**1. Introduction**

Most archeological evidence of the earliest anatomically modern human (AMH or *Homo sapiens*) migration and maritime adaptation in the Asian region, including maritime Asia such as Wallacea and Japan, are dated to after 50 ka and mainly after 40 ka. The term "Wallacea" refers to Alfred Russel Wallace who proposed a zoogeographic boundary line of the animal species of Asia and Oceania, which runs between Lombok and Bali, Borneo/Kalimantan and Sulawesi [1] and is now known as the Wallace Line. This zoogeographic line was soon after extended to the North and between Palawan Island and other Philippine islands by Thomas Henry Huxley and is known as Huxley's modification of the Wallace Line or simply Huxley's Line (**Figure 1**).

We recognize Wallacea as the archipelago between east of the Wallace-Huxley line and west of New Guinea and Australia that were part of the old continent of Sahul in Oceania. Geographically, Wallacea includes most of the Philippines except

on charcoal from a hearth feature and associated with Fox's "Flake Assemblage III" [11], with dates between 39 and 33 ka [12]. Meanwhile, Niah Caves in Borneo Island, located southwest of Palawan and part of Pleistocene Sundaland, provided the earliest radiocarbon evidence of modern human presence with a number of AMS 14C dates ranging from 49 to 44 ka cal. BP [13]. Also, old sites associated with AMH were found in Australia and New Guinea, which formed Sahul land in the past. Madjedbebe site in Australia provides OSL dates of early modern human occupation over 60 ka [14, 15], while Kosipe Mission site in New Guinea Highland provides 14C dates of 49-44 ka [16]. All these current evidences taken together indicate the early appearance of AMH in Island Southeast Asia (ISEA) including Wallacea and Oceania could date back to around 50-47 ka, when they migrated by

*Island Migration, Resource Use, and Lithic Technology by Anatomically Modern…*

*DOI: http://dx.doi.org/10.5772/intechopen.93819*

In maritime Asia, another region where early modern humans were required to cross the sea to migrate, are the islands of central and southern Japan. While the large northern island, Hokkaido was partly connected with the continent, the deep Tsugaru Channel formed a sea gap between Hokkaido and Honsyu to the south. Honsyu and Kyusyu were partly connected with each other, although they were never connected to the Korean peninsula during glacial periods and a gap of at least 50 km remained. The chronology from over 100 sites in Honsyu Island now dates back to around 40 ka [17]. The southern part of Japan is mainly composed of the Ryukyu Islands. Most of the islands in Ryukyu were 100-200 km away from each other and the early traces of AMH are currently dated to around 30 ka. Such archeological data tentatively show that the early sea crossings of 50 km distance by *Homo sapiens* to the Japanese Islands could be as old as 40 ka, while the migration into the remote islands in Ryukyu Islands by sea crossing with 100-200 km distance

Although the early AMH migrations to Wallacea and Sahul could be slightly older than the migration to the Japanese Islands, both cases demonstrate new abilities and skills of AMH or *Homo sapiens* to colonize different island sizes and environments in maritime Asian regions. Based on such understanding, this paper firstly summarizes (1) possible early migration routes and dates as well as their lithic and resource use into Wallacea by AMH, then (2) reports some latest

archeological cases by our archeological investigations in Wallacea and (3) discusses possible AMH island adaptations and migration strategies in Wallacea during the

When following the current archeological traces, only modern humans had reached Sahul and Oceania by sea crossing via Wallacea. There are some evidences of earlier human species in Luzon, Sulawesi and Flores in Wallacea [5, 8, 19] but there are no traces of early humans before *Homo sapiens* in other islands so far. The possible traces of early human species, including *Homo floresiensis*, indicate that *Homo sapiens* was not the first species to reach Wallacea, though all other evidences tentatively indicate that it was only *Homo sapiens* who colonized most of Wallacea, including its remote and small-sized islands. From this understanding, one of the most significant topics for the early modern human migration into Wallacea and Sahul is to investigate the maritime technology and capacity to adapt to changing environments that enabled early *Homo sapiens* to colonize islands in Wallacea and

For early human migration from Wallacea into Sahul, there are basically two major routes that have been suggested as "northern" routes from Sulawesi to

Pleistocene with comparative view of other island regions in the world.

**2. Human migration and dispersal into Wallacea and Oceania**

open sea crossing to the islands in Wallacea and to Sahul in Oceania.

commenced around 30 ka [18].

Sahul.

**87**

#### **Figure 1.**

*Major Pleistocene sites in and around Wallacea Archipelago with Wallace Line. Image reproduced from the GEBCO world map 2014, www.gebco.net.*

Palawan and East Indonesian islands including Timor Island - divided into Indonesian West Timor and independent East Timor (or Timor Leste). Currently, the oldest possible traces of AMH in Wallacea appear in several sites in Timor around 44 ka and 42 ka [2, 3], as well as rock art dated to as early as 44 ka on the basis of uranium-series dates of overlying speleothems in South Sulawesi [4].

In Flores Island, Liang Bua provides a long sequence of human presence over 90 ka, though the site was originally occupied and used by a small-bodied species known as *Homo floresiensis* [5, 6], who was possibly related to the *Homo erectus* group, and their early migration could have been before 840 ka by crossing at least 19 km distance of sea gap. Although the upper layers of Liang Bua provide evidence of modern human occupation, the exact date of boundary between modern humans and *Homo floresiensis* is yet unclear and estimated to be around 50 ka by the excavation team [7]. Similarly, in the Philippines the presence of fossils attributed to a small-bodied hominin dubbed "*Homo luzonensis*" was found in Callao Cave, Northern Luzon, and dated to c. 67-50 ka [8]. Currently, the earliest evidence for the appearance of modern humans in the Philippine islands east of the Wallace-Huxley line comes from several AMS 14C-dates ranging between 28 and 35 ka cal. BP that were retrieved from shell midden deposits at Bubog 1, a rockshelter on Ilin Island in Mindoro Occidental [9]. An earlier human presence is indicated by cultural and faunal remains in deposits underneath the radiocarbon-dated layers.

On the Sundaic part of the Philippines, Tabon Cave in Palawan Island has delivered ancient fossil remains of modern humans, and several U-series directly date them to an age as early as c. 47 ka [10]. However, the dates' high standard errors raise doubts on their reliability. Probably more accurate are recent AMS dates *Island Migration, Resource Use, and Lithic Technology by Anatomically Modern… DOI: http://dx.doi.org/10.5772/intechopen.93819*

on charcoal from a hearth feature and associated with Fox's "Flake Assemblage III" [11], with dates between 39 and 33 ka [12]. Meanwhile, Niah Caves in Borneo Island, located southwest of Palawan and part of Pleistocene Sundaland, provided the earliest radiocarbon evidence of modern human presence with a number of AMS 14C dates ranging from 49 to 44 ka cal. BP [13]. Also, old sites associated with AMH were found in Australia and New Guinea, which formed Sahul land in the past. Madjedbebe site in Australia provides OSL dates of early modern human occupation over 60 ka [14, 15], while Kosipe Mission site in New Guinea Highland provides 14C dates of 49-44 ka [16]. All these current evidences taken together indicate the early appearance of AMH in Island Southeast Asia (ISEA) including Wallacea and Oceania could date back to around 50-47 ka, when they migrated by open sea crossing to the islands in Wallacea and to Sahul in Oceania.

In maritime Asia, another region where early modern humans were required to cross the sea to migrate, are the islands of central and southern Japan. While the large northern island, Hokkaido was partly connected with the continent, the deep Tsugaru Channel formed a sea gap between Hokkaido and Honsyu to the south. Honsyu and Kyusyu were partly connected with each other, although they were never connected to the Korean peninsula during glacial periods and a gap of at least 50 km remained. The chronology from over 100 sites in Honsyu Island now dates back to around 40 ka [17]. The southern part of Japan is mainly composed of the Ryukyu Islands. Most of the islands in Ryukyu were 100-200 km away from each other and the early traces of AMH are currently dated to around 30 ka. Such archeological data tentatively show that the early sea crossings of 50 km distance by *Homo sapiens* to the Japanese Islands could be as old as 40 ka, while the migration into the remote islands in Ryukyu Islands by sea crossing with 100-200 km distance commenced around 30 ka [18].

Although the early AMH migrations to Wallacea and Sahul could be slightly older than the migration to the Japanese Islands, both cases demonstrate new abilities and skills of AMH or *Homo sapiens* to colonize different island sizes and environments in maritime Asian regions. Based on such understanding, this paper firstly summarizes (1) possible early migration routes and dates as well as their lithic and resource use into Wallacea by AMH, then (2) reports some latest archeological cases by our archeological investigations in Wallacea and (3) discusses possible AMH island adaptations and migration strategies in Wallacea during the Pleistocene with comparative view of other island regions in the world.

### **2. Human migration and dispersal into Wallacea and Oceania**

When following the current archeological traces, only modern humans had reached Sahul and Oceania by sea crossing via Wallacea. There are some evidences of earlier human species in Luzon, Sulawesi and Flores in Wallacea [5, 8, 19] but there are no traces of early humans before *Homo sapiens* in other islands so far. The possible traces of early human species, including *Homo floresiensis*, indicate that *Homo sapiens* was not the first species to reach Wallacea, though all other evidences tentatively indicate that it was only *Homo sapiens* who colonized most of Wallacea, including its remote and small-sized islands. From this understanding, one of the most significant topics for the early modern human migration into Wallacea and Sahul is to investigate the maritime technology and capacity to adapt to changing environments that enabled early *Homo sapiens* to colonize islands in Wallacea and Sahul.

For early human migration from Wallacea into Sahul, there are basically two major routes that have been suggested as "northern" routes from Sulawesi to

Palawan and East Indonesian islands including Timor Island - divided into Indonesian West Timor and independent East Timor (or Timor Leste). Currently, the oldest possible traces of AMH in Wallacea appear in several sites in Timor around 44 ka and 42 ka [2, 3], as well as rock art dated to as early as 44 ka on the basis of

*Major Pleistocene sites in and around Wallacea Archipelago with Wallace Line. Image reproduced from the*

In Flores Island, Liang Bua provides a long sequence of human presence over 90 ka, though the site was originally occupied and used by a small-bodied species known as *Homo floresiensis* [5, 6], who was possibly related to the *Homo erectus* group, and their early migration could have been before 840 ka by crossing at least 19 km distance of sea gap. Although the upper layers of Liang Bua provide evidence of modern human occupation, the exact date of boundary between modern humans and *Homo floresiensis* is yet unclear and estimated to be around 50 ka by the excavation team [7]. Similarly, in the Philippines the presence of fossils attributed to a small-bodied hominin dubbed "*Homo luzonensis*" was found in Callao Cave, Northern Luzon, and dated to c. 67-50 ka [8]. Currently, the earliest evidence for the appearance of modern humans in the Philippine islands east of the Wallace-Huxley line comes from several AMS 14C-dates ranging between 28 and 35 ka cal. BP that were retrieved from shell midden deposits at Bubog 1, a rockshelter on Ilin Island in Mindoro Occidental [9]. An earlier human presence is indicated by cultural and

uranium-series dates of overlying speleothems in South Sulawesi [4].

*Pleistocene Archaeology - Migration,Technology, and Adaptation*

**Figure 1.**

**86**

*GEBCO world map 2014, www.gebco.net.*

faunal remains in deposits underneath the radiocarbon-dated layers.

On the Sundaic part of the Philippines, Tabon Cave in Palawan Island has delivered ancient fossil remains of modern humans, and several U-series directly date them to an age as early as c. 47 ka [10]. However, the dates' high standard errors raise doubts on their reliability. Probably more accurate are recent AMS dates Maluku Islands into the region of New Guinea and "southern" routes leading into northern Australia [20]. Along the southern routes, the previous archeological studies have been conducted in the islands of Flores, Alor, and Timor (mainly in Timor-Leste), and have so far discovered some early sites occupied by modern humans dating back to 44 and 42 ka [2, 21, 22]. The appearance of *Homo sapiens* at Liang Bua site in Flores Island (see **Figure 1**) could be as old as 50-48 ka [7], though there is no clear evidence of modern humans by this age yet. Since the site was occupied by *Homo floresiensis*, we need more solid data to confirm when this early human species disappeared or was replaced by modern humans in Flores. On the other hand, Asitau Kuru, formerly named Jerimalai Cave, located along the eastern coast of East Timor (**Figure 1**) is one the oldest prehistoric sites left by modern humans and is dated to 42-38 ka [3]. There is no direct fossil evidence of modern humans in Asitau Kuru, though the site produced the oldest evidence of pelagic fish exploitation from 42 to 38 ka and the oldest shell-made fishhooks dated to 23-16 ka [21, 23], thus the site is believed to have been used by modern humans.

The dates of the Sulawesi rock paintings are also contemporary with some of the early modern human sites in Timor including Asitau Kuru, thus the appearance of modern humans could be as old as 44-42 ka in Wallacea, along both the northern and southern routes. Considering inter-visibility between islands, however, the northern route would have provided an easier path for early modern humans to reach Sahul [34]. On the other hand, by use of coastal-viewshed analysis and ocean drift modeling, Bird and colleagues propose that the probability of randomly reaching Sahul by any route is <5% until ≥40 adults are "washed off" an island at least once every 20 years [35]. Thus, they conclude that early migration by modern humans to Sahul could have been done by intentional voyage rather than by unintentional drifting [35]. If based on such understanding, the early modern humans who crossed into Wallacea might have developed their island and maritime adaptation before their first migration into Sahul, possibly by 50-45 ka, as well as after the initial migration, during the late Pleistocene from 45 to 12 ka. As described above, there are no archeological sites attributed to early modern humans older than 45 ka in Wallacea yet. We mainly report on some major Pleistocene modern human sites in Wallacea between 35 and 12 ka and compare these with other early dated sites to characterize the lithic technology and discuss the use and exploitation of available resources.

*Island Migration, Resource Use, and Lithic Technology by Anatomically Modern…*

*DOI: http://dx.doi.org/10.5772/intechopen.93819*

**3. Resources use and lithic technology in Wallacea**

result of drifting or other unintentional voyage.

**Talaud Islands**

**89**

**3.1 Case 1: Archeological evidences from Leang Sarru Rockshelter,**

Leang Sarru is a limestone rock shelter located along the eastern coast of Salibabu, part of the Talaud Islands (**Figure 1**). The site is situated in an uplifted coral limestone block about 15 m above sea level and about 400 m inland from the current coast of Salibabu. The Talaud Islands have been located over 100 km away from their neighboring islands since the late Pleistocene, thus the modern humans undertook sea crossings of over 100 km to reach the Leang Sarru site. It is uncertain, however, if the early people reached the islands by intentional voyage or just as a

The site was first excavated by Tanudirjo [30, 31] who in 1995 opened two 1 1 m<sup>2</sup> test-pits (B2 and C2) and excavated in 10 cm spits to a depth of about 80–90 cm below ground surface. He identified four sedimentary layers with thousands of chert lithics and shell remains. Later, Ono and *Balai Arkeologi Manado* (Institute for Archeological Research in Manado) re-excavated the site opening 6 m<sup>2</sup> of 1 1 m grids (D2, D3, C3, C4, C5, C6) in 2004 [28, 29, 32]. This excavation revealed three cultural layers (corresponding to Tanudirjo's Layers 1 to 3) before reaching a hard, calcareous deposit (possibly corresponding to Tanudirjo's Layer 4). Thousands of lithic and shell remains were retrieved during the excavation, but no mammal and fish bones were found, similar to the previous excavation by Tanudirjo [30, 31]. The lack of mammal bones possibly indicates that edible animals were scarce in the Talaud Islands. In fact, the Talaud Islands in modern times have no land mammals other than about 14 species of bat, 5 species of rat, 4 species of flying fox (*Pteropus*

spp.), and 2 species of cuscus (*Ailurops ursinus* and *Strigocuscus celebensis*). The 14C dates on marine shell indicate that Layers 3 and 4 (in Tanudirjo's excavation) accumulated during the late Pleistocene between 35 and 32 ka and the lower part of Layer 2 accumulated during the final stage of the Last Glacial Maximum (LGM) around 21-18 ka. The upper part of Layer 2 and possibly the lower part of Layer 1 formed during the early Holocene, around 10-8 ka [28]. No 14C dates are available for the periods between 27 to 21 ka and 17 to 10 ka, thus it is possible that

Along the northern routes, on the other hand, excavations have been conducted in Talaud Islands, Sulawesi, and Northern Maluku Islands. Among them the oldest evidence for presence of AMH comes from South Sulawesi, from rock paintings at some cave sites and direct U-series dates as old as 43 ka [4, 24], with the earliest 14C dates in South Sulawesi dated to 36 ka [25]. Other sites older than 30 ka along the northern routes are Golo Cave in Gebe Island (**Figure 1**) dated to c. 36 ka [26, 27], Leang Sarru in the Talaud Islands (**Figures 1** and **2**) dated to 35 ka [28–32], and Bubog 1 in Mindoro Island (**Figure 1**) dated to >35 ka [9, 33]. None of these sites produced early modern human fossil remains, however, if the U-series dates of the rock paintings are correct, they can be considered as evidence of early modern human appearance in Sulawesi, as rock paintings are now recognized as a marker for the arrival of *Homo sapiens*.

**Figure 2.** *Plan (A) and front view (B) of Leang Sarru with excavated units (C).*

*Island Migration, Resource Use, and Lithic Technology by Anatomically Modern… DOI: http://dx.doi.org/10.5772/intechopen.93819*

The dates of the Sulawesi rock paintings are also contemporary with some of the early modern human sites in Timor including Asitau Kuru, thus the appearance of modern humans could be as old as 44-42 ka in Wallacea, along both the northern and southern routes. Considering inter-visibility between islands, however, the northern route would have provided an easier path for early modern humans to reach Sahul [34]. On the other hand, by use of coastal-viewshed analysis and ocean drift modeling, Bird and colleagues propose that the probability of randomly reaching Sahul by any route is <5% until ≥40 adults are "washed off" an island at least once every 20 years [35]. Thus, they conclude that early migration by modern humans to Sahul could have been done by intentional voyage rather than by unintentional drifting [35]. If based on such understanding, the early modern humans who crossed into Wallacea might have developed their island and maritime adaptation before their first migration into Sahul, possibly by 50-45 ka, as well as after the initial migration, during the late Pleistocene from 45 to 12 ka. As described above, there are no archeological sites attributed to early modern humans older than 45 ka in Wallacea yet. We mainly report on some major Pleistocene modern human sites in Wallacea between 35 and 12 ka and compare these with other early dated sites to characterize the lithic technology and discuss the use and exploitation of available resources.

### **3. Resources use and lithic technology in Wallacea**
