Ancient Japan can be split into three key time periods ... "We are very excited about our findings on the tripartite [three-part] structure of Japanese populations," lead author Shigeki Nakagome ...

The team compared them to adult skulls from two other ancient Japanese groups — Jomon and ... the skull depressions and overall changes in bone structure corresponded with examples of extreme ...

The ancestral roots of the modern Japanese population have been explored through many different hypotheses, the longest being the dual structure model that was ... in a time known as the Yayoi period.