Ancient DNA and multimethod dating confirm the late arrival of anatomically modern humans in southern China

Abstract

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U–Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.

A multi-proxy approach to exploring Homo sapiens’ arrival, environments and adaptations in Southeast Asia

“…In the light of recent re-assessments of H. sapiens dispersal in the far East ca. 65 ka to 45 ka, although highly debated 97 , 110 , 111 , our species likely entered into south China through a similar type of rainforest, as also shown by the similarities in the isotopic data between Duoi U’Oi and Baxian 24 , 35 (Supplementary Fig. S7 ).…”

Genetic and climatic factors in the dispersal of Anatomically Modern Humans Out of Africa

“…The Neandertal admixture signal 14 has been used to trace the dispersal of the ancestors of modern populations across Eurasia and Island Southeast Asia (ISEA) as far as Australia and to date this movement to 60-50ka 12 , and potentially as late as ~53-50ka (Supplementary Information 2). This timing is concordant with a sudden proliferation of early archaeological dates reliably associated with AMH presence across Asia and Australia around 50ka 15,16 , and molecular clock dating of mitochondrial, Y chromosome, and autosomal DNA which all indicates the last common genetic ancestors of global non-African populations existed around 45-55ka 17,18 . Together, this suggests a major dispersal of AMH across Eurasia around 50-55ka and indicates that any earlier AMH movements OoA did not measurably contribute to subsequent human groups 12 .…”

Genetics and material culture support repeated expansions into Paleolithic Eurasia from a population hub out of Africa

“…Similarly, we remain oblivious about the precise location of the inferred population Hub, although North Africa or West Asia seem the most plausible candidates. More ancient genomes are needed, as well as a better understanding of the role of South and SouthEast Asia, for which currently known material culture suggests complex trajectories (Allen & O'Connell, 2014;Bird et al, 2019;Bradshaw et al, 2021;Clarkson et al, 2017;Dennell & Petraglia, 2012;Michel et al, 2016;O'Connell et al, 2018;Petraglia et al, 2010;Shackelford et al, 2018;Sun et al, 2021;Westaway et al, 2017).…”