The finding of a series of roasted stems proves that humans already cooked plants at least 170,000 years ago. The samples would be rhizomes or tubers of a kind of potato. Although they can be eaten raw, they multiply their nutritional contribution once cooked. For the authors of the discovery, the scorched remains of photography must have been a fundamental part of the diet and human evolution itself.
"These are the underground parts of the oldest edible plants found in the world," says the researcher at the Institute for Evolution Studies at the University of the Witwatersrand (Johannesburg, South Africa) and principal author of the research, Lyn Wadley. The observation under the microscope and its comparison with several current species has allowed Wadley and his colleagues to determine that 55 of the analyzed samples would be rhizomes of Hypoxis angustifolia, a plant that belongs to the genus of African potatoes. "They are still eaten today in many rural areas of Africa cooking on the embers of a bonfire," he adds. In fact, the remains found in a cave in the Lebombo mountain range in northeastern South Africa were among the ashes of a fire.
Thanks to several dating techniques and their position in the stratum, the authors of the study estimate that the stems were roasted about 170,000 years ago, with a margin of error of a few thousand years. "Even older seeds have been found in other deposits"Wadley clarifies." But the relevance of the rhizomes of Hypoxis they are rich in starch (like potatoes) and highly nutritious, "adds the veteran archaeologist.
The rhizomes of Hypoxis angustifolia they still roast and eat in many rural areas of Africa
Starch is the reserve carbohydrate of most vegetables and in the human intestine it has a vital role. As the South African researcher recalls, African game meat is very lean and low in fat, especially in the dry season. "Lean meat proteins cannot be metabolized by humans if carbohydrates or fats are not involved," he says. So the incorporation of the sugars of the rhizomes of H. angustifolia would have allowed the first Homo sapiens Process proteins and get a more balanced diet.
Lyn notes a minor appearance: "Once cooked, they are easier to peel and the fiber decomposes, making the rhizomes more digestible. Those benefits should have been relevant for the group's elders and for the little ones." On this fact he argues: "Being the most vulnerable members, they would not be part of the outings to be collected, having to wait in the cave. The fact that the food was transported to the home and then cooked provides extra information about social behavior and how they shared 170,000 years ago. "
The authors of the research, published in Science, provide another element in their conclusions. Humans need a minimum of 100 grams of carbohydrates a day for their star organ, the brain, to function optimally. With these rhizomes they could meet your needs. "From the bones of animals that we have found, we know that the inhabitants of the cave also ate meat," says Lyn and adds: "The Homo sapiens they have big and demanding brains [en energía], but small intestines (compared to previous hominins). The only way to maintain this relationship was to eat high quality food. "Lyn also remembers that the Hypoxis angustifolia it occurs in almost all of Africa, so it could well be a support in human expansion across the continent and beyond.
"From the nutritional point of view it is not surprising that the hominids who frequented this settlement chose these rhizomes as a fundamental part of their diet since they have a high caloric content, necessary to support such active populations of hunter-gatherers," says the researcher from the British Museum Lara González Carretero. "However, from the archaeobotanical point of view it is very interesting since it confirms the human consumption of rhizomes and tubers from a very early age and not only the consumption of meat," adds this scientist, not related to the study.
However, González Carretero does not rule out the possibility that these rhizomes were burned accidentally or as firewood. The same question arises archeobotany of the University of Copenhagen (Denmark) Amaia Arranz-Otaegui, also oblivious to this research. Although it highlights its relevance, remember that in prehistoric homes there is not only food, but also vegetable fuels and other plant remains that "could be there before combustion itself." Both scientists believe that more studies should be done on the samples to determine if they were prepared before cooking. Otherwise, the central argument of the study would not be sustained and it would only be about old scorched rhizomes.