Search

BACKGROUND Vegetatively propagated crops are globally significant in terms of current agricultural production, as well as for understanding the long-term history of early agriculture and plant domestication. Today, significant field crops include sugarcane (Saccharum officinarum), potato (Solanum tuberosum), manioc (Manihot esculenta), bananas and plantains (Musa cvs), sweet potato (Ipomoea batatas), yams (Dioscorea spp.) and taro (Colocasia esculenta). In comparison with sexually reproduced crops, especially cereals and legumes, the domestication syndrome in vegetatively propagated field crops is poorly defined. AIMS AND SCOPE Here, a range of phenotypic traits potentially comprising a syndrome associated with early domestication of vegetatively propagated field crops is proposed, including: mode of reproduction, yield of edible portion, ease of harvesting, defensive adaptations, timing of production and plant architecture. The archaeobotanical visibility of these syndrome traits is considered with a view to the reconstruction of the geographical and historical pathways of domestication for vegetatively propagated field crops in the past. CONCLUSIONS Although convergent phenotypic traits are identified, none of them are ubiquitous and some are divergent. In contrast to cereals and legumes, several traits seem to represent varying degrees of plastic response to growth environment and practices of cultivation, as opposed to solely morphogenetic 'fixation'.

This chapter discusses the character of human activity at Niah after the transition to the Holocene, the modern climate era. The beginning of the Holocene was marked by an abrupt warming in the palaeotemperature records of the Greenland ice cap at 11,700 BP (Rasmussen et al. 2006; as in the case of Chapter 5, this is rounded here to 11,500 Br), and the end of the major climate swings which had marked the terminal stages of the Pleistocene (Rasmussen et al. 2008; Svensson et al. 2006). The geography of Southeast Asia had changed markedly in the millennia leading up to the Holocene, as the vast exposed plains of the Pleistocene Sundaland continent were progressively inundated by rising sea levels (Sathiamurthy & Voris 2006). The process continued but with complex and localized dynamics into the Holocene, relative sea levels in some parts of Southeast Asia reaching and briefly surpassing modern values by 3-5 m between about 6000 BP and 4500 BP before gradually stabilizing (Bird et al. 2006; 2010; Hanebuth et al. 2000; Horton et al. 2005; Tanabe et al. 2006; Tjia 1996; Fig. 6.1). The Mid Holocene high sea stand is taken as the approximate boundary between this chapter and the next, though it is not easily visible at Niah.