Loukas Barton

Agricultural origins and the isotopic identity of domestication in northern China

Stable isotope biochemistry (δ13C and δ15N) and radiocarbon dating of ancient human and animal bone document 2 distinct phases of plant and animal domestication at the Dadiwan site in northwest China. The first was brief and nonintensive: at various times between 7900 and 7200 calendar years before present (calBP) people harvested and stored enough broomcorn millet (Panicum miliaceum) to provision themselves and their hunting dogs (Canis sp.) throughout the year. The second, much more intensive phase was in place by 5900 calBP: during this time both broomcorn and foxtail (Setaria viridis spp. italica) millets were cultivated and made significant contributions to the diets of people, dogs, and pigs (Sus sp.). The systems represented in both phases developed elsewhere: the earlier, low-intensity domestic relationship emerged with hunter–gatherers in the arid north, while the more intensive, later one evolved further east and arrived at Dadiwan with the Yangshao Neolithic. The stable isotope methodology used here is probably the best means of detecting the symbiotic human–plant–animal linkages that develop during the very earliest phases of domestication and is thus applicable to the areas where these connections first emerged and are critical to explaining how and why agriculture began in East Asia.

Current perspectives and the future of domestication studies

It is difficult to overstate the cultural and biological impacts that the domestication of plants and animals has had on our species. Fundamental questions regarding where, when, and how many times domestication took place have been of primary interest within a wide range of academic disciplines. Within the last two decades, the advent of new archaeological and genetic techniques has revolutionized our understanding of the pattern and process of domestication and agricultural origins that led to our modern way of life. In the spring of 2011, 25 scholars with a central interest in domestication representing the fields of genetics, archaeobotany, zooarchaeology, geoarchaeology, and archaeology met at the National Evolutionary Synthesis Center to discuss recent domestication research progress and identify challenges for the future. In this introduction to the resulting Special Feature, we present the state of the art in the field by discussing what is known about the spatial and temporal patterns of domestication, and controversies surrounding the speed, intentionality, and evolutionary aspects of the domestication process. We then highlight three key challenges for future research. We conclude by arguing that although recent progress has been impressive, the next decade will yield even more substantial insights not only into how domestication took place, but also when and where it did, and where and why it did not.

Patterns of East Asian pig domestication, migration, and turnover revealed by modern and ancient DNA

The establishment of agricultural economies based upon domestic animals began independently in many parts of the world and led to both increases in human population size and the migration of people carrying domestic plants and animals. The precise circumstances of the earliest phases of these events remain mysterious given their antiquity and the fact that subsequent waves of migrants have often replaced the first. Through the use of more than 1,500 modern (including 151 previously uncharacterized specimens) and 18 ancient (representing six East Asian archeological sites) pig (Sus scrofa) DNA sequences sampled across East Asia, we provide evidence for the long-term genetic continuity between modern and ancient Chinese domestic pigs. Although the Chinese case for independent pig domestication is supported by both genetic and archaeological evidence, we discuss five additional (and possibly) independent domestications of indigenous wild boar populations: one in India, three in peninsular Southeast Asia, and one off the coast of Taiwan. Collectively, we refer to these instances as “cryptic domestication,” given the current lack of corroborating archaeological evidence. In addition, we demonstrate the existence of numerous populations of genetically distinct and widespread wild boar populations that have not contributed maternal genetic material to modern domestic stocks. The overall findings provide the most complete picture yet of pig evolution and domestication in East Asia, and generate testable hypotheses regarding the development and spread of early farmers in the Far East.

Late Pleistocene climate change and Paleolithic cultural evolution in northern China: implications from the Last Glacial Maximum

Abstract Temporal and spatial patterns in archeological data from Pleistocene north China suggest strong correlations between climate change and culture change, but only in extreme cases. In these cases, climate has an immediate impact on human mobility, which is severely constrained during the pronounced cold/dry intervals of the Pleistocene. As high mobility becomes incompatible with the environmental limitations of extreme intervals, such as the Last Glacial Maximum, previously disparate mobile human groups aggregate and compete for limited and spatially segregated resources. During such times, regional cultural variation evolves in isolation and natural selection acts on group-level adaptations, facilitating the evolution of cohesive and cooperative social networks. The process of group selection further allows for the rapid diffusion of cultural and technological innovation and may explain the rapid diffusion of microblade technology throughout northeast Asia during the post-glacial period. While climate change does present challenges to human survival and may promote alternative adaptive strategies, rapid cultural evolution is driven primarily by group formation, between-group competition, and the mechanics of cultural transmission. The degree to which climate change mediates these interactions is the extent to which climate should be implicated in cultural evolution.

Particularism and the retreat from theory in the archaeology of agricultural origins.

The introduction of new analytic methods and expansion of research into previously untapped regions have greatly increased the scale and resolution of data relevant to the origins of agriculture (OA). As a result, the recognition of varied historical pathways to agriculture and the continuum of management strategies have complicated the search for general explanations for the transition to food production. In this environment, higher-level theoretical frameworks are sometimes rejected on the grounds that they force conclusions that are incompatible with real-world variability. Some of those who take this position argue instead that OA should be explained in terms of local and historically contingent factors. This retreat from theory in favor of particularism is based on the faulty beliefs that complex phenomena such as agricultural origins demand equally complex explanations and that explanation is possible in the absence of theoretically based assumptions. The same scholars who are suspicious of generalization are reluctant to embrace evolutionary approaches to human behavior on the grounds that they are ahistorical, overly simplistic, and dismissive of agency and intent. We argue that these criticisms are misplaced and explain why a coherent theory of human behavior that acknowledges its evolutionary history is essential to advancing understanding of OA. Continued progress depends on the integration of human behavior and culture into the emerging synthesis of evolutionary developmental biology that informs contemporary research into plant and animal domestication.

Storytelling and story testing in domestication

Significance Our knowledge of the domestication of animal and plant species comes from a diverse range of disciplines, and interpretation of patterns in data from these disciplines has been the dominant paradigm in domestication research. However, such interpretations are easily steered by subjective biases that typically fail to account for the inherent randomness of evolutionary processes, and which can be blind to emergent patterns in data. The testing of explicit models using computer simulations, and the availability of powerful statistical techniques to fit models to observed data, provide a scientifically robust means of addressing these problems. Here we outline the principles and argue for the merits of such approaches in the context of domestication-related questions. The domestication of plants and animals marks one of the most significant transitions in human, and indeed global, history. Traditionally, study of the domestication process was the exclusive domain of archaeologists and agricultural scientists; today it is an increasingly multidisciplinary enterprise that has come to involve the skills of evolutionary biologists and geneticists. Although the application of new information sources and methodologies has dramatically transformed our ability to study and understand domestication, it has also generated increasingly large and complex datasets, the interpretation of which is not straightforward. In particular, challenges of equifinality, evolutionary variance, and emergence of unexpected or counter-intuitive patterns all face researchers attempting to infer past processes directly from patterns in data. We argue that explicit modeling approaches, drawing upon emerging methodologies in statistics and population genetics, provide a powerful means of addressing these limitations. Modeling also offers an approach to analyzing datasets that avoids conclusions steered by implicit biases, and makes possible the formal integration of different data types. Here we outline some of the modeling approaches most relevant to current problems in domestication research, and demonstrate the ways in which simulation modeling is beginning to reshape our understanding of the domestication process.

An evaluation of competing hypotheses for the early adoption of wheat in East Asia

Abstract Recent emphasis on the recovery of plant remains from archaeological sites in East Asia permits an analysis of prehistoric cultural contact between East and West. Here we evaluate three prominent hypotheses for the introduction of wheat, a Near Eastern domesticate, to East Asia, specifically northern China. Existing evidence points to a nearly synchronous appearance of the plant, from the Inner Asian Mountains to the Yellow Sea, c. 4600–4200 years ago. Archaeological data, including the spatial distribution of directly dated wheat grains, argue against a wave of wheat-farming colonists, but point to the gradual in situ adoption of novel exotics by a diverse array of pre-existing agricultural peoples. Logic borrowed from the diffusion of innovations literature accounts for the near synchronous appearance of wheat over an enormous area, and allows for the occasional observation of anomalously older evidence without having to imagine such evidence as the origin of the diffusion.

The Transition to Agriculture at Dadiwan, People’s Republic of China

Recent excavations at the Dadiwan site in the western Loess Plateau, Gansu Province, People’s Republic of China (PRC), document the first continuous foraging-to-farming sequence in North China. The Dadiwan occupation began at about 80,000 BP and became regular by about 60,000 BP, probably before the arrival or evolution of modern Homo sapiens in North China. This record spans the transitions from nonintensive to intensive hunting and gathering and from intensive hunting and gathering to low-level Laoguantai food production and finally intensive Late Banpo, Neolithic agriculture. The intensive hunter-gatherer adaptation from which Dadiwan millet agriculture evolved did not develop at Dadiwan itself. Instead, it came south with intensive hunter-gatherer groups migrating out of the arid deserts north of the Yellow River, where the late Pleistocene–early Holocene North China Microlithic was common.

Glacial cycles and Palaeolithic adaptive variability on China's Western Loess Plateau

Intensive research on Chinas Western Loess Plateau has located 63 Palaeolithic deposits, which together allow the authors to present a general model of hominin occupation from 80 000 to 18 000 years ago. Tools, subsistence and settlement correlate nicely with the climate: the warm wet MIS3 seeing expansion and more organised acquisition of quartz, and the Late Glacial Maximum that followed, a reduction in human presence but possibly an increase in ingenuity.

Reply to Smith: On distinguishing between models, hypotheses, and theoretical frameworks

We are pleased to learn that our paper has stimulated further discussion of these important issues. However, we wish to clarify our position on several of the points mentioned in Smith’s letter (1). [↵][1]1To whom correspondence should be addressed. E-mail: gremillion.1{at}osu.edu. [1]: #xref-corresp-1-1