title: Strontium isotope evidence for landscape use by early hominins.
abstract: Ranging and residence patterns among early hominins have been indirectly inferred from morphology, stone-tool sourcing, referential models and phylogenetic models. However, the highly uncertain nature of such reconstructions limits our understanding of early hominin ecology, biology, social structure and evolution. We investigated landscape use in Australopithecus africanus and Paranthropus robustus from the Sterkfontein and Swartkrans cave sites in South Africa using strontium isotope analysis, a method that can help to identify the geological substrate on which an animal lived during tooth mineralization. Here we show that a higher proportion of small hominins than large hominins had non-local strontium isotope compositions. Given the relatively high levels of sexual dimorphism in early hominins, the smaller teeth are likely to represent female individuals, thus indicating that females were more likely than males to disperse from their natal groups. This is similar to the dispersal pattern found in chimpanzees, bonobos and many human groups, but dissimilar from that of most gorillas and other primates. The small proportion of demonstrably non-local large hominin individuals could indicate that male australopiths had relatively small home ranges, or that they preferred dolomitic landscapes.
authors.affiliation: Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany. sandi.copeland@colorado.edu
authors.forename: Sandi R
authors.initials: SR
authors.lastname: Copeland
authors.forename: Matt
authors.initials: M
authors.lastname: Sponheimer
authors.forename: Darryl J
authors.initials: DJ
authors.lastname: de Ruiter
authors.forename: Julia A
authors.initials: JA
authors.lastname: Lee-Thorp
authors.forename: Daryl
authors.initials: D
authors.lastname: Codron
authors.forename: Petrus J
authors.initials: PJ
authors.lastname: le Roux
authors.forename: Vaughan
authors.initials: V
authors.lastname: Grimes
authors.forename: Michael P
authors.initials: MP
authors.lastname: Richards
mesh_terms: D000818:Animals; D003710:Demography; D004032:Diet; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry; D015186:Hominidae / Q000502:physiology*; D008297:Male; D013019:South Africa; D021241:Spectrometry, Mass, Electrospray Ionization; D013325:Strontium Isotopes / Q000032:analysis*; D014070:Tooth / Q000737:chemistry
chemical_list: D013325:Strontium Isotopes