Elise Patole-Edoumba

Anatomically modern human in Southeast Asia (Laos) by 46 ka

Uncertainties surround the timing of modern human emergence and occupation in East and Southeast Asia. Although genetic and archeological data indicate a rapid migration out of Africa and into Southeast Asia by at least 60 ka, mainland Southeast Asia is notable for its absence of fossil evidence for early modern human occupation. Here we report on a modern human cranium from Tam Pa Ling, Laos, which was recovered from a secure stratigraphic context. Radiocarbon and luminescence dating of the surrounding sediments provide a minimum age of 51–46 ka, and direct U-dating of the bone indicates a maximum age of ∼63 ka. The cranium has a derived modern human morphology in features of the frontal, occipital, maxillae, and dentition. It is also differentiated from western Eurasian archaic humans in aspects of its temporal, occipital, and dental morphology. In the context of an increasingly documented archaic–modern morphological mosaic among the earliest modern humans in western Eurasia, Tam Pa Ling establishes a definitively modern population in Southeast Asia at ∼50 ka cal BP. As such, it provides the earliest skeletal evidence for fully modern humans in mainland Southeast Asia.

Early Modern Humans and Morphological Variation in Southeast Asia: Fossil Evidence from Tam Pa Ling, Laos

Little is known about the timing of modern human emergence and occupation in Eastern Eurasia. However a rapid migration out of Africa into Southeast Asia by at least 60 ka is supported by archaeological, paleogenetic and paleoanthropological data. Recent discoveries in Laos, a modern human cranium (TPL1) from Tam Pa Ling‘s cave, provided the first evidence for the presence of early modern humans in mainland Southeast Asia by 63-46 ka. In the current study, a complete human mandible representing a second individual, TPL 2, is described using discrete traits and geometric morphometrics with an emphasis on determining its population affinity. The TPL2 mandible has a chin and other discrete traits consistent with early modern humans, but it retains a robust lateral corpus and internal corporal morphology typical of archaic humans across the Old World. The mosaic morphology of TPL2 and the fully modern human morphology of TPL1 suggest that a large range of morphological variation was present in early modern human populations residing in the eastern Eurasia by MIS 3.

Early Modern Humans from Tam Pà Ling, Laos: Fossil Review and Perspectives

Despite the importance of its geographical position for early modern human migration through Australasia, the Indochinese Peninsula has produced relatively few fossils or well-documented archaeological sites, resulting in a poor chronology for early occupation. Tam Pà Ling (TPL), a cave in northern Laos, is one of the rare sites yielding fossils contemporaneous with the earliest migrants into Australasia within a securely established chronology. From its discovery in 2008 until the most recently filed season in 2016, TPL has provided evidence of a modern human presence in the region by marine isotope stages 4 and 3. A partial cranium (TPL1), two mandibles (TPL2, TPL3), and assorted postcranial fragments (TPL4, TPL5) represent the earliest well-dated, anatomically modern humans in the Indochinese Peninsula and introduce new migration routes into the area. The sedimentary context of TPL is described and refined elsewhere, resulting in an approximate age of 44–63 ka for the TPL1 and TPL2 fossils and a maximum depositional age of 70 ka for the lowest layer containing the TPL3 mandible. This is 20 ka older than the depositional ages for the TPL1 and TPL2 fossils and establishes a new upper limit for sedimentary deposition at the site and for the associated fossil evidence. In this study, we review previously presented material (TPL1–TPL3), present unpublished postcranial material (TPL4 and TPL5), and provide dental metric analysis of the TPL1–TPL3 specimens.

The prehistoric peopling of Southeast Asia

Ancient migrations in Southeast Asia The past movements and peopling of Southeast Asia have been poorly represented in ancient DNA studies (see the Perspective by Bellwood). Lipson et al. generated sequences from people inhabiting Southeast Asia from about 1700 to 4100 years ago. Screening of more than a hundred individuals from five sites yielded ancient DNA from 18 individuals. Comparisons with present-day populations suggest two waves of mixing between resident populations. The first mix was between local hunter-gatherers and incoming farmers associated with the Neolithic spreading from South China. A second event resulted in an additional pulse of genetic material from China to Southeast Asia associated with a Bronze Age migration. McColl et al. sequenced 26 ancient genomes from Southeast Asia and Japan spanning from the late Neolithic to the Iron Age. They found that present-day populations are the result of mixing among four ancient populations, including multiple waves of genetic material from more northern East Asian populations. Science, this issue p. 92, p. 88; see also p. 31 Ancient genomes reveal four layers of human migration into Southeast Asia. The human occupation history of Southeast Asia (SEA) remains heavily debated. Current evidence suggests that SEA was occupied by Hòabìnhian hunter-gatherers until ~4000 years ago, when farming economies developed and expanded, restricting foraging groups to remote habitats. Some argue that agricultural development was indigenous; others favor the “two-layer” hypothesis that posits a southward expansion of farmers giving rise to present-day Southeast Asian genetic diversity. By sequencing 26 ancient human genomes (25 from SEA, 1 Japanese Jōmon), we show that neither interpretation fits the complexity of Southeast Asian history: Both Hòabìnhian hunter-gatherers and East Asian farmers contributed to current Southeast Asian diversity, with further migrations affecting island SEA and Vietnam. Our results help resolve one of the long-standing controversies in Southeast Asian prehistory.

Modern human fossils from Tam Pa Ling, Laos

Supplement: Program of the 81st Annual Meeting of the American Association of Physical Anthropologists (2012)The catacomb of Saints Peter and Marcellinus located in the south-east of Rome approximately contains 25 000 graves dated from the 3rd to the 5th century AD. Seven newly discovered rooms having an unusual organization in the heart of the catacomb were investigated in 2003. Excavations of these rooms revealed a mass grave, where 3000 corpses were laid together. These individuals were stacked in rows apparently following a common fatal incident. Presumably, this epidemic crisis occurred between the 1st and the 3rd century AD. The specific funerary treatment (textile wrapping and plaster) recalls mummification and might be related to exogenous practices, possibly connected to Early Christians. Moreover, the presence of rare and expensive materials (e.g., Baltic amber, resins and gold threads) may indicate a high social status. Stable isotope analyses (carbon, nitrogen and oxygen) of bone collagen, bone apatite and tooth hydroxyapatite were carried out on 111 individuals to obtain further information on their diet and residential mobility. Additionally, a study of dental nonmetric traits was conducted on 200 individuals to define the biological distance between the deceased and to assess their phenetic similarity. The combination of these two approaches will bring new insight into the homogeneity of the Early population of the catacomb of Saints Peter and Marcellinus and the relationship between funerary practices and geographical origin of buried individuals.

Ancient Genomics Reveals Four Prehistoric Migration Waves into Southeast Asia

Two distinct population models have been put forward to explain present-day human diversity in Southeast Asia. The first model proposes long-term continuity (Regional Continuity model) while the other suggests two waves of dispersal (Two Layer model). Here, we use whole-genome capture in combination with shotgun sequencing to generate 25 ancient human genome sequences from mainland and island Southeast Asia, and directly test the two competing hypotheses. We find that early genomes from Hoabinhian hunter-gatherer contexts in Laos and Malaysia have genetic affinities with the Onge hunter-gatherers from the Andaman Islands, while Southeast Asian Neolithic farmers have a distinct East Asian genomic ancestry related to present-day Austroasiatic-speaking populations. We also identify two further migratory events, consistent with the expansion of speakers of Austronesian languages into Island Southeast Asia ca. 4 kya, and the expansion by East Asians into northern Vietnam ca. 2 kya. These findings support the Two Layer model for the early peopling of Southeast Asia and highlight the complexities of dispersal patterns from East Asia.