The contribution of subsistence to global human cranial variation Marlijn L. Noback * , Katerina Harvati Paleoanthropology Section, Senckenberg Center for Human Evolution and Paleoenvironment, Eberhard Karls Universit€ at Tübingen, Rümelinstrasse 23, 72070, Tübingen, Germany article info Article history: Received 2 September 2013 Accepted 28 November 2014 Available online xxx Keywords: Diet Masticatory adaptation Partial least squares analysis Geometric morphometrics abstract Diet-related cranial variation in modern humans is well documented on a regional scale, with ample examples of cranial changes related to the agricultural transition. However, the inﬂuence of subsistence strategy on global cranial variation is less clear, having been conﬁrmed only for the mandible, and dietary effects beyond agriculture are often neglected. Here we identify global patterns of subsistence-related human cranial shape variation. We analysed a worldwide sample of 15 populations (n ¼ 255) with known subsistence strategies using 3-D landmark datasets designed to capture the shape of different units of the cranium. Results show signiﬁcant correlations between global cranial shape and diet, especially for temporalis muscle shape and general cranial shape. Importantly, the differences between populations with either a plant- or an animal-based diet are more pronounced than those between agriculturalists and hunter-gatherers, suggesting that the inﬂuence of diet as driver of cranial variation is not limited to Holocene transitions to agricultural subsistence. Dental arch shape did not correlate with subsistence pattern, possibly indicating the high plasticity of this region of the face in relation to age, disease and individual use of the dentition. Our results highlight the importance of subsistence strategy as one of the factors underlying the evolution of human geographic cranial variation. © 2015 Elsevier Ltd. All rights reserved. Introduction Modern human geographic cranial diversity is well documented (Howells, 1973; Lahr, 1996), but the mechanisms underlying it remain unclear (Lieberman, 2008). Although masticatory stress is generally accepted as a major driver of regional human cranial variation (Carlson and Van Gerven, 1977; Hylander, 1977a; Paschetta et al., 2010), the inﬂuence of subsistence on global cra- nial morphological variation is a matter of debate (Lieberman, 2011; von Cramon-Taubadel, 2011a). Regional studies comparing agriculturalists with non-agriculturalists have found that this di- etary difference affects the shape, size and positioning of the masticatory muscle attachments, mandible, zygomatic bone, neu- rocranium and the dental arch (Carlson and Van Gerven, 1977; Hylander, 1977a, 1977b; Varrela, 1992; Larsen, 1995; Gonz alez- Jos e et al., 2005; Sardi et al., 2006; Pinhasi et al., 2008; Paschetta et al., 2010). On a global scale, however, such diet-related varia- tion has only been conﬁrmed for the mandible (von Cramon- Taubadel, 2011a). This is unexpected, as modern humans inhabit many different ecosystems where the types of food available, and consequently the strains posed on the cranium during mastication, can differ signiﬁcantly. The possible inﬂuence of subsistence strategy on the pattern of global cranial variation therefore remains unclear. Studies investigating the effects of diet on modern human cra- nial variation have mainly focused on differences between agri- culturalists and hunter-gatherers. Nevertheless, dietary adaptations have been documented throughout the hominin fossil record. Diet is considered an important driver of cranial variation among early hominins (e.g., Teaford and Ungar, 2000), while the inclusion of meat in the diet likely marked an important step in human evolution (e.g., Stanford and Bunn, 2001). Among Pleisto- cene Homo, Neanderthals are often considered to have relied heavily on meat from medium and large size terrestrial mammals on the basis of both isotopic and zooarchaeological data (e.g., Hockett and Haws, 2005; Bocherens, 2009; Richards and Trinkaus, 2009; but see Henry et al., 2010), while modern humans might have had a more ﬂexible subsistence strategy (e.g., Stiner, 2001; Hockett and Haws, 2005; Richards and Trinkaus, 2009). Food types have therefore been important throughout human evolution both in terms of the strain they posed on the cranium as well as the nutritional value they added. In order to understand possible ef- fects of diet on the evolution of modern human cranial diversity it is * Corresponding author. E-mail addresses: marlijn.noback@ifu.uni-tuebingen.de (M.L. Noback), katerina. harvati@ifu.uni-tuebingen.de (K. Harvati). Contents lists available at ScienceDirect Journal of Human Evolution journal homepage: www.elsevier.com/locate/jhevol http://dx.doi.org/10.1016/j.jhevol.2014.11.005 0047-2484/© 2015 Elsevier Ltd. All rights reserved. Journal of Human Evolution xxx (2015) 1e17 Please cite this article in press as: Noback, M.L., Harvati, K., The contribution of subsistence to global human cranial variation, Journal of Human Evolution (2015), http://dx.doi.org/10.1016/j.jhevol.2014.11.005