Long and attenuated: comparative trends in the domestication of tree fruits

This paper asks whether we can identify a recurrent domestication syndrome for tree crops (fruits, nuts) and track archaeologically the evolution of domestication of fruits from woody perennials. While archaeobotany has made major contributions to documenting the domestication process in cereals and other annual grains, long-lived perennials have received less comparative attention. Drawing on examples from across Eurasia, comparisons suggest a tendency for the larger domesticated fruits to contain seeds that are proportionally longer, thinner and with more pointed (acute to attenuated) apices. Therefore, although changes in flavour, such as increased sweetness, are not recoverable, seed metrics and shape provide an archaeological basis for tracking domestication episodes in fruits from woody perennials. Where available, metrical data suggest length increases, as well as size diversification over time, with examples drawn from the Jomon of Japan (Castanea crenata), Neolithic China (Prunus persica) and the later Neolithic of the Near East (Olea europaea, Phoenix dactylifera) to estimate rates of change. More limited data allow us to also compare Mesoamerica avocado (Persea americana) and western Pacific Canarium sp. nuts and Spondias sp. fruits. Data from modern Indian jujube (Ziziphus mauritiana) are also considered in relation to seed length:width trends in relation to fruit contents (flesh proportion, sugar content). Despite the long generation time in tree fruits, rates of change in their seeds are generally comparable to rates of phenotypic evolution in annual grain crops, suggesting that gradual evolution via unconscious selection played a key role in initial processes of tree domestication, and that this had begun in the later Neolithic once annual crops had been domesticated, in both west and east Asia

Transitions in Productivity: Rice Intensification from Domestication to Urbanisation

Archaeobotanical research in East and Southeast Asia provides evidence for transitions between lower and higher productivity forms of rice. These shifts in productivity are argued to help explain patterns in the domestication process and the rise of urban societies in these regions. The domestication process, which is now documented as having taken a few millennia, and coming to an end between 6700 and 5900 bp, involved several well documented changes, all of which served to increase the yield of rice harvests by an estimated 366 per cent; this increase provides an in-built pull factor for domestication. Once domesticated, rice diversified into higher productivity, labour-demanding wet rice and lower-yield dry rice. While wet rice in the Lower Yangtze region of China provided a basis for increasing population density and social hierarchy, it was the development of less productive and less demanding dry rice that helped to propel the migrations of farmers and the spread of rice agriculture across South China and Southeast Asia. Later intensification in Southeast Asia, a shift back to wet rice, was a necessary factor for increasing hierarchy and urbanisation in regions such as Thailand

The origins and early dispersal of horsegram (Macrotyloma uniflorum), a major crop of ancient India

Horsegram has been an important crop since the beginning of agriculture in many parts of South Asia. Despite horsegram’s beneficial properties as a hardy, multi-functional crop, it is still regarded as a food of the poor, particularly in southern India. Mistakenly regarded as a minor crop, largely due to entrenched biases against this under-utilised crop, horsegram has received far less research than other pulses of higher status. The present study provides an updated analysis of evidence for horsegram’s origins, based on archaeological evidence, historical linguistics, and herbarium collections of probable wild populations. Our survey of herbarium specimens provides an updated map of the probable range of the wild progenitor. A large database of modern reference material provides an updated baseline for distinguishing wild and domesticated seeds, while an extensive dataset of archaeological seed measurements provides evidence for regional trends towards larger seed size, indicating domestication. Separate trends towards domestication are identified for north-western India around 4000 BP, and for the Indian Peninsula around 3500 BP, suggesting at least two separate domestications. This synthesis provides a new baseline for further germplasm sampling, especially of wild populations, and further archaeobotanical data collection

Alternative strategies to agriculture: the evidence for climatic shocks and cereal declines during the British Neolithic and Bronze Age (a reply to Bishop)

Our suggestion that agriculture was temporarily abandoned for several centuries throughout much of mainland Britain after 3600 BC has provoked criticism, notably the claim by Bishop (2015) that we have missed continuity in Scotland. We demonstrate that firm evidence for widespread agriculture within the later Neolithic is still unproven. We trace the disappearance of cereals and the associated population collapse to a probable climatic shift that impacted the abundance of rainfall and lowered temperatures, thus affecting the reliability of cereals. Divergent strategies and patterns are identified on the Scottish Islands versus the mainland, which has more in common with England, Wales and Ireland. We argue that climate shocks disrupt existing subsistence patterns, to which varied responses are represented by divergent island and mainland patterns, both in the Late Neolithic and during the Early and Middle Bronze Age. Favourable climates encouraged population growth and subsistence innovation, such as at the start of the Neolithic and in the Beaker period

Seed coat thinning during horsegram (Macrotyloma uniflorum) domestication documented through synchrotron tomography of archaeological seeds

Reduction of seed dormancy mechanisms, allowing for rapid germination after planting, is a recurrent trait in domesticated plants, and can often be linked to changes in seed coat structure, in particular thinning. We report evidence for seed coat thinning between 2,000 BC and 1,200 BC, in southern Indian archaeological horsegram (Macrotyloma uniflorum), which it has been possible to document with high precision and non-destructively, through high resolution x-ray computed tomography using a synchrotron. We find that this trait underwent stepped change, from thick to semi-thin to thin seed coats, and that the rate of change was gradual. This is the first time that the rate of evolution of seed coat thinning in a legume crop has been directly documented from archaeological remains, and it contradicts previous predictions that legume domestication occurred through selection of pre-adapted low dormancy phenotypes from the wild

The spread of agriculture in eastern Asia: Archaeological bases for hypothetical farmer/language dispersals

Millets and rice were important for the demographic history of China. This review draws on current archaeobotanical evidence for rice and millets across China, Korea, eastern Russia, Taiwan, Mainland southeast Asia, and Japan, taking a critical approach to dating evidence, evidence for cultivation, and morphological domestication. There is no evidence to suggest that millets and rice were domesticated simultaneously within a single region. Instead, 5 regions of north China are candidates for independent early cultivation of millets that led to domestication, and 3 regions of the Yangtze basin are candidates for separate rice domestication trajectories. The integration of rice and millet into a single agricultural system took place ca. 4000BC, and after this the spread of agricultural systems and population growth are in evidence. The most striking evidence for agricultural dispersal and population growth took place between 3000 and 2500BC, which has implications for major language dispersals

Genetic evaluation of domestication-related traits in rice: implications for the archaeobotany of rice origins

Domestication is the process in which preferred genetic changes in wild plants and animals have been selected by humans. In other words, domesticated plants have become adapted to being part of human-managed ecosystems. Asian cultivated rice, Oryza sativa L., is one of the most important crops in the world and is known to have been domesticated from its wild ancestor, O. rufipogon. Many morphological changes in cultivated rice have been beneficial to humans in terms of increased efficiency of cultivation and yield that supported the development of human civilisations. The genetic mechanisms of these changes have been extensively studied since rice genome sequences were determined, and based on genome analyses, the origin of rice has been widely discussed. Most of the domestication-related traits and genes are, however, often evaluated based on the genetic background of cultivated rice, leading to misinterpretation of rice domestication. Here, we review several genetic changes and discuss the importance of evaluating these traits in the wild rice genetic background to understand the process of rice domestication. In this review, we also provide a phenotypic evaluation of domestication-related traits

Plants to textiles: Local bast fiber textiles at Pre-Pottery Neolithic Çatalhöyük

Textiles from Neolithic Çatalhöyük are among the earliest and best-preserved woven plant artifacts from ancient Southwest Asia. Recent examinations of textiles from Çatalhöyük's East Mound middle habitation phase (6700–6500 cal. B. C.) provide surprising evidence that instead of being made from flax (linen, Linum usitatissimum), as previously thought, the fibers are from the inner bark of trees (tree bast), some samples identified as bast from locally growing oak (Quercus sp.). The present paper reports on a separate analysis of five woven textile and two cordage fragments, also from the middle habitation phase. Our aims were to identify their raw material origins, distinguish the thread-making technology present, and to situate them within the broader chaîne opératoire of thread and textile making in the prehistory of the region. We observed that the thread-making technology was based on an end-to-end splicing method, and while agreeing with the earlier published study, that tree bast, not flax, was the source of the fiber, our results further suggest that elm (Ulmus sp.) and willow/poplar (Salicaceae) were also among the bast raw materials used in textile manufacture at the site. From these results we can infer that the textile makers possessed complex understandings of the biology, physiology, and seasonality of local wild tree genera throughout the surrounding environment