Recently, a number of studies have linked biodiversity to linguistic diversity.
In regions with high biodiversity, there is always (generally) high linguistic diversity as well.
There are a number of discrepancies, however, the most surprising being this:
Japan has very high biodiversity, yet with the exclusion of the Ryukyuan languages, spoken only in the Ryukyu Islands, and of Ainu (once spoken in n. Honshu, Hokkaido, etc), there is only one language indigenous to Japan.
How can this be explained? *IS* there an explanation?
My answer: yes, yes there is.
Japanese historical documents such as Kojiki, Nihonshoki, Nihongi, etc., indicate that what is now Japan was once very ethnically diverse and that there were many indigenous peoples.
A list of some of them (but by no means all) of them follows:
- Agumo
- Emishi
- Ezo (modern-day Ainu)
- Hayato
- Koshijin
- Kumabito
- Kumaso
- Kuzu
- Mishihase
- Roushi
- Saeki
- Santanjin (modern-day Nivkhs)
- Tsuchigumo
- Yamato (generally believed to be modern-day Japanese)
Some people would include Azuma, who are believed to have mixed with Baekje immigrants from the Korean Penninsula to form the Yamato culture/language/race.