title: On the relationships of postcanine tooth size with dietary quality and brain volume in primates: implications for hominin evolution.
abstract: Brain volume and cheek-tooth size have traditionally been considered as two traits that show opposite evolutionary trends during the evolution of Homo. As a result, differences in encephalization and molarization among hominins tend to be interpreted in paleobiological grounds, because both traits were presumably linked to the dietary quality of extinct species. Here we show that there is an essential difference between the genus Homo and the living primate species, because postcanine tooth size and brain volume are related to negative allometry in primates and show an inverse relationship in Homo. However, when size effects are removed, the negative relationship between encephalization and molarization holds only for platyrrhines and the genus Homo. In addition, there is no general trend for the relationship between postcanine tooth size and dietary quality among the living primates. If size and phylogeny effects are both removed, this relationship vanishes in many taxonomic groups. As a result, the suggestion that the presence of well-developed postcanine teeth in extinct hominins should be indicative of a poor-quality diet cannot be generalized to all extant and extinct primates.
authors.affiliation: Departamento de Prehistoria y Arqueología, Facultad de Filosofía y Letras, Campus de Cartuja S/N, 18071 Granada, Spain ; Edificio Centro de Documentación Científica, Instituto Universitario de la Paz y los Conflictos, Universidad de Granada, C/Rector López Argüeta, 10871 Granada, Spain ; Anthropological Institute & Museum, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Jiménez-Arenas
authors.affiliation: Departamento de Ecología y Geología (Área de Paleontología), Facultad de Ciencias, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Pérez-Claros
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Aledo
authors.affiliation: Departamento de Ecología y Geología (Área de Paleontología), Facultad de Ciencias, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: Paul
authors.initials: P
authors.lastname: Palmqvist
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001835:Body Weight; D001921:Brain / Q000033:anatomy & histology*; D003481:Cuspid / Q000033:anatomy & histology*; D004032:Diet; D015186:Hominidae / Q000033:anatomy & histology*; D009929:Organ Size; D011323:Primates / Q000033:anatomy & histology*; D012044:Regression Analysis