G. Philip Rightmire

 
My interests include systematics, musculoskeletal anatomy, skeletal biology of human populations, paleoanthropology, and hominin evolution. My research focuses on the genus Homo, and I have been able to study fossils from many of the important prehistoric localities in Africa, western Eurasia, Java, and China. I am particularly interested in the origin and dispersal of Homo erectus at the beginning of the Pleistocene, and the ways in which this species was able to adapt to challenges posed by novel environments. Using comparative anatomical and metric evidence, I am also attempting to map the evolutionary relationships among human populations of the Middle Pleistocene. I find this work in paleoanthropology to be highly rewarding. Discoveries of fossils call for constant adjustments to our thinking about the evolutionary process, and the future promises to bring many exciting new developments.


One of my current research projects involves Dmanisi in Georgia. Since 2001, I have worked frequently at the Georgian National Museum in Tbilisi, and at the site itself. Our international team has uncovered several complete hominin skulls, vertebrae, ribs, clavicles, a fragmentary scapula, bones of the upper and lower limbs, and foot parts. A number of the specimens are in excellent condition, and at least five individuals are represented. This material has been excavated from a series of sedimentary layers that are 1.7 to 1.8 million years in age. The Dmanisi fossils constitute perhaps the most important assemblage of early Homo on record from any Plio-Pleistocene locality. In contrast to the situation at many other sites, where the remains are scattered through a substantial thickness of deposits, the Dmanisi hominins may be regarded as close contemporaries and representative of a single population (“paleodeme”). Here there is a unique opportunity to study anatomical variation within an ancient group. Such assessments help to identify traits that vary between individuals (including characters that are sexually dimorphic) and point to others that are relatively stable. The latter are more useful in species recognition and diagnosis.


Another research program centers on fossils recovered from Middle Pleistocene localities. It is recognized that the hominins from Bodo (Ethiopia), Lake Ndutu (Tanzania), Broken Hill (Zambia), and Elandsfontein (South Africa) differ from Homo erectus in brain size and other aspects of morphology. Also, there are indications that the people were capable of making relatively sophisticated stone tools, hunting large herbivores, and probably controlling fire to prepare food. However, the skulls retain numerous primitive features that set them apart from modern humans. Faces are massively built with strong supraorbital tori, frontals are flattened, and vaults remain low with less parietal expansion than is evident in Homo sapiens. The hominins from Africa are quite similar to their early Middle Pleistocene contemporaries in Europe. The spectacular assemblage of skulls and postcranial bones from Sima de los Huesos in Spain is particularly informative, and there are other important specimens from Arago Cave (France), Mauer and Steinheim (Germany), and Petralona (Greece). Considered as a whole, the evidence from Africa and Europe suggests a speciation event in which Homo erectus gave rise to a daughter lineage. At or before the beginning of the Middle Pleistocene, these new populations spread across Africa and into western Eurasia. It is possible that additional splitting occurred subsequently, as the hominins in Europe became increasingly isolated from other groups. But it is very likely that a lineage established in Africa produced the first populations resembling Homo sapiens. How the fossils from Africa and Europe should be grouped into species is currently uncertain. Other questions concern the level of morphological variation in the assemblages, character weighting and the reconstruction of phylogeny, the significance of stone artifact assemblages, and the appearance of innovative behaviors in the archaeological record.


Curriculum Vitae