(Phys.org)—A team of researchers affiliated with several institutions in China has dated rice material excavated through a dig site in South China’s Zhejiang province back to approximately 9,400 years ago. In their paper published in Proceedings of the National Academy of Sciences, the group describes where they found the evidence of early rice, their testing in addition to also also dating techniques, in addition to also also what they found.
Various research groups through several countries in Asia claim to have found evidence of the earliest cultivation of rice as a food source. today, those claims may have been dispelled, as the team in China has found the oldest evidence yet of cultivated rice.
In This specific brand new effort, the researchers worked at a dig site near the Yangtze River called Shangshan—prior work there had uncovered some ancient pottery artifacts. The team found numerous samples of phytoliths, which are tiny bits of silica which some plants fashion to protect themselves against pests. Rice plants create fan-shaped phytoliths—they are made of silica, thereby do not digest, burn or decay over time. Specific patterns on the surface of the phytoliths offer evidence of the history of rice as which evolved through wild rice to today’s domesticated rice.
To date the phytoliths, the researchers collected enough samples through soil in areas where they found the ancient pottery shards in addition to also also then sifted, cleaned in addition to also also heated them to create a powder which could be carbon dated. Such testing showed the phytoliths to be approximately 9,400 years old. The team also studied the phytoliths under a microscope to note the patterns on their surfaces, which they report is usually neither like wild rice nor modern domesticated rice—instead, which was through a time period somewhere between the two. To add more credence to their discovery, the researchers also carbon dated various other materials from the same area in addition to also also depth, including seeds in addition to also also charcoal, in addition to also also found them to be roughly the same age.
The work by the team offers more evidence to bolster prior claims which Shangshan was one of the first places to cultivate rice, if not the first outright.
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“Dating rice remains through phytolith carbon-14 study reveals domestication at the beginning of the Holocene,” Proceedings of the National Academy of Sciences (2017). www.pnas.org/cgi/doi/10.1073/pnas.1704304114
Abstract Phytolith remains of rice (Oryza sativa L.) recovered through the Shangshan site from the Lower Yangtze of China have previously been recognized as the earliest examples of rice cultivation. However, because of the poor preservation of macroplant fossils, many radiocarbon dates were derived through undifferentiated organic materials in pottery sherds. These materials remain a source of debate because of potential contamination by old carbon. Direct dating of the rice remains might serve to clarify their age. Here, we first validate the reliability of phytolith dating from the study region through a comparison with dates obtained through various other material through the same layer or context. Our phytolith data indicate which rice remains retrieved through early stages of the Shangshan in addition to also also Hehuashan sites have ages of approximately 9,400 in addition to also also 9,000 calibrated years before the present, respectively. The morphology of rice bulliform phytoliths indicates they are closer to modern domesticated species than to wild species, suggesting which rice domestication may have begun at Shangshan during the beginning of the Holocene.