Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and spread of horse domestication in the Eurasian steppes by fitting a spatially explicit stepping-stone model to genotype data from >300 horses sampled across northern Eurasia. We find strong evidence for an expansion of E. ferus out of eastern Eurasia about 160 kya, likely reflecting the colonization of Eurasia by this species. Our best-fitting scenario further suggests that horse domestication originated in the western part of the Eurasian steppe and that domestic herds were repeatedly restocked with local wild horses as they spread out of this area. By showing that horse domestication was initiated in the western Eurasian steppe and that the spread of domestic herds across Eurasia involved extensive introgression from the wild, the scenario of horse domestication proposed here unites evidence from archaeology, mitochondrial DNA, and Y-chromosomal DNA.

As Chapter 1 described, the origins of agriculture have been debated by archaeologists for most of the discipline’s history. The topic has been a particular focus of archaeological field and laboratory research from the middle of the twentieth century onwards. The number of suggested causes that has been proposed over the years for why prehistoric foragers might have become farmers appears almost endless, with everybody joining the party including the lunatic fringe (Table 10.1)! The main course of scholarly debate, though, has been conditioned partly by changing theoretical currents in archaeological thinking and perceptions of present-day or recent foraging and farming societies (Chapter 2) and partly by the application of improved methodologies (Chapter 3). In the regional studies that form the core of this book, I have concentrated primarily on the archaeological evidence left by prehistoric foragers and farmers, in all its richness, from stones to bones to rock art to starch grains (and more besides), though I have also made reference to the contributions of the several other disciplines that have contributed to the debate, including anthropology, ecology, ethnoarchaeology, genetics, geomorphology, linguistics, and palynology (pollen analysis). The next sections briefly review the principal themes that have emerged from those studies, as the basis for some concluding reflections on whether it is possible or desirable to arrive at an overarching explanation or set of explanations for why foragers became farmers. South-West Asia has probably been the focus of more debate on discussions about the origins of agriculture than anywhere else in the world. On the present evidence what can clearly be recognized as the Eurasian system of mixed farming (the cultivation of wheat and barley and the herding of sheep and goats) seems to have developed in this region very early in the Holocene. It underpinned the dramatic development of PPNB villages in and around the ‘hilly flanks’ of the Fertile Crescent some 1,000 years into the Holocene, c.8500 BC. The parts of South-West Asia where these villages came into being were also places where wild cereals, sheep, and goats were naturally located.

One of the most basic but problematic issues in modern morphometrics is how many specimens one needs to achieve accuracy in samples. Indeed, this is one of the most regularly posed questions in introductory courses. There is no simple and certainly no absolute answer to this question. However, there are a number of techniques for exploring the effect of sampling, and our aim is to provide an example of how this might function in a simplified but informative way. Thus, using resampling methods and sensitivity analyses based on randomized subsamples, we assessed sampling error in horse teeth from several modern and fossil populations. Centroid size and shape of an upper premolar (PM2) were captured using Procrustes geometric morphometrics. Means and variances (using three different statistics for shape variance) were estimated, as well as their confidence intervals. Also, the largest population sample was randomly split into progressively smaller subsamples to assess how reducing sample size affects statistical parameters. Results indicate that mean centroid size is highly accurate; even when sample size is small, errors are generally considerably smaller than differences among populations. In contrast, mean shape estimation requires large samples of tens of specimens (ca. >20), although this requirement may be less stringent when variance in a population is very small (e.g. populations that underwent strong genetic bottlenecks). Variance in either centroid size or shape can be highly inaccurate in small samples, to the point that sampling error makes it as variable as differences among spatially and chronologically well-separated populations, including two which are highly distinctive as a consequence of strong artificial selection. Likely, centroid size and shape variance require no <15–20 specimens to achieve a reasonable degree of accuracy. Results from the simplified sensitivity analysis were largely congruent with the pattern suggested by bootstrapped confidence intervals, as well as with the observations of a previous study on African monkeys. The analyses we performed, especially the sensitivity assessment, are simple and do not require much time or computational effort; however, they do necessitate that at least one sample is large (50 or more specimens). If this type of analyses became more common in geometric morphometrics, it could provide an effective tool for the preliminarily exploration of the effect of sampling on results and therefore assist in assessing their robustness. Finally, as the use of sensitivity studies increases, the present case could form part of a set of examples that allow us to better understand and estimate what a desirable sample size might be, depending on the scientific question, type of data and taxonomic level under investigation

The paper describes the initial results from renewed investigations at Niah Cave in Sarawak on the island of Borneo, famous for the discovery in 1958 of the c. 40,000-year old 'Deep Skull'. The archaeological sequences from the West Mouth and the other entrances of the cave complex investigated by Tom and Barbara Harrisson and other researchers have potential implications for three major debates regarding the prehistory of south-east Asia: the timing of initial settlement by anatomically modern humans; the means by which they subsisted in the late Pleistocene and early Holocene; and the timing, nature, and causation of the transition from foraging to farming. The new project is informing on all three debates. The critical importance of the Niah stratigraphies was commonly identified -including by Tom Harrisson himself -as because the site provided a continuous sequence of occupation over the past 40,000 years. The present project indicates that Niah was first used at least 45,000 years ago, and probably earlier; that the subsequent Pleistocene and Holocene occupations were highly variable in intensity and character; and that in some periods, perhaps of significant duration, the caves may have been more or less abandoned. The cultural sequence that is emerging from the new investigations may be more typical of cave use in tropical rainforests in south-east Asia than the Harrisson model.