**1. Introduction**

Intensive immigration to the island is a tremendous environmental adaptation achieved by *Homo sapiens* [1]. Recently, pre-sapiens hominin has been reported to enter the islands [2–4]. But *H. sapiens* has been much more aggressive in immigrating to the islands, especially relatively small and remote islands [5], and utilization of marine resources even at the late Pleistocene [6–10]. Intensive colonization to the island demands complex planning and technological innovation such as seagoing craft, navigation on the ocean, adaptation to unfamiliar fauna, flora, and landscapes [1, 5].

The Ryukyu Islands are one of the oldest oceanic islands to which Pleistocene people immigrated, comparable with the islands of Southeast Asia [1, 11]. Early modern humans inhabited this area no later than 30,000 years ago and probably earlier than 36,500 years ago [1, 11, 12]. The Paleolithic sites cover most of the relatively large islands of this area (**Figure 1**, **Table 1**). The human remains found in this area consist of male and female adults, and children [13–16]. These facts suggest the intentional voyages of early modern humans with their families to the islands.

In Australia, researchers found evidence of the oldest voyage in the world from the islands of Southeast Asia; that voyage occurred earlier than 50,000 years ago [17, 18]. The maritime technology for open sea fishing seems to have been developed prior to the journey, as reported in the case of Timor [19]. Although the use of aquatic resources by early modern human developed before Out-of-Africa,

#### **Figure 1.**

*Paleolithic sites of the Ryukyu archipelago. The white circle represents the sites with stone tools, and the black circle represents the sites with human remains. The dark gray area represents the current land, and the light gray area represents the contour at 120 m depth.*


**135**

out the Pleistocene.

(<1207 km2

*The Migration, Culture, and Lifestyle of the Paleolithic Ryukyu Islanders*

much earlier than 100,000 years ago [20–22], the populations who came to Islands Southeast Asia (ISEA), in the course of the worldwide dispersal of early modern humans, may have developed much more extensive uses of marine

Paleolithic people to advance into the island environment beyond the tropical zone. The Ryukyu Islands consist of relatively small islands that are distributed on the margins of the tropical to temperate zone, and which are isolated from each other and mainland Japan. Natural resources such as stone materials and terrestrial animals differ among the islands. Between 30,000 and 36,500 years ago, Paleolithic people immigrated to these variable islands, which spread over 1200 km. Their entry into these diverse environments for a relatively short period provides evidence of the malleable behavior of the early modern humans who adapted to these islands. The purpose of this paper is to review the Paleolithic archeological sites of the Ryukyu Archipelago and to clarify how people adapted to sub-tropical remote islands with limited resources, especially in contrast with the ISEA, thus providing

the basis for the global distribution of Paleolithic people.

**2. Geographic setting and paleofauna of the Ryukyu Islands**

The chain of Ryukyu Islands stretches roughly 1200 km between Kyusyu Island

) are dispersed from the northeast to the southwest at roughly 27° north

of Japan and Taiwan in the west Pacific. More than 150 relatively small islands

in latitude (**Figure 1**). A dry and sandy climate generally exists at this latitude around the world, but the Ryukyus are covered with subtropical forests nourished

Previously, the Ryukyu Islands were at the eastern end of the Eurasian continent. The tectonic plate movements of the Eurasian and Philippine plates formed the deep ocean basin named the "Okinawa trough" to the west of the Ryukyus and divided the islands from the continent. This geological event probably occurred no later than the early Pleistocene [27]. Today the islands are divided into three parts by the sea, which is over 1000 meters deep: the northern, central, and southern Ryukyus. Some of the northern Ryukyu Islands were connected to the Kyushu Island of Japan during the Last Glacial Maximum (LGM) around 20,000 years ago. The fauna and prehistoric culture of these islands were closely related to those of Kyusyu. By contrast, the central and the southern Ryukyus were isolated through-

The islands now are located at the margin of two biogeographic areas: the Oriental and Sino-Japanese regions [28]. The fauna and flora of the Ryukyus

by the hot and humid atmosphere created by the Kuroshio ocean current.

Developed maritime technology and flexible resource usage would have enabled

**the island**

**Age of the oldest layer**

Ishigaki 223 km2 27k Four

Pinza-abu Miyako 158 km2 29k~32k Partial

**Artifacts Human** 

**remains**

adult(s)

adults and more (18k~27k)

*DOI: http://dx.doi.org/10.5772/intechopen.92391*

Shiraho-Saonetabaru Cave

*Paleolithic sites of the Ryukyu Islands.*

**Region Site Island Area of** 

resources [19, 23–26].

Southern Ryukyus

**Table 1.**



#### **Table 1.**

*Pleistocene Archaeology - Migration, Technology, and Adaptation*

*Paleolithic sites of the Ryukyu archipelago. The white circle represents the sites with stone tools, and the black circle represents the sites with human remains. The dark gray area represents the current land, and the light* 

**the island**

**Age of the oldest layer**

444 km2 35k Cobble tools,

444 km2 35k Cobble tools,

712 km2 >30k? Shale flakes

712 km2 30k? Chert flakes

248 km2 >30k? Chert flakes

248 km2 >30k? Granite and

Okinawa 1,207 km2 36k Sandstone

Minatogawa Okinawa 1,207 km2 20k~23k Four

Shimojibaru Kume-jima 56 km2 18k Infant

Sakitari Cave Okinawa 1,207 km2 35k Shell artifacts

**Artifacts Human** 

grinding stones, polished adze blades, flakes

grinding stones, flakes, anvil stones

sandstone cobbles

cobbles

and sandstone (whetstone) (23k~20k) Quartz flakes (16k~14k)

**remains**

Partial infant

Partial adults and infants (14k~16k, 23k, 30k)

adults

**134**

**Figure 1.**

Northern Ryukyus

Central Ryukyus

*gray area represents the contour at 120 m depth.*

**Region Site Island Area of** 

Tachikiri Tanega-

Yokomine C Tanega-

Kishikawa Amami-O-

Amangusuku Tokuno-

Garazo Tokuno-

Tsuchihama-Yaya

Yamashitacho Cave 1

shima

shima

shima

shima

shima

Amami-Oshima

*Paleolithic sites of the Ryukyu Islands.*

much earlier than 100,000 years ago [20–22], the populations who came to Islands Southeast Asia (ISEA), in the course of the worldwide dispersal of early modern humans, may have developed much more extensive uses of marine resources [19, 23–26].

Developed maritime technology and flexible resource usage would have enabled Paleolithic people to advance into the island environment beyond the tropical zone. The Ryukyu Islands consist of relatively small islands that are distributed on the margins of the tropical to temperate zone, and which are isolated from each other and mainland Japan. Natural resources such as stone materials and terrestrial animals differ among the islands. Between 30,000 and 36,500 years ago, Paleolithic people immigrated to these variable islands, which spread over 1200 km. Their entry into these diverse environments for a relatively short period provides evidence of the malleable behavior of the early modern humans who adapted to these islands. The purpose of this paper is to review the Paleolithic archeological sites of the Ryukyu Archipelago and to clarify how people adapted to sub-tropical remote islands with limited resources, especially in contrast with the ISEA, thus providing the basis for the global distribution of Paleolithic people.
