An extraordinary case in human history: Prehistoric hunter-gatherer adaptation to the islands of the Central Ryukyus (Amami and Okinawa archipelagos), Japan

Abstract

The islands of the Central Ryukyus (Amami and Okinawa archipelagos), Japan, were continuously occupied by hunter-gatherers for several thousand years during the Holocene. This occupation would seem to represent a unique example of island settlement by hunter-gatherers. Homo sapiens had expanded into all continents except Antarctica by 10,000 BP, demonstrating high adaptability to various environments, but few islands had been settled by that time. Most islands appear to have been too small to support hunter-gatherer subsistence. Many islands were indeed first colonized by agriculturalists. Some islands located close to large landmasses, having a large surface area, or with reliable sea mammal populations or translocated plants and animals were successfully colonized by hunter-gatherers, but none of these features characterize the prehistoric Central Ryukyu Islands, which were successfully colonized by hunter-gatherers by at least the early–middle Holocene. Furthermore, this colonization was likely accomplished with smaller populations and foraging territories than previously documented for hunter-gatherers. Coral reef resources with nuts (and possibly yams) appear to have played a crucial role in this island colonization. The only similar case to prehistoric Okinawa comes from the Andaman Islands, where hunter-gatherers have occupied small tropical islands for thousands of years. The final part of this paper provides a brief comparison of the Andaman data in light of the results from the Central Ryukyus described here.

Genomic history and ecology of the geographic spread of rice

“…Ancient DNA studies also suggest a wave of Austronesian human expansion into island Southeast Asia ∼2,000 years ago ( 41 ), which agrees with our estimates of japonica movement into the area. Interestingly, upland temperate japonica in Japan appears to be an admixed population of local lowland temperate rice and upland tropical rice from the Malay Archipelago which may have moved northwards through Taiwan and perhaps the Ryukyu Islands ∼1,200 yBP ( 46 ).…”

Towards a prehistory of the Great Divergence:

“…Rice paddy fields were constructed in Aomori in the northern Tōhoku in the 4 th century BC but rice growing in this region was quickly abandoned, only to return centuries later. Agriculture did not reach the Ryukyu Islands in the south until the 10 th century AD (Takamiya et al 2016). In Hokkaido, barley is known from sites of the Iron Age Okhotsk culture (Leipe et al 2017).…”

The Ryukyu Islands and the Northern Frontier of Prehistoric Austronesian Settlement

“…The islands in Okinawa Prefecture are usually divided into three cultural zones: the Amami Islands in the north near Kyushu, the Okinawa Islands in the centre, and the Sakishima Islands to the south closest to Taiwan (Figure 10.2). In the north, the Amami and Okinawa Islands as far south as Okinawa Main Island were settled by at least 6000 BP by Jōmon populations originating on Kyushu Island (Takemoto 2003;Pearson 2013;Takamiya et al 2016). To the south, the Sakishima Islands were inhabited by quite different cultures that will be discussed in more detail below.…”

“…One problem here, of course, is how the southern Ryukyu people apparently managed to maintain a 'strandlooper' (Groube 1971) subsistence strategy for thousands of years while elsewhere in the Pacific population growth led quickly to the re-adoption of agriculture. The high productivity of the coral reef foraging adaptation in the prehistoric Ryukyus was potentially a key factor here (Takamiya et al 2016). …”