A Craniometric Perspective on the Transition to Agriculture in Europe

Abstract

Debates surrounding the nature of the Neolithic demographic transition in Europe have historically centered on two opposing models: a "demic" diffusion model whereby incoming farmers from the Near East and Anatolia effectively replaced or completely assimilated indigenous Mesolithic foraging communities, and an "indigenist" model resting on the assumption that ideas relating to agriculture and animal domestication diffused from the Near East but with little or no gene flow. The extreme versions of these dichotomous models were heavily contested primarily on the basis of archeological and modern genetic data. However, in recent years a growing acceptance has arisen of the likelihood that both processes were ongoing throughout the Neolithic transition and that a more complex, regional approach is required to fully understand the change from a foraging to a primarily agricultural mode of subsistence in Europe. Craniometric data were particularly useful for testing these more complex scenarios, as they can reliably be employed as a proxy for the genetic relationships among Mesolithic and Neolithic populations. In contrast, modern genetic data assume that modern European populations accurately reflect the genetic structure of Europe at the time of the Neolithic transition, while ancient DNA data are still not geographically or temporally detailed enough to test continent-wide processes. Here, with particular emphasis on the role of craniometric analyses, we review the current state of knowledge regarding the cultural and biological nature of the Neolithic transition in Europe. Abstract Debates surrounding the nature of the Neolithic demographic transition in Europe have historically centered on two opposing models: a "demic" diffusion model whereby incoming farmers from the Near East and Anatolia effectively replaced or completely assimilated indigenous Mesolithic foraging communities, and an "indigenist" model resting on the assumption that ideas relating to agriculture and animal domestication diffused from the Near East but with little or no gene flow. The extreme versions of these dichotomous models were heavily contested primarily on the basis of archeological and modern genetic data. However, in recent years a growing acceptance has arisen of the likelihood that both processes were ongoing throughout the Neolithic transition and that a more complex, regional approach is required to fully understand the change from a foraging to a primarily agricultural mode of subsistence in Europe. Craniometric data were particularly useful for testing these more complex scenarios, as they can reliably be employed as a proxy for the genetic relationships among Mesolithic and Neolithic populations. In contrast, modern genetic data assume that modern European populations accurately reflect the genetic structure of Europe at the time of the Neolithic transition, while ancient DNA data are still not geographically or temporally detailed enough to test continent-wide processes. Here, with particular emphasis on the role of ...

11,000 years of craniofacial and mandibular variation in Lower Nubia

“…Mesolithic Nubians tend to have lower vaults, greater alveolar prognathism, more projected glabella, and lower and wider orbits 38 . However, major shape changes described here concern the shape of the face and mandible, i.e., cranial and mandibular regions involved in the masticatory process, which is in agreement with morphological patterns found among hunter-gatherer populations from other regions 33 35 36 39 . Facial and mandibular robusticity suggests the presence of heavy chewing muscles and larger teeth, morphological characteristics expected for populations whose subsistence strategy is based on hunting-gathering 6 34 .…”

Skull and limb morphology differentially track population history and environmental factors in the transition to agriculture in Europe

“…Craniometric data have proved a useful genetic proxy for studying this population history empirically, given that the available cranial data have much higher spatial and chronological coverage than the currently available ancient DNA data from pre-and post-transition individuals [21]. Using skeletal metrics as a means of modelling past population history provides the opportunity to compare directly the populations of interest [16,[20][21][22] rather than relying on modern genetic data from living populations, which may be affected by subsequent demographic events such as empire expansions, diasporas and local extinctions [23].…”

“…Using skeletal metrics as a means of modelling past population history provides the opportunity to compare directly the populations of interest [16,[20][21][22] rather than relying on modern genetic data from living populations, which may be affected by subsequent demographic events such as empire expansions, diasporas and local extinctions [23]. Global analyses have consistently found that human cranial shape data fit a model of neutral microevolutionary expectation (i.e.…”

The structure of cranial morphological variance in Asia: Implications for the study of modern human dispersion across the planet

“…As long as the morphological distances between populations are largely the result of stochastic events, it is expected that geographic or temporal distances between series will be linearly correlated with gene flow between populations, since gene flow will be reduced over space and time through a combination of events like isolation by distance or serial founder effects. As this depends only on intrinsic factors of the sample studied (i.e., the way by which total variance is structured between and within populations), several Words, Bones, Genes, Tools: DFG Center for Advanced Studies studies have used this assumption to test dispersion scenarios among past populations (e.g., Hubbe, Neves, and Harvati 2010;Pinhasi and von Cramon-Taubadel 2012;Reyes-Centeno et al 2015;Strauss et al 2015).…”

“…For instance, there is a vast literature dealing with the reliability of using cranial morphological differences to reconstruct major aspects of human dispersion across the planet (e.g., Betti et al 2009;Carson 2006;Harvati and Weaver 2006;Hubbe, Hanihara, and Harvati 2009;Relethford 1994Relethford , 2004Roseman 2004;Smith 2009;von Cramon-Taubadel and Weaver 2009), given the importance of these data to assess the biological characteristics of populations from regions or timeframes of interest, especially in cases where access to direct genetic information is limited. This discussion has been particularly present in the last couple of decades, as the study of morphological affinities has become a central component in the study of past human mobility, playing a major role in the discussions about the human occupation of Asia (e.g., Hanihara 1996;Harvati 2009;Reyes-Centeno et al 2015), Europe (e.g., Pinhasi and von Cramon-Taubadel 2012), Australo-Melanesia (e.g., Schillaci 2008), the Americas (e.g., de Azevedo et al 2011;Strauss et al 2015;von Cramon-Taubadel et al 2017), andPolynesia (e.g., Valentin et al 2016), not to mention studies focused on smaller geographical regions. Understanding the evolutionary forces that structure the accumulation and maintenance of phenotypic differences between populations is therefore essential to build well-informed models and hypotheses that can be tested with morphological data.…”