating starchy foods including tubers, grains and dates 7. Indigenous groups look to ancient DNA to bring their ancestors home. In May, Christina Warinner, a palaeogeneticist at Harvard University in Cambridge, Massachusetts, and her colleagues reported the extraction of bacterial DNA from the dental plaque of Neanderthals, including a ,year-old individual from what is now Serbia.
The species they found included some that specialized in breaking down starch into sugars, supporting the idea that Neanderthals had already adapted to a plant-rich diet 8.
0コメント