American Journal of Physical Anthropology

Buzon, Michele R.; Simonetti, Antonio

doi: 10.1002/ajpa.22235pmid: 23440634

As a successful technique for identifying residential mobility in other areas, this study investigates the feasibility of using 87Sr/86Sr analysis to track the movements of the ancient peoples of Egypt and Nubia in the Nile Valley, who interacted via trade, warfare, and political occupations over millennia. Dental enamel from faunal remains is used to examine variability in strontium sources in seven regional sites; human enamel samples are analyzed from eight Nile Valley sites in order to trace human movements. The faunal samples show a wide range of 87Sr/86Sr values demonstrating that some animals were raised in a variety of locales. The results of the human samples reveal overlap in 87Sr/86Sr values between Egyptian and Nubian sites; however, Egyptian 87Sr/86Sr values (mean/median [0.70777], sd [0.00027]) are statistically higher than the Nubian 87Sr/86Sr values (mean [0.70762], median [0.70757], sd [0.00036], suggesting that it is possible to identify if immigrant Egyptians were present at Nubian sites. Samples examined from the site of Tombos provide important information regarding the sociopolitical activities during the New Kingdom and Napatan periods. Based on a newly established local 87Sr/86Sr range, human values, and bioarchaeological evidence, this study confirms the preliminary idea that immigrants, likely from Egypt, were present during the Egyptian New Kingdom occupation of Nubia. In the subsequent Napatan period when Nubia ruled Egypt as the 25th Dynasty, 87Sr/86Sr values are statistically different from the New Kingdom component and indicate that only locals were present at Tombos during this developmental time. Am J Phys Anthropol 151:1–9, 2013. © 2013 Wiley Periodicals, Inc.

Bučková, Jana; Černý, Viktor; Novelletto, Andrea

doi: 10.1002/ajpa.22236pmid: 23460272

The African Sahel is conducive to studies of divergence/admixture genetic events as a result of its population history being so closely related with past climatic changes. Today, it is a place of the co‐existence of two differing food‐producing subsistence systems, i.e., that of sedentary farmers and nomadic pastoralists, whose populations have likely been formed from several dispersed indigenous hunter‐gatherer groups. Using new methodology, we show here that the male gene pool of the extant populations of the African Sahel harbors signatures of multiple and differentiated contributions from different genetic sources. We also show that even if the Fulani pastoralists and their neighboring farmers share high frequencies of four Y chromosome subhaplogroups of E, they have drawn on molecularly differentiated subgroups at different times. These findings, based on combinations of SNP and STR polymorphisms, add to our previous knowledge and highlight the role of differences in the demographic history and displacements of the Sahelian populations as a major factor in the segregation of the Y chromosome lineages in Africa. Interestingly, within the Fulani pastoralist population as a whole, a differentiation of the groups from Niger is characterized by their high presence of R1b‐M343 and E1b1b1‐M35. Moreover, the R1b‐M343 is represented in our dataset exclusively in the Fulani group and our analyses infer a north‐to‐south African migration route during a recent past. Am J Phys Anthropol 151:10–21, 2013. © 2013 Wiley Periodicals, Inc.

Turner, Bethany L.; Klaus, Haagen D.; Livengood, Sarah V.; Brown, Leslie E.; Saldaña, Fausto; Wester, Carlos

doi: 10.1002/ajpa.22238pmid: 23440681

This study investigates two key variables—residential context and subsistence—among sacrificial victims dating to the Late Horizon (A.D. 1450–1532) in the Huaca de los Sacrificios at the Chotuna‐Chornancap Archaeological Complex in north coastal Peru. We investigate whether aspects of sacrifice in this distant coastal province mirrored that found in Inca heartland contexts such as the capacocha, or remained more typical of coastal sacrificial traditions. Stable carbon, nitrogen, and oxygen isotope values were characterized in bone carbonate, bone collagen, and hair keratin to estimate geographic residence during the decade before death and diet in the decade, versus months, before death. Bone δ18Ocarbonate values have a mean (±SD) of 26.8 ± 1.1%, bone δ13Ccarbonate values −6.7 ± 1.7%, and bone δ13Ccollagen values 11.8 ± 1.3%; bone δ15Ncollagen values have a mean of 11.5 ± 1.3%. Combined hair δ13Ckeratin values have a mean of −12.8 ± 1.6%, and hair δ15Nkeratin values 10.8 ± 1.3%. In contrast to contemporaneous coastal and highland contexts, we are unable to identify immigrants among the sacrificed individuals or changes in diet that indicate provisioning with a standardized diet leading up to death. Instead, results suggest that victims were local to the area, but consumed moderately variable diets consistent with local subsistence patterns. These findings suggest a distinct pattern of human sacrifice in the Late Horizon and underscore the regional and temporal variation in sacrificial practices in the central Andes. Am J Phys Anthropol 151:22–37, 2013. © 2013 Wiley Periodicals, Inc.

Balzeau, Antoine; Rougier, Hélène

doi: 10.1002/ajpa.22249pmid: 23460369

The question of whether suprainiac depressions observed on Neandertals and in other human samples are homologous is widely discussed. Recently (Balzeau and Rougier, 2010), we ascertained the autapomorphic status of the Neandertal suprainiac fossa as a depression showing specific external bone features together with a thinning of the diploic layer with no substantial remodeling nor variation in the external table thickness. A suprainiac fossa with these characteristics is systematically present on Neandertals from the earliest developmental stages on, and since the beginning of the differentiation of the Neandertal lineage. Here, we present a detailed analysis of the micro‐CT dataset (resolution of 50 μm) of the occipital bone of the La Ferrassie 8 Neandertal child, whose proposed age‐at‐death is around 2 years, and we compare it to the adult condition as represented by La Chapelle‐aux‐Saints 1 (resolution of 122 μm). We describe and quantify the boundaries between the different structural layers of the occipital bone, namely the external and internal tables and the diploic layer. We also describe very fine details of the diploic layer structure that had never before been observed on fossil hominins. This study illustrates for the first time that the internal particularities that make the suprainiac fossa a Neandertal autapomorphy are evident early during growth and development. Moreover, we demonstrate that the developmental pattern and causes of expression for the features observed in modern humans and Neandertals are certainly different, indicating that these features are not homologous traits from evolutionary and functional perspectives. Consequently, we confirm the autapomorphic status of the Neandertal suprainiac fossa. Am J Phys Anthropol 151:38–48, 2013. © 2013 Wiley Periodicals, Inc.

Starbuck, John M.; Cole, Theodore M.; Reeves, Roger H.; Richtsmeier, Joan T.

doi: 10.1002/ajpa.22255pmid: 23505010

The most common live‐born human aneuploidy is trisomy 21, which causes Down syndrome (DS). Dosage imbalance of genes on chromosome 21 (Hsa21) affects complex gene‐regulatory interactions and alters development to produce a wide range of phenotypes, including characteristic facial dysmorphology. Little is known about how trisomy 21 alters craniofacial morphogenesis to create this characteristic appearance. Proponents of the "amplified developmental instability" hypothesis argue that trisomy 21 causes a generalized genetic imbalance that disrupts evolutionarily conserved developmental pathways by decreasing developmental homeostasis and precision throughout development. Based on this model, we test the hypothesis that DS faces exhibit increased developmental instability relative to euploid individuals. Developmental instability was assessed by a statistical analysis of fluctuating asymmetry. We compared the magnitude and patterns of fluctuating asymmetry among siblings using three‐dimensional coordinate locations of 20 anatomic landmarks collected from facial surface reconstructions in four age‐matched samples ranging from 4 to 12 years: 1) DS individuals (n = 55); 2) biological siblings of DS individuals (n = 55); 3) and 4) two samples of typically developing individuals (n = 55 for each sample), who are euploid siblings and age‐matched to the DS individuals and their euploid siblings (samples 1 and 2). Identification in the DS sample of facial prominences exhibiting increased fluctuating asymmetry during facial morphogenesis provides evidence for increased developmental instability in DS faces. We found the highest developmental instability in facial structures derived from the mandibular prominence and lowest in facial regions derived from the frontal prominence. Am J Phys Anthropol 151:49–57, 2013. © 2013 Wiley Periodicals, Inc.

Pijpe, Jeroen; Voogt, Alex; Oven, Mannis; Henneman, Peter; Gaag, Kristiaan J.; Kayser, Manfred; Knijff, Peter

doi: 10.1002/ajpa.22256pmid: 23526367

The Maldives are an 850 km‐long string of atolls located centrally in the northern Indian Ocean basin. Because of this geographic situation, the present‐day Maldivian population has potential for uncovering genetic signatures of historic migration events in the region. We therefore studied autosomal DNA‐, mitochondrial DNA‐, and Y‐chromosomal DNA markers in a representative sample of 141 unrelated Maldivians, with 119 from six major settlements. We found a total of 63 different mtDNA haplotypes that could be allocated to 29 mtDNA haplogroups, mostly within the M, R, and U clades. We found 66 different Y‐STR haplotypes in 10 Y‐chromosome haplogroups, predominantly H1, J2, L, R1a1a, and R2. Parental admixture analysis for mtDNA‐ and Y‐haplogroup data indicates a strong genetic link between the Maldive Islands and mainland South Asia, and excludes significant gene flow from Southeast Asia. Paternal admixture from West Asia is detected, but cannot be distinguished from admixture from South Asia. Maternal admixture from West Asia is excluded. Within the Maldives, we find a subtle genetic substructure in all marker systems that is not directly related to geographic distance or linguistic dialect. We found reduced Y‐STR diversity and reduced male‐mediated gene flow between atolls, suggesting independent male founder effects for each atoll. Detected reduced female‐mediated gene flow between atolls confirms a Maldives‐specific history of matrilocality. In conclusion, our new genetic data agree with the commonly reported Maldivian ancestry in South Asia, but furthermore suggest multiple, independent immigration events and asymmetrical migration of females and males across the archipelago. Am J Phys Anthropol 151:58–67, 2013. © 2013 Wiley Periodicals, Inc.

Hruschka, Daniel J.; Rush, Elaine C.; Brewis, Alexandra A.

doi: 10.1002/ajpa.22258pmid: 23553559

The study of human variation in adiposity and lean mass is important for understanding core processes in human evolution, and is increasingly a public health concern as the “obesity epidemic” expands globally. The dominant measure of population differences in adiposity is Body Mass Index (BMI), which suffers from systematic biases across populations due to variation in the relationship between true body fat, height and weight. Here we develop simplified corrections for such anthropometric‐based measures of adiposity that can take into account this population variation. These corrections derive from a recent model proposed by Burton that assumes humans accrue mass in two ways—growth in height that adds bone and muscle, and growth in body fat and the ancillary fat‐free mass (FFM) needed to support this additional body fat. We analyze two ethnically diverse datasets with dual X‐ray absorptiometry‐measured (DXA) fat mass, assessing the fit of Burton's model and deriving novel corrections based on estimated musculoskeletal slenderness. The resulting model provides excellent fit to fat mass within populations (average R2 = 0.92 for women and R2 = 0.83 for men). World populations differ dramatically in musculoskeletal slenderness (up to a difference of 4.4 kg/m2), as do men and women (differences of 3.3–4.5 kg/m2), leading to clear population corrections. These findings point to a conceptually straightforward tool for estimating true differences in adiposity across populations, and suggest an alternative to BMI that provides a more accurate and theoretically based estimate of body fat than that traditionally derived from height and weight measures. Am J Phys Anthropol 151:68–76, 2013. © 2013 Wiley Periodicals, Inc.

Gordon, Adam D.; Johnson, Steig E.; Louis, Edward E.

doi: 10.1002/ajpa.22259pmid: 23595644

Previous work in primates has shown that body size often covaries with ecological parameters related to resource or energy availability in the environment. This relationship may differ for males and females as access to resources has greater importance for reproductive success in females. We test the hypotheses that (1) female body mass may be more tightly constrained than male body mass by ecological variables, and (2) female body mass may respond more strongly than male body mass to changes in ecological variables (i.e., population‐specific female mass may vary more across an ecological gradient than male mass). Specifically, we investigate the relationship between climatic variables and sex‐specific body mass in Propithecus, a genus in which species‐specific body mass has already been demonstrated to covary significantly with climatic variables. Data from 733 wild sifakas are used to identify sex‐specific body mass for 27 populations representing all nine described sifaka species, and climatic data for each population are derived from the WorldClim database. We use phylogenetic generalized least squares models to demonstrate that body mass in both sexes is significantly correlated with annual rainfall and number of dry months. Furthermore, coefficients of determination are always higher for female models, and coefficients for each climatic variable are higher for females in all significant models. These results support the two hypotheses tested, indicating that ecological forces can have a greater impact on female mass than on male mass in primates. Am J Phys Anthropol 151:77–87, 2013. © 2013 Wiley Periodicals, Inc.

Kurki, Helen K.

doi: 10.1002/ajpa.22243pmid: 23504988

Obstetric selection acts on the female pelvic canal to accommodate the human neonate and contributes to pelvic sexual dimorphism. There is a complex relationship between selection for obstetric sufficiency and for overall body size in humans. The relationship between selective pressures may differ among populations of different body sizes and proportions, as pelvic canal dimensions vary among populations. Size and shape of the pelvic canal in relation to body size and shape were examined using nine skeletal samples (total female n = 57; male n = 84) from diverse geographical regions. Pelvic, vertebral, and lower limb bone measurements were collected. Principal component analyses demonstrate pelvic canal size and shape differences among the samples. Male multivariate variance in pelvic shape is greater than female variance for North and South Africans. High‐latitude samples have larger and broader bodies, and pelvic canals of larger size and, among females, relatively broader medio‐lateral dimensions relative to low‐latitude samples, which tend to display relatively expanded inlet antero‐posterior (A‐P) and posterior canal dimensions. Differences in canal shape exist among samples that are not associated with latitude or body size, suggesting independence of some canal shape characteristics from body size and shape. The South Africans are distinctive with very narrow bodies and small pelvic inlets relative to an elongated lower canal in A‐P and posterior lengths. Variation in pelvic canal geometry among populations is consistent with a high degree of evolvability in the human pelvis. Am J Phys Anthropol 151:88–101, 2013. © 2013 Wiley Periodicals, Inc.

Sosa, C.; Vispe, E.; Núñez, C.; Baeta, M.; Casalod, Y.; Bolea, M.; Hedges, R.E.M.; Martinez‐Jarreta, B.

doi: 10.1002/ajpa.22262pmid: 23595645

Ancient molecular typing depends on DNA survival in archaeological bones. Finding valuable tools to predict DNA presence in ancient samples, which can be measured prior to undertaking a genetic study, has become an important issue as a consequence of the peculiarities of archaeological samples. Since the survival of DNA is explained by complex interrelations of multiple variables, the aim of the present study was to analyze morphological, structural, chemical, and biological aspects of a set of medieval human bones, to provide an accurate reflection of the state of preservation of the bony components and to relate it with DNA presence. Archaeological bones that yielded amplifiable DNA presented high collagen content (generally more than 12%), low racemization values of aspartic acid (lesser than 0.08), leucine and glutamic acid, low infrared splitting factor, small size of crystallite, and more compact appearance of bone in the scanning electron micrographs. Whether these patterns are characteristic of ancient bones or specific of each burial site or specimen requires further investigation. Am J Phys Anthropol 151:102–109, 2013. © 2013 Wiley Periodicals, Inc.