This is a layman's research into Japanese ancient history as related to Ainu language. I have long been interested in a theme, "how Japanese language has emerged." There is no widely accepted answer to this question.
Perhaps, a conservative average is somewhere around that the language was a mixture of northern and southern languages as follows.
|in that a certain degree of vowel harmony can be observed in Old Japanese
|in that a few "body" related words show similarities to them.
Radical, so look they to me, opinions have been pubilshed by even well-known scholars, to a disappoinment by the many. Languages associated as the mother language to Japanese include Hebrew, Sumerian, Lepcha (a Himalayan language) and Tamil.
It is even astonishing why these serious scholars did not look at their own foot step, Ainu language.
Should we not place more focus on only other language that survived in the country through the long history? Should we not consider the Ainu language the strongest candidate for the language the native girl was speaking?
Let me talk briefly about three most important history books, in my opinion, that our ancestors left for us. Namely,
|compiled in AD 712 (Kojiki books in English)
|compiled in AD 720
|the oldest date recorded is AD 733.
The story let us know clearly that there were people already living in Japan when the royal family "descended" some time ago, say, claimingly, 2000 to 3000 years ago.
The royal marriage between Ninigi and Kono-Hana brought 3 sons of which the youngest took the royalship and the oldest became the ancestor of "Hayato" tribe, the books say.
My hypothesis is that Hayato was also an ancestor of people now known as Ainu . Such research as small deviation in head bones or comparison of dogs support my hypothesis positively. A certain blood type research is median to negative.
Here is a link to Page 11: Recent Anthropological Findings
More details at Pages 10,10a,10b: Introduction to works of Shichiro MURAYAMA (1908-1995)
Among other researchers, I have learnt that such persons as HATTORI Siro, KINDAICHI Kyousuke, CHIRI Mashiho and YAMADA Hidezo left remarkable works for followers in Ainu language studies. Very brief description about their works is given in Page 6.