Friday 5 August 2022

The first Neolithic farmers on Luzon Island, the Philippines.

The island of Taiwan, 125 km from the southeast coast of China, is thought to be the first island to the south of China to have been settled by Neolithic farmers, with the Dabenkeng Culture appearing here between 5500 and 5000 years before the present. Taiwan is also thought to have been the origin point of the first Neolithic settlers to arrive in the northern Philippines, more than 4000 years ago. Work on ancient DNA from archaeological sites on Luzon, the Mariana Islands, and the islands of the southwest Pacific has concluded that much of the genetic heritage of the non-Melanesian peoples of the islands of Southeast Asia and the Pacific Islands derives from an ancient migration from China via Taiwan and the Philippines.

All of this makes Luzon Island, the first major landmass likely to have been reached by Neolithic sailors heading south from Taiwan, likely to have been an important staging post in this migration, quite possibly the place in which many important cultural developments occurred. The Austronesian language family, for example, has two major divisions, one including the indigenous Formosan language of Taiwan, the other all the other significant languages of the Malay-Polynesian world, from the Philippines to Madagascar to Rapa Nui (Easter Island). The Proto-Austronesian language from which all these languages are descended is thought to have originated somewhere in the northern Philippines, probably Luzon or the Batanes Islands, or possibly on eastern Taiwan.

Northern Luzon Island is also likely to have been the first place were migrating proto-Malayo-Polynesians would have encountered people different from themselves. This island had long before been settled by the Melanesian Negrito people of the Philippines, who lived as hunter-gatherers on the island prior to the arrival of Neolithic settlers with domestic Dogs and Pigs, and a culture built around Rice-farming, between about 4200 and 4000 years ago. 

The Cagayan Valley on northern Luzon Island is the longest and widest river valley in the Philippines, with a broad alluvial plain extensively settled by Rice farmers. However, the area is still home to populations of Negrito foragers, particularly in the Sierra Madre hills to the east of the river. These people can be shown to be genetically related to the earliest, pre-Neolithic settlers in the region, though many parts of their culture are clearly more recent, including speaking a Malayo-Polynesian language and living only in remote forested areas unsuitable for Rice farming.

During the past two decades the Cagayan Valley has become a centre of great interest to archaeologists, with the uncovering of a series of shell middens which cover much of the history of settlement on the island, including the transition from a strictly foraging culture to one based around farming with foraging occurring as a supplementary activity.

In a paper published in the journal Antiquity on 1 June 2022, Hsiao-chun Hung of the Department of Archaeology and Natural History at the Australian National UniversityCheng-hwa Tsang of the Institute of Anthropology at the National Tsing Hua University, Zhenhua Deng of the Center for the Study of Chinese Archaeology and School of Archaeology and Museology at Peking University, Mary Jane Louise Bolunia and Rey Santiago of the Archaeology Division at the National Museum of the PhilippinesMike Carson of the Micronesian Area Research Center at the University of Guam, and Peter Bellwood of the School of Archaeology and Anthropology at the Australian National University, present a time-frame for the settlement of the valley based upon the radiocarbon dating of material from these shell middens, and a revised cultural and historical hypothesis based upon this.

The most westerly Pacific island chain, running from Taiwan southwards through the Philippines, has long been central in debates about the origins and early migrations of Austronesian-speaking peoples from the Asian mainland into the islands of Southeast Asia and Oceania. Hung et al. (2022).

Hung et al. identify three historical phases within the shell middens, which they term Preceramic (i.e. before the advent of ceramics), Neolithic (where ceramics have appeared), and Metal Age (where both ceramics and metal are present). The River Cagayan flows about 446 km from its headwaters in the Caraballo Mountains of central Luzon to the Babuyan Chanel where it enters the sea. The Cagayan coastal alluvial plain first formed about 7000 years ago, when rising post-glacial sealevels turned the area from a remote mountain valley into a coastal riverplain. Because Luzon is an volcanic oceanic island (albeit a rather large one), it has no surrounding continental shelf, instead rising sharply from the deep ocean. At the Last Glacial Maximum (between about 24 000 and 18 000 years ago) the sea level would have been about 120 m lower, with the Cagayan Estuary extending inwards about 100 km. It is quite possible that there are coastal and riverplain settlements lower down in the valley, but these would now be submerged and covered by metres of sediment.

(1) The Cagayan River in the Lal-Lo area; (2) part of the Magapit shell midden; (3) archaeological excavation of square P15 at Nagsabaran; (4) the Nagsabaran site, viewed from a distance. Hsiao-chun Hung in Hung et al. (2022).

The first shell midden in the Cagayan Valley was discovered at Magapit in 1971. Since this time a further 30 such shell middens have been discovered in the area, the densest concentration of shell middens anywhere in Island Southeast Asia, a reflection of the abundant shellfish available in the area in the Middle Holocene.

Most of these sites are located along a 30 km stretch of the valley between the cities of Gattaran and Lal-lo. To the north of Lal-lo the alluvium is to young to contain Neolithic sites. All of the Neolithic shell middens have been located either because they were exposed by the river cutting into them, or because they formed distinct, visible mounds. The middens are made up predominantly of shells of the Kabibe Clam, Batissa childreni, with smaller numbers of other Molluscs present, including the freshwater Snails Thiara rudisThiara winteri, Melanoides tuberculata, Melanoides granifera, and Melanoides maculata, the freshwater Clam Corbicula fluminea and the marine Clam Nitidotellina minuta. The largest shell middens are more than 5 m deep, and many overlie layers containing pottery or other Neolithic artifacts.

As well as the shell middens, there are a number of other archaeological sites in the region, particularly in the limestone hills to the east. These include deposits which run from the Preceramic to Metal Age periods, including evidence of interactions between foraging and farming communities. The largest of these sites is at Callao Cave, and includes remains attributed the Hominin Homo luzenonsis, which lived in the area more than 50 000 years ago.

The shell middens contain layers covering time intervals from the Preceramic to the Metal age, although no midden covers the whole of this period. The Gaerlan Midden, on the east side of the river 45 km upstream of its mouth, contains Preceramic and Neolithic layers, the latter containing potsherds, while the Lal-lo, Catugan, Irigayen, and Nagsabaran middens contain Neolithic and Metal Age layers, with the Neolithic layer, including red-slipped and incised pottery, extends downwards beyond the shell middens.

While none of the middens record the full 7000 years of occupation in the valley, some of the other archaeological sites might. For example the Pintú Rockshelter, 250 km to the south of Lal-lo, has a sequence of core-and-flake stone tools which appear to span the whole sequence, with pottery fragments in the middle and upper layers. Tadiocarbon dates obtained from the Pintú Rockshelter give dates from the Preceramic layers, of roughly 4960-3683 years ago, while layers containing 'reddish-orange ware' with stamped circles on the interior of the rims, similar to that found in the Cagayan Valley, appear between 4100 and 2949 years ago.

The oldest, Preceramic, shell midden layers are found at four sites, Ulet, Leodivico Capiña, Miguel Supnet and Gaerlan. These sites would have been close to a broader Cagayan Estuary between 7000 and 4200 (the estuary has moved northwards since this time as more sediment has been washed down the river and deposited). 

The oldest site, at Ulet, has yielded stone flakes but no pottery from a layer dated to between 6745 and 6495 years before the present. The Gaerlan site has a lower layer from which chert and andesite flakes have been recovered, which has been dated to 4295-4090 years before the present, overlain by a younger layer with red-slipped pottery fragments, dated to 4092-3687 years before the present.

The major archaeological sites and landscape changes through time in the lower Cagayan Valley: (1) Ulet; (2) Leodivico Capiña; (3) Callao Cave; (4) Musang Cave; (5) Arku Cave; (6) Miguel Supnet; (7) Gaerlan; (8) Nagsabaran; (9) Irigayen; (10) Magapit; (11) Pamittan; (12) Andarayan. Mike Carson in Hung et al. (2022).

The Leodivico Capiña and Miguel Supnet sites are 1.5 and 3 m deep shell middens on the west bank of the river which have yielded chert flakes and bones attributed to Wild Pigs, Deer, Rats, Birds, Turtles, and Fish, and Plant remains including nuts and tubers, but no evidence for cereals. When first discovered in the 1990s these sites were interpreted as Neolithic, due to the large amounts of pottery found in the topsoil above the middens, but neither has produced any pottery or other material associated with the Philippines Neolithic from the midden layers, and the sites are now considered to be Preceramic. Dates produced from material from the midden layers range from 7074 to 4514 years before the present.

Shell middens dating from over 7000 years ago to about 4500 years ago have been found in Vietnam, Thailand, Peninsula Malaysia, Sumatra, Sulawesi, Mindanao, and southern China. Many of these are associated with the skeletal remains of people thought to be of Melanesian affinities, and some sites in southern China and Vietnam have also included pottery. However, none of the Cagayan Valley sites of this age have produced either pottery or Human remains.

The location of the study area (lower Cagayan Valley, North Luzon), and the locations of representative (pre-farming) shell middens in southern China and Southeast Asia during the Middle Holocene, roughly 7000–4500 years before present. Hung et al. (2022).

The arrival of the Neolithic in the Cagayan Valley can be marked by the appearance of a complete new tool-set including pottery, baked clay spindle whorls, polished stone adzes, bark-cloth beakers, and a range of body ornaments including ear-pendants, bracelets, and beads made from shells, clay, schist, and semi-precious stones, including jade from Fegtian in eastern Taiwan. Stone tools from this period include few chert flakes, with most tools being highly polished.

Nagsabaran Metal Age Indo-Pacific glass beads (1), bronze bell-shaped ornaments (2), iron knife (3) and black pottery (4)–(12); Neolithic red-slipped pottery (13)–(14), clay spindle whorls (15)–(16), clay object (17), flaked chert (18)–(19), polished andesite adze (20), tuffaceous sandstone stepped-adze preform (21), green quartz schist beads (22) and Taiwan nephrite bracelet fragment (23). Scale bars are in centimetres. Hsiao-chun Hung in Hung et al. (2022).

The earliest of these sites can be dated to about 4200-4000 years before the present, with culturally similar sites of the same age also appearing in the Batanes Islands to the north. The Batanes Islands and Luzon are thought to have been settled at roughly the same time by people with a common linguistic and cultural heritage; however the two areas differ in that these were (as far as we can tell) the first people to settle the Batanes Islands, whereas the new arrivals on Luzon were entering a landscape already inhabited by an earlier, and culturally different, population.

The middens at Nagsbaran and Magapit contain layers assigned to the Neolithic contain the bones of Domestic Pigs, which have been dated to between 4448 and 4246 years before the present. These layers also contain remains of Rice, and Job's Tears (Adlay Millet or Chinese Pear Barley). Foxtail Millet is also present at Magapit - but does not appear till the Metal Age. A Rice grain from Magapit produced a radiocarbon date of 3200-3000 years before the present. Possible phytoliths (mineral grains that develop inside the leaves of a Plant) from Bananas were also found at Magapit.

Plant remains from Nagsabaran (a)–(c) and Magapit (d)–(f): (a) & (d) Rice, Oryza sativa, grains; (b) Foxtail Millet, Setaria italica, grain; (c) Job’s Tear, Coix lacryma-jobi, grain; (e) Rice spikelet base; (f) phytolith of cf. Musa sp.; item (b) is Metal Age, while all others are from Neolithic layers. Zenhua Deng in Hung et al. (2022).

Recent studies have uncovered evidence for mixed Rice and Millet agriculture during the Neolithic, from sites on the Pearl River Delta in Guangdong Province, China (dated to 4800-4600 years before the present), and Nanguanglidong in southern Taiwan (dated to more than 4500 years before the present).

The Andarayan site, which is about 80 km to the south of Magapit, has produced Neolithic red-slipped pottery from a layer which has yielded dates of 3935-3378 years before the present (from a Rice inclusion) and 3890-3060 years before the present (from a charcoal fragment). This provides three examples of Neolithic Rice production from separate sites within the Cagayan Valley, despite the alluvial plains being much smaller and less well developed at this time.

The Neolithic pottery fragments recovered from shell middens in the Cagayan Valley can be distinguished by the use of sand as a tempering agent (something added to clay to prevent pottery from cracking as it cools after baking) and the use of a red slip (a slurry added as an outer layer to form a sort of glaze). Similar pottery has been found at the Andarayan site, and at Chaolaiqiao in southeastern Taiwan, at Minanga Sipakko in West Sulawesi, and at Yinian on southeastern Hainan Island, where it has been dated to 3560-3380 years before the present. 

The presence of this distinctive pottery on Hainan is interesting, as Hainan has not previously considered to have been part of the Neolithic Austronesian expansion. The Tsat language spoken on Hainan was brought to the island by a population from northern Cham, in what is now Vietnam, fled to the island in 982 AD, following the fall of their capital to the Vietnamese. The minority Hlai people of the island speak a language called  Kra-Dai, which some linguists have suggested is related to Austronesian languages, and in particular languages from the Malayo-Polynesian branch of Austronesia, which are spoken across Island Southeast Asia. 

About 1% of the red-slipped ware from sites in the Cagayan Valley is also marked with incised and impressed decorations, and stamped geometric shapes. The most common patterns are rows of rounded or pointed impressions, intermixed with round stamps, sometimes within fields outlined with incised lines. These patterns are most common around the rims, shoulders, and feet of the vessels, where they form strait or zigzagged lines, or sometimes other geometric patterns. Some of the impressions contain traces of a white infill.

Examples of this pottery have been found in the shell middens at Gaerlan, Irigayen, Nagsabaran, and Magapit. The precise date at which such pottery appears is impossible to determine, but based upon stratigraphic extrapolation from radiocarbon dated material, Hung et al. place this somewhere between 3700 and 3500 years before the present. 

Pottery with similar patterns, including the presence of white infill material, has been found at the Neolithic sites of Man Bac and Xom Ren in Vietnam, where it has been dated to between 3900 and 3500 years before the present, although this pottery lacks the red slip seen on the pottery from Luzon and elsewhere in Island Southeast Asia. Baked clay earings of similar form have also been found in both Cagayan sites and northern Vietnam, further supporting the idea of contact between these areas in the Neolithic.

Red-slipped pottery (1)–(5), (7)–(9) & (11)–(14) and associated Rice, Oryza sativa, remains (6) & (15) phytoliths, (10) grain, from Chaolaiqiao, Nagsabaran, Yinian and Minanga Sipakko. Incised and impressed red-slipped pottery from Magapit: (16) open-mouthed pot on a pedestal, shown upside-down to reveal the stamped circles and possible fingernail impression decoration; (17) punctate-stamped sherd with lime or white clay infill in decoration; (18) sherd also displaying traces of white infill in incised lozenge motif with punctate infilling and impressed circles. Similarly decorated, red-slipped pottery from Nagsabaran (19)–(20) and Xom Ren (26)–(30) but without red slip. Baked clay earrings from Nagsabaran (21)–(25) and similar from Thach Lac (31)–(34). Hung et al. (2022).

Overlaying the Neolithic layers with red-slipped pottery at many of the Cagayan Valley sites, are later layers with black-slipped pottery. This can be achieved by firing the clay in an oxygen-deprived environment, possibly beneath Rice husks. This pottery is associated with metal objects, including iron blades and bronze ornaments, as well as monochrome glass beads. The origin of these metal objects is uncertain, but the glass beads, and similar glass beads from elsewhere in the Indo-Pacific, are thought to originate from South Asia or Mainland Southeast Asia.

Although the black-slipped and red-slipped potteries are distinct in form, the Magapit and Nagsabaran sites contain transitional layers, with both types of pottery present, suggesting that one did not suddenly displace the other. In addition, studies of DNA obtained from skeletal remains at Nagsabaran show affinities with the modern Ami people of eastern Taiwan, supporting the idea that there was a genetic continuity from the Neolithic into the metal age, despite the cultural change, although no DNA has been recovered from Neolithic skeletons in the area. 

The shell middens of the lower Cagayan Valley provide a unique archaeological resource within the Philippines, giving a more-or-less continuous record from the Preceramic hunter-gatherers of the Middle Holocene (roughly 7000 years ago), through the Neolithic and Metal Age periods into recent times; modern villagers in the area still consume shellfish and contribute to shell middens.

By the advent of the Neolithic, many of these shell middens were already covered large areas and were several metres deep. Similar shell middens are also known from other sites in South China, Vietnam, and Malaysia, but these were largely abandoned during the Neolithic, following the adoption of a Rice-farming lifestyle, whereas those in the Cagayan Valley continued to grow.

The Neolithic inhabitants of Luzon Island are known to have been highly skilled in the production and use of canoes, and to have produced a type of red-slipped pottery also found far from the island; examples have been found on Hainan Island 1000 km to the west, in the Mariana Islands, 2500 km to the east, on Sulawesi 1200 km to the south, and in the Bismark Archipelago, 3500 km to the southeast. This strongly supports the idea that, while Taiwan is still the undisputed ancestral homeland of the Austronesian language family and Malayo-Polynesian peoples, the island of Luzon, and in particular the Cagayan Valley, were very important steps in their early dispersal.

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