Isotopes: Restoring Ancient China on the Tip of the Tongue

Stable isotopes in human bones (teeth) record the codes of human life, which can help researchers explore the history of human evolution and civilization evolution. Hu Yaowu glimpsed the evolution of ancient human food structure from the perspective of stable isotopes, and used precise research data to reveal a corner of evolution history for the audience.

What is the exactly connection between the human body and food?

“Natural foods naturally have differences between isotopes. When these animals and plants are digested and absorbed by humans, they will be transformed into components of bones.” Hu Yaowu said. In order to illustrate this problem, he brought the laboratory’s limb bones, ribs and teeth samples and the collagen and hydroxyapatite extracted from them to the scene for display.

It turns out that our bones and teeth are mainly composed of organic substances such as collagen and inorganic substances such as hydroxyapatite.

Stable isotopes are passed along the food chain to these tissues. Teeth, in particular, are like the annual rings of trees, which faithfully record the information of food ingested by living organisms throughout their lives. Through the chemical analysis of bones and teeth and the study of the stable isotope ratios in these components, the source of food eaten by humans can be traced, and the eating habits of the individual at that time can be deduced.

There are differences in the stable isotope ratios of different types of food, reflecting the “Birds of a feather flock together” at the food level. The differences in food sources and living styles of ancient humans made the stable isotope ratios in different periods and regions very different. Therefore, through the analysis and comparison of stable isotope data of the population, it is possible to distinguish between populations with different living styles, and realize the “group classification of people” from the perspective of isotope. This is the theoretical cornerstone of stable isotope analysis.

Stable isotopes in organisms in the biological world can be regarded as a hidden language. The interpretation of “isotope language” can help us uncover the mysteries of life hidden in living organisms and explore the mystery of their life and death.

Hu Yaowu introduced his research on the feeding behavior and ecological environment of Gigantopithecus blacki from the perspective of stable isotopes.

Gigantopithecus blacki was the largest primate ever to have appeared on Earth. Through the study of C, O, and Ca stable isotopes of his teeth, he found that these data are very characteristic and highly concentrated, which are quite different from other ancient humans and existing great apes. The choice of food for the Gigantopithecus blacki is too single, and the habitat is relatively narrow, which directly affects the survival of the Gigantopithecus blacki species,” Hu Yaowu said with a smile, “This shows that picky eaters have no good end.

The fate of the late Homo sapiens and the Gigantopithecus blacki is just the opposite. Hu Yaowu used isotopes to analyze C, N, and S stable isotopes of Tianyuandong people in Beijing (late modern humans about 40,000 years ago), and proved for the first time in the world that modern humans in later periods had ingested a large amount of Freshwater resources provide new scientific evidence for understanding the “broad-spectrum revolution” of the food structure of late Homo sapiens living in my country.

The intake of a large amount of aquatic food (including fresh water and sea water) provided a large amount of unsaturated fatty acids for late Homo sapiens, which is of great significance in promoting the development and evolution of the human brain. “Knowing how to eat” is an important reason why late Homo sapiens spread all over the world.

The analysis of human bone isotopes in many archaeological sites in my country from the Neolithic Age to the historical period shows that millet farming is not only the material basis for the formation of Chinese civilization, but also the food culture gene of the Chinese nation, which plays an important role in promoting the integration of ethnic groups and the community of the Chinese nation. formation plays an important role.

It closely connects the fate of ancient nomadic peoples and farming peoples, and is the “glue” for the exchange and integration of ancient Chinese nationalities, laying a material and cultural foundation for the integration of nationalities and the formation of the Chinese nation.

About 5,000 years ago, the entire Eurasian continent began the process of food globalization. Hu Yaowu’s team made a “food map” based on the isotope data of human bones in archaeological sites across the Eurasian continent: People in the Yellow River Basin in China mainly ate millet crops; In Xinjiang and Central Asia, wheat and millet are mixed food; European populations also sometimes consume millet crops. Obviously, the human bone isotope data clearly reflect the continuous westward radiation of millet crops from the Yellow River Basin to Central Asia and Europe.

“This is an isotope road that we sketched for the westward spread of millet, revealing the important impact of the spread of millet crops on human society in Central Asia and even Europe.” Hu Yaowu believes that compared with the Silk Road, it spans the entire European Millet crops in the subcontinent are actually the earliest witnesses of cultural exchanges between the East and the West.