Modern Human Variation

Although questions of modern human origins and dispersal are subject to intense research within and outside Africa, the processes of modern human diversification during the Late Pleistocene are most often discussed within the context of recent human genetic data. This situation is due largely to the dearth of human fossil remains dating to the final Pleistocene in Africa and their almost total absence from West and Central Africa, thus limiting our perception of modern human diversification within Africa before the Holocene. Here, we present a morphometric comparative analysis of the earliest Late Pleistocene modern human remains from the Central African site of Ishango in the Democratic Republic of Congo. The early Late Stone Age layer (eLSA) of this site, dated to the Last Glacial Maximum (25e20 Ky), contains more than one hundred fragmentary human remains. The exceptional associated archaeological context suggests these remains derived from a community of hunter-fisher-gatherers exhibiting complex social and cognitive behaviors including substantial reliance on aquatic resources, development of fishing technology , possible mathematical notations and repetitive use of space, likely on a seasonal basis. Comparisons with large samples of Late Pleistocene and early Holocene modern human fossils from Africa and Eurasia show that the Ishango human remains exhibit distinctive characteristics and a higher phenotypic diversity in contrast to recent African populations. In many aspects, as is true for the inner ear conformation, these eLSA human remains have more affinities with Middle to early Late Pleistocene fossils worldwide than with extant local African populations. In addition, cross-sectional geometric properties of the long bones are consistent with archaeological evidence suggesting reduced terrestrial mobility resulting from greater investment in and use of aquatic resources. Our results on the Ishango human remains provide insights into past African modern human diversity and adaptation that are consistent with genetic theories about the deep sub-structure of Late Pleistocene African populations and their complex evolutionary history of isolation and diversification.

Estimating the biological profile from skeletal remains is an essential component of the anthropologist’s role in medico-legal investigations and in bioarchaeological analyses. Sex estimation is paramount because many methods for stature and age estimation are sex specific.
The innominate, specifically the pubic bone, is considered the best indicator of sex in adults and is widely used for sex estimation. The Klales et al. (2012) method, a modification of Phenice (1969) techniques, is currently being used and cited in forensic cases reports throughout the United States and internationally; the method is also being used in bioarchaeological contexts. In light of Daubert and the NAS (2008) report, the method needs to be tested for validity and reliability. The present research tests the reliability and validity of the method in multiple national and international samples.
A sample of adult pelves (n = 532; F = 239; M = 293) from several collections was blindly scored for the three Klales et al. (2012) traits (ventral arc, subpubic contour, and medial aspect of the ischio-pubic ramus) by an experienced observer. The samples are derived from Thailand (KKU), South Africa (PBC), and various U.S. populations (WMBDC; Arizona) Using the original logistic regression classification equations by Klales et al. (2012), the external validity of the original method was tested. Next, sample specific equations and a pooled sample logistic regression equation were generated. Results indicate that the method works well for classification (accuracy 75.9%-93.3%) and is valid; however, classification accuracy increases when using sample-specific equations (accuracy 97.9%-99%).