Environmental Archaeological Pespective Dispersal Of Anatomically Modern Human And Origin Of Agriculture In Northern China

Environmental archaeology is devoted to knowing modern human's adaptation and response to environment change, helping human to avoid damage and protecting themselves, and making it as a reference for people's subsistence and development in the future by studying on the relationship between human and climate change.Two functional reactions, response or adaptation, are available when people are subject to climate change. The dispersal of Anatomically Modern Human (AMH) and Origin of Agriculture (OA) are the best cases for detecting human's reaction to climate change. Based on the Paleolithic and Neolithic archaeological findings and environmental record in Gansu and Ningxia, environmental archaeological perspectives on the two issues will show as follows:1. Dispersal of AMHA detailed review on Human fossils, Paleolithic archaeological assemblages and DNA research indicates that a great change had happened around 40 ¹⁴C kyr BP, which can't be explained by multiregion model for modern human evolution but the dispersal of "out of Africa" of modern human. A large scale field survey was carried out for the AMH fossils, route of their dispersal of AMH, and forcing factor of the dispersal in Gansu and Ningxia Hui autonomous region since 2002. Here are some preliminary findings:(1) Microlithic assemblages are revealed at Locality PY03 and Dadiwan site dated to ca. 22-21 kyr BP during Last glacial maximum (LGM). This implies that AMH ever dispersed into this region. (2) Climate record reconstructed by precise AMS radiocarbon dating, magnetic susceptibility, grain size and CaCO³at locality ZL005 shows that it is wetter before 24 kyr BP and 19-16 kyr BP, but much drier between 24 and 19 kyr BP. It is also recorded by the transition from sand marl layer to Malan Loess deposit in Pengyang localities and Paleo-soil to loess in Dadiwan site.(3) It is much complicated for Human's reaction to climate change. People may give immediate response to or gradually adapt to the climate change.a. Hunter-gatherers mobility is related to a certain kind of stone artifacts. Both Quartzite assemblages during Marine Isotope Stage 3(MIS3) and quartz assemblages in LGM may represent low mobility, but flint ones during LGM high mobility. This indicates that drier and colder climate of LGM probably leads to the higher mobility for hunter-gatherers.b. Biomass is dominated by temperature and precipitation, and the number of archaeological sites is reflected by radiocarbon dates of northern China. The abundance of bio-resources and the number of archaeological sites are negative correlated in the long scale of 50-10 kyr BP; This correlation also testfied by defining exactly cold/dry event or warm/moist event according to high-resolution climate record as stalagmite; This correlation is still right from MIS 3 to LGM, but reverse from LGM to PG (Post glacial) when we divide the whole Upper Paleoltihc Age into MIS 3(50-25kyr BP), LGM(25-15kyr BP) and PG(15-10kyr BP). The transition from MIS 3 to LGM was driven by climate change, which leads to higher mobility for hunter-gatherers when environment turn dry and cold, so we call it climate model. However, when climate ameliorates from LGM to PG, archaeolgical sites increased but the mobility of hunter-gatherers reduced, which is the same as the model of agriculture development. So it was named as agriculture model.4. The microlithic assemblages found at PY03 and Dadiwan at ca. 22-21 kyr BP is accord to climate change model, which also supported by the local style artifact change to microlithic assemblage in Shannxi and southern Shanxi. It was concluded that the dispersal of AMH into internal Chinese Loess Plateau was induced by climate change during cold and dry LGM.2. The origin of agricultureOA research in the world and northern China shows that northern China is the only one where it does not seem to unfold, in situ, from local hunter-gatherers in ten instances known worldwide in which agriculture evolved independently; Agriculture evolution from domesticated seeds is not clear deviod of systematic agriculture survey; the cause of what ever drove the change from the hunter-gathering to agriculture also need to be detected based on the detailed environmental records. So published radiocarbon dates of archaeological sites and archaeological materials in northern China was collected, a large scale survey centered on Hulu River and Xihan River drainage was carried out, and Dadiwan site was excavated scientifically since 2004 in order to answer these questions. Here are some points.1. 10-8kyr BP, 7.4-6.6kyr BP, 4.8-4.5kyr BP and 3.8-3.5kyr BP are the low value zone based on the cumulative probability of 1364 radiocarbon dates in northern China. 10-8kyr BP and 7.4-6.6kyr BP are right on the transition Paleolithic Age to Neolithic Age and Early Neolithic to Late Neolithic Age, and they both witnessed a "culture gap" in northern China. So no continuous archaeological record for origin of agriculture was ever discovered in north China.2. Agriculture survey indicates that hunter-gathering was dominated by low ubiquity of half-domesticated Panicum miliaceum during 8-7.3 kyr BP, but developed agriculture quite higher ubiquity of domesticated Panicum miliaceum after 6.4kyr BP. The replacement of hunter-gathering by Agriculture may take place on the transition from Dadiwan 1 to Late Banpo, Yangshao Culture.3. Paleosol-loess section at Dadiwan andδ¹³C of charred Panicum miliaceum and Setaria italica combine together a continuous environmental record for the research on OA. a. The first continuous archaeological record exposed at Dadiwan site make it possible to detect the climate change for origin of early agriculture and the transition from Paleolithic to Neolithic age in northern China. Environment proxies reconstructed by magnetic susceptibility and CaCo3 suggest that 60-25kyr BP and 12-7kyr BP are moister, but 25-12kyr BP and 7.2-6.4kyr BP much drier. 7.2-6.4kyr BP is much important for OA.b.δ¹3c of charred Setaria italica goes up from Late Banpo to Changshan culture, and then it goes down until Qiaochun type and Dongzhou. It suggests that the precipitation increased continuously from Late Banpo to Changshan culture, then reduced since Changshan and reached the lowest point during Dongzhou.4. The origin of agriculture is, in essence, not to find the earliest domesticated plant seed, but to study on how, when, why the transition from hunter-gathering to agriculture happened. The following points may be related to this transition:a. Domesticated plant seed evolved into crop.b. Toolkit change from grindingstone, stone roller, sickle to stone knifec. Seperated centre for domesticated plant seed develops into agriculture centre.d. Moblie hunter-gatherering turns into sedentism.5. When, where and why did agriculture originate in northern China?a. Setaria italica and Panicum miliaceum may originate at different region, central China and transitional zone from grassland to forest, respectively.b. Agriculture may originate firstly around 8 kyr BP induced by 8.2 kyr BP event, or around 7 kyr BP triggered by 7.2-6.4 drought event.c. It has different time, different development stage and different model for the origin of agriculture in northern China.