Scientists discovered the ancestral roots of modern Japanese people.
Scientists have been studying the evolutionary history of humans for many years. They use fossil evidence, genetic data, archaeological artifacts, and so on to unravel the mysteries of our complex past. Through these efforts, they aim to gain a deeper understanding of our origins, our connections to other living things, and the intricacies of our own biology.
In a recent study published in Science Advances, a group of scientists from the RIKEN Center for Integrative Medical Sciences, the University of Tokyo, and Kanazawa University in Japan have identified the ancestral origins of modern Japanese people. They found that modern Japanese people descended from three ancestral groups: the Jōmon people (indigenous Japanese hunter-gatherers that lived from 14,000 BCE to 300 BCE), the East Asian ancient predecessors of the Han Chinese, and a previously unknown group of ancient people that seemed to have originated from Northeast Asia. This challenges the previous hypothesis that modern Japanese people arose from only two ancestral groups: the Jōmon people and the Yayoi people, a rice-farming society that lived from 300 BCE to 250 CE.
Furthermore, the scientists discovered that modern Japanese people have inherited 42 DNA segments from Neanderthals and two from Denisovans (Neanderthals and Denisovans were extinct species of humans). These segments are linked to complex traits, and they likely emerged from past interbreeding events between early Homo sapiens and the ancestors of modern Japanese people. Complex traits are those that are influenced by multiple genes. Some of the inherited complex traits uncovered in the study were type-2 diabetes, height, coronary artery disease, atopic dermatitis, prostate cancer, and rheumatoid arthritis.
According to the scientists, they made these discoveries after performing whole-genome sequencing on 3,256 samples from Biobank Japan. These samples came from seven regions of Japan, namely, Hokkaido, Tohoku, Kanto, Chubu, Kansai, Kyushu, and Okinawa. Afterward, the scientists collated their data and created a database called the Japanese Encyclopedia of Whole-Genome/Exome Sequencing Library (JEWEL). By analysing this database, they were able to “delve into uncharted territories concerning population and medical genetics of the Japanese population.”
With further studies, the scientists hope to have a better understanding of how modern Japanese people came to be. They are also planning to use JEWEL to develop medicines for certain diseases, including type-2 diabetes, coronary artery disease, atopic dermatitis, prostate cancer, and rheumatoid arthritis.
The full discussion of the study has been published in the peer-reviewed scientific journal Science Advances.