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Froehle A.W.,Wright State University | Kellner C.M.,Northern Arizona University | Schoeninger M.J.,Wright State University | Schoeninger M.J.,University of California at San Diego | Schoeninger M.J.,Center for Academic Training and Research in Anthropogeny
American Journal of Physical Anthropology | Year: 2012

Using a sample of published archaeological data, we expand on an earlier bivariate carbon model for diet reconstruction by adding bone collagen nitrogen stable isotope values (δ15N), which provide information on trophic level and consumption of terrestrial vs. marine protein. The bivariate carbon model (δ13Capatite vs. δ 13Ccollagen) provides detailed information on the isotopic signatures of whole diet and dietary protein, but is limited in its ability to distinguish between C4 and marine protein. Here, using cluster analysis and discriminant function analysis, we generate a multivariate diet reconstruction model that incorporates δ13Capatite, δ13Ccollagen, and δ15N holistically. Inclusion of the δ15N data proves useful in resolving protein-related limitations of the bivariate carbon model, and splits the sample into five distinct dietary clusters. Two significant discriminant functions account for 98.8% of the sample variance, providing a multivariate model for diet reconstruction. Both carbon variables dominate the first function, while δ15N most strongly influences the second. Independent support for the functions' ability to accurately classify individuals according to diet comes from a small sample of experimental rats, which cluster as expected from their diets. The new model also provides a statistical basis for distinguishing between food sources with similar isotopic signatures, as in a previously analyzed archaeological population from Saipan (see Ambrose et al.: AJPA 104(1997) 343-361). Our model suggests that the Saipan islanders' 13C-enriched signal derives mainly from sugarcane, not seaweed. Further development and application of this model can similarly improve dietary reconstructions in archaeological, paleontological, and primatological contexts. Am J Phys Anthropol, 2012. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc. Source

O'Bleness M.,Aurora University | Searles V.B.,Aurora University | Varki A.,University of California at San Diego | Varki A.,Center for Academic Training and Research in Anthropogeny | And 4 more authors.
Nature Reviews Genetics | Year: 2012

Given the unprecedented tools that are now available for rapidly comparing genomes, the identification and study of genetic and genomic changes that are unique to our species have accelerated, and we are entering a golden age of human evolutionary genomics. Here we provide an overview of these efforts, highlighting important recent discoveries, examples of the different types of human-specific genomic and genetic changes identified, and salient trends, such as the localization of evolutionary adaptive changes to complex loci that are highly enriched for disease associations. Finally, we discuss the remaining challenges, such as the incomplete nature of current genome sequence assemblies and difficulties in linking human-specific genomic changes to human-specific phenotypic traits. © 2012 Macmillan Publishers Limited. All rights reserved. Source

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