Neurocranium versus Face: A Morphometric Approach with Classical Anthropometric Variables for Characterizing Patterns of Cranial Integration in Extant Hominoids and Extinct Hominins

The relative importance of the two main cranial complexes, the neurocranium and the splanchnocranium, has been examined in the five species of extant hominoids and in a huge sample of extinct hominins using six standard craniometric variables that measure the length, width and height of each cranial module. Factor analysis and two-block partial least squares were used for establishing the major patterns of developmental and evolutionary integration between both cranial modules. The results obtained show that all extant hominoids (including the anatomically modern humans) share a conserved pattern of developmental integration, a result that agrees with previous studies. The pattern of evolutionary integration between both cranial modules in australopiths runs in parallel to developmental integration. In contrast, the pattern of evolutionary and developmental integration of the species of the genus Homo is the opposite, which is probably the consequence of distinctive selective regimes for both hominin groups.JAPC, JMJA and PP received fundings from Ministerio de Ciencia e Innovación, Gobierno de España (http://www.idi.mineco.gob.es), project CGL2011-30334, and Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía, España (http://www.juntadeandalucia.es/organismo​s/economiainnovacioncienciayempleo.html), project P11-HUM-7248 and Research Groups RNM-146 and HUM-607

Endostructural morphology in hominoid mandibular third premolars: discrete traits at the enamel-dentine junction

For access to specimens, we would like to thank Bernhard Zipfel, Lee Berger, Sifelani Jira (Evolutionary Studies Intitute, University of the Witwatersrand), Miriam Tawane (Ditsong Museum), Job Kibii (National Museums of Kenya), Metasebia Endalemaw, Yared Assefa (Ethiopian Authority for Research and Conservation of Cultural heritage), Yoel Rak, Alon Barash, Israel Hershkovitz (Sackler School of Medicine), Michel Toussaint (ASBL Archéologie Andennaise, Jean-Jacques Cleyet-Merle (Musée National de Préhistoire des Eyzies-de-Tayac), Ullrich Glasmacher (Institut für Geowissenschaften, Universität Heidelberg), Robert Asher, Hendrik Turni, Irene Mann (Museum für Naturkunde, Berlin), Jakov Radovčić (Croatian Natural History Museum), Christophe Boesch and Uta Schwarz (Max Planck Institute for Evolutionary Anthropology) and the Leipzig University Anatomical Collection (ULAC). For project support we thank Zeresenay Alemseged and Bill Kimbel. We would also like to thank the reviewers, the associate editor and the editor for their helpful comments and guidance, as well as Ottmar Kullmer for comments on an earlier version of this manuscript. This work was funded by the Max Planck Society, and financial support for L.K.D. was provided by a Connor Family Faculty Fellowship and the Office of Research and Development at the University of Arkansa

Two interpretations of human evolution: Essentialism and Darwinism

Despite intensive studies of a large number of fossils discovered during the 20th century there is no consensus as to the interpretation of the process of hominin evolution. Some authors see as many as six genera and some 17 species, while others argue for a single lineage from Plio/Pleistocene until today. Such diversity of interpretations of the same facts indicates lack of a uniform theoretical basis underlying studies of human evolution. Debates can be resolved using basic principles of scientific inquiry - parsimony and falsification of null hypotheses. Hypothesis testing is now possible with respect to the evolution of basic hominin characteristics such as brain size, body size and the size of the dentition that have sample sizes of a few hundred individual data points each. These characters display a continuous change with time. Analyses of variance do not falsify the null hypothesis of the existence of only one species at any time - variances around regression lines on time do not differ from the variance observed in the single species of Homo sapiens - distributions of residuals are normal. Thus, splitting of the hominin lineage into coeval species can only be based on descriptive characteristics that are liable to errors of subjective judgment.Maciej Henneber