How did the people living in Japan come to be? Advancements in academic study methods may eventually clarify the origins of the Japanese people.
Progress is being made in introducing scientific methods for the study of prehistory, such as the Palaeolithic age and the Jomon and Yayoi periods.
One notable method is a genome analysis in which DNA is sampled from human bones so its genetic information can be read. Reading devices have been improved, and they are being utilized for prehistoric studies around the world.
A team of researchers from the National Museum of Nature and Science and other institutions has succeeded in analyzing the genome from the bones of a woman discovered in the Jomon ruins on Rebun Island in Hokkaido, which date back 3,500 to 3,800 years. The analysis could be made because her back teeth were fortunately preserved in good condition.
The woman was brown-eyed and dark-skinned. She was a heavy drinker and consumed fatty meat. The latest genome analysis has brought such features of the woman into relief. These findings can be described as a result that could not have been gained through conventional study methods, such as an analysis of stoneware and earthenware or observation of her bones.
It has also been found that about 10 percent of the genome of Jomon people has been inherited by the Japanese in the present Honshu region. This is very interesting when we think about the roots of contemporary Japanese people.
Regarding the origins of the Japanese, it has been widely accepted that Yayoi people of northeast Asian origin flowed into areas where Jomon people were living, which led to increased mixing between them. If genetic information about prehistoric people is further collected in various places, it will be possible to verify this theory.
Accuracy being enhanced
A group of scientists from the National Institute of Genetics and other organizations has started a project to analyze the genomes from bones from more than 100 ancient people. How did Jomon culture expand? What kind of relationship existed between Jomon and Yayoi people? The project can be expected to offer even greater details about prehistory.
Other scientific methods have also been developed. The tree-ring dating method using oxygen isotope ratios, which spread during the 2010s, is being utilized to analyze the oxygen contained in the growth rings of a tree unearthed from ruins, thereby identifying the date of the excavated artifact in units of one year.
The radioactive carbon-14 dating method is being used to determine the date of excavated artifacts, for example, by analyzing the soot stuck to earthenware. The method has been known for a finding made by the National Museum of Japanese History. Using the method, the museum reached the view that the start of the Yayoi period dates back to 3,000 years ago, as many as 500 years earlier than generally believed.
The radiocarbon dating method has become more accurate than it used to be. The method should be effectively used for prehistoric studies.
Our ancestors are believed to have migrated to the current Hokkaido, northern Kyushu and Okinawa areas in the Palaeolithic age. This summer, an ocean crossing was attempted from Taiwan to Yonaguni Island in Okinawa Prefecture by canoe, with a view to tracing a path followed by our ancestors.
Efforts should be made, through the use of various methods, to unravel mysteries surrounding prehistoric Japan.