Paper short abstract:

I re-examine the conclusions of Unger 2001 in light of research over the past two decades. In particular, the probability of substratal influences on proto-Japanese has been greatly reduced by new proto-Korean-Japanese.

Paper long abstract:

In Unger 2001, I pointed out that a serious weakness of theories asserting that proto-Japanese was spoken in Japan during the Jōmon period was that they took no account of cataclysmic volcanic eruptions. such as the explosion that created the Kikai caldera in ca. 5300 BCE. Archaeological evidence indicates that this event devastated “most of south and central Kyushu, which was not repopulated for many centuries.” Coupled with the decline in population toward the end of the Jōmon period evidenced by other archaeological finds, it is highly unlikely that seeds of proto-Japanese were planted in Japan in Jōmon times. Likewise, the area controlled by the kingdom of Bohai (K Parhae, 698–926 CE) was devastated by an eruption of Baitoushan (K Paektusan, on the Chinese-Korean border) some time between ca. 920 and 1020; whether the eruption obliterated the kingdom or coincidentally occurred soon after its demise, the Korean and Tungusic speakers now living there are unlikely to be the descendants of the subjects of Bohai or its predecessors.

In this paper, I re-examine the conclusions I drew in 2001 in light of research over the past two decades in historical linguistics, genetics, and archaeology. The likelihood that proto-Japanese was first spoken in the islands in the Early Yayoi period has increased. The dating of Early Yayoi, previously estimated at ca. 400 BCE, is now generally thought to have been ca. 1000 BCE. The probability of substratal influence of Jōmon-period speech on early forms of Japanese has diminished as better proto-Korean-Japanese etymologies have been proposed and evaluated (Unger, 2009, Francis-Ratté 2016, Francis-Ratté & Unger 2020) and the study of historical phonology has given us a better understanding of how varieties of proto-Japanese first diverged (de Boer 2010, 2020).