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The historical lack of field-based radiographic studies of nonhuman primates within the field of anthropology is likely due to the perceived difficulty of transporting and operating X-ray equipment. Here we present a method for taking lateral cranial radiographs of nonhuman primates in the field that is simple to employ, and that produces exposed films suitable for collection of measurement data useful for growth and development studies, as well as for investigating bone and soft-tissue pathology. Several different X-ray units, film types, and portable power sources were used, all producing suitable images of similar quality, indicating that this methodology is likely not overly sensitive to these important parameters. KEY WORDS radiography; X-ray; Sulawesi macaques; roentgenographic cephalometry

The present study examines the taxonomic status of Middle Paleolithic Neanderthals by comparing their observed minimum genetic divergence from Upper Paleolithic modern humans in Europe with that observed between macaque species from Sulawesi that are known to hybridize and fully intergrade in the wild. The genetic divergence, and differentiation between Neanderthals and Upper Paleolithic modern humans, as indicated by pairwise minimum genetic distances and [F.sub.ST] values calculated from the estimated minimum genetic relationship (R) matrix derived from craniometric data, are significantly greater than those observed both between hybridizing and noninterbreeding Sulawesi macaque species, suggesting that mate recognition and the possibility of gene flow between Neanderthals and Upper Paleolithic modern humans might have been greatly reduced. These results support a species-level taxonomic distinction for the Neanderthals as suggested by proponents of the replacement model. Furthermore, assumptions regarding the monophyletic origin of modern humans from outside Europe are likely valid. Am J Phys Anthropol 115:157-166, 2001. [C] 2001 Wiley-Liss, Inc. KEY WORDS Sulawesi macaques; Neanderthals; hybridization; modern human origins; genetic distance; R matrix; [F.sub.ST]

Abstract: The present research investigates the effects of hybridization between Macaca maurus and M. tonkeana on adult male form and patterns of growth allometry. Comparisons of adult hybrid mean phenotypic values with the adult averages of the parental species indicate a condition of heterosis for cranial vault length and crown–rump length. Negative heterosis is indicated for body mass. Regression parameters describing growth allometry are generated for four craniofacial measurement variables and one body measurement using both least squares and reduced major axis regression. Comparisons of hybrid and parental regression slopes and intercepts using analysis of covariance and t-tests suggest that there is a hybrid pattern of growth allometry characterized by an increase in regression slope values coupled with lower intercept values compared to those of the parental species and the parental averages for most regression parameters. Multivariate analyses of the adult and ontogenetic morphometric data indicate significant differences across species taxa in form and shape during development and adulthood. Our finding of significant differences between hybrids and their parental taxa in growth allometry and craniofacial form and shape during development challenges the assumption often made regarding the reproductive and taxonomic significance of observed ontogenetic divergence between Neandertals and modern humans. We propose that anthropological primatology, with its goal of developing nonhuman primate models for investigating human evolution, can provide a biologically relevant means by which to empirically estimate the taxonomic significance of morphological and ontogenetic divergence observed in the hominid fossil record. [Copyright &y& Elsevier]