American Journal of Physical Anthropology

Books received

2008-06-13T15:06:00Z

No abstract.

Book review: Baboon Metaphysics: The Evolution of a Social Mind

Larissa Swedell — 2008-06-13T15:06:00Z

No abstract.

Age estimation of adolescent and young adult male and female skeletons II, epiphyseal union at the upper limb and scapular girdle in a modern Portuguese skeletal sample

Hugo F.V. Cardoso — 2008-06-13T15:06:00Z

This study completes previously reported ages for timing of epiphyseal union in the postcranial skeleton in a recent sample, with data from the scapula, clavicle, humerus, radius, and ulna. A sample of 121 individuals between the ages of 9 and 29 (females = 65, males = 56) was derived from the Lisbon documented skeletal collection. Epiphyseal union was scored at 16 anatomical locations, using a three-stage scheme: 1) no union; 2) partial union; and 3) completed union, all traces of fusion having disappeared. In the upper limb, the epiphyses of the elbow are the first to fuse at around 11 to 15 years of age, followed by those of the shoulder and wrist. In the scapular girdle, the coracoid area is the first to fuse, followed by the glenoid surface and remaining epiphyses, with the medial clavicle fusing last, by the age of 25-27. There is a sex difference in maturation, with females showing an advance relative to males of about 2 years in the upper limb. Sex differences in maturation are less noticeable in the scapular girdle, but data suggest that females are also ahead of males. Results suggest overall similar age ranges for stages of union as previous dry bone observations, but some studies show significant divergences which seem to derive from methodological issues. Although some radiographic reference standards provide comparable age ranges, they should probably be avoided when aging skeletal remains. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Proximal femoral anatomy of a sivaladapid primate from the late middle Eocene Pondaung formation (central Myanmar)

2008-06-03T15:21:00Z

The postcranial anatomy of the Asian sivaladapid adapiforms is still virtually undocumented, whereas dental remains of these primates have been known for several decades. Little is known about their positional behavior as a result. In this article, we describe a partial left femur of a medium-sized primate preserving its entire proximal portion and a significant length of its shaft. This fossil was recently recovered from the fossiliferous locality of Thamingyauk in the late middle Eocene Pondaung Formation (central Myanmar). This femur is considered to pertain to the same individual as two tarsal elements (fragmentary talus and calcaneus) from the same locality (same location), and attributed to a medium-sized sivaladapid adapiform primate (Kyitchaungia takaii). This new postcranial element provides the first documentation of femoral anatomy among Sivaladapidae from Asia. The mechanical implications deriving from the musculoskeletal interpretation of this bone indicate an animal that probably engaged in a kind of active arboreal quadrupedalism with some degree of proficiency in leaping. Even though many musculoskeletal aspects suggest that branch walking and running were important parts of its locomotor repertoire, in other details it appears that relatively complex movements at the hip joint were actually possible and probably associated with climbing or some hindlimb suspensory activities. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

The genetic divergence of prehistoric populations of the south-central Andes as established by means of craniometric traits

Héctor H. Varela, Tyler G. O'Brien, Jose A. Cocilovo — 2008-05-30T09:05:00Z

The peopling of the south-central Andean region can be determined by exploring a combination of cultural, economic, and biological factors that influence the structure of populations and determine particular dispersals of gene frequencies. Quantitative characters from 1,586 adult crania of both sexes from northern Chile, northwestern Argentina, and the Cochabamba valleys in Bolivia were analyzed employing multivariate statistical analyses. Biological distances, representing phenotypic variation between these regions and their subregions, were studied within a population genetics framework. An analysis of Mahalanobis D2 distances establishes two principle directions of interaction: the first between the Cochabamba valleys and northern Chile, and the second between the Cochabamba region and northwestern Argentina. The Chile and Argentina regions are shown to be less related to each other than each is to the Bolivian region. A higher mean genetic divergence is found for the entire region (FST = 0.195); with northwestern Argentina having the highest spatial isolation (FST = 0.143) and northern Chile the lowest (FST = 0.061). These results allow us to propose a populating model based on the dispersion of several lines from a common ancestral population similar to those who inhabited the Cochabamba valleys. These lines differentiated themselves in time and space according to the effective size and the rate of gene flow, eventually producing the human groups which inhabited the valleys of northern Chile and northwestern Argentina. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Relatedness in wild chimpanzees: Influence of paternity, male philopatry, and demographic factors

2008-05-30T09:05:00Z

In chimpanzees (Pan troglodytes), high-ranking males are expected to have high reproductive success and females typically emigrate upon reaching maturity. Although high average relatedness among males in the same social groups has been assumed, previous reports have indicated that relatedness among males is not necessarily significantly higher than that among females. The paternity of 11 offspring and the relatedness of 50 individuals in the M group of chimpanzees at Mahale Mountains National Park, Tanzania, were investigated using DNA analyses. We determined the fathers of 10 offspring. Two different alpha males sired a total of five offspring, whereas the other males had low reproductive success. The proportion of paternal half-sibling pairs among the 10 offspring was 15.6%. The average relatedness among mature males was significantly higher than that among mature females. The existence of an old male and the long tenure of one alpha male may have contributed to this significant difference. The average dyadic relatedness among mature natal individuals was significantly higher than that in natal-immigrant pairs in which the individuals came from different groups. The average relatedness among immigrant females was similar to that in pairs of natal and immigrant females, suggesting that the immigrants came from various groups. Thus, female transfer acts to maintain low average relatedness within the group. A comparison of our results to those from other study sites suggests that although the average relatedness among adult males does not reach the level of half-siblings, under some circumstances it can exceed the relatedness of females. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Book review: The Evolution of Modern Humans in Africa

Jennifer L. Thompson — 2008-05-23T13:40:00Z

No abstract.

Taxon combinations, parsimony analysis (PAUP*), and the taxonomy of the yellow-tailed woolly monkey, Lagothrix flavicauda

Luke J. Matthews, Alfred L. Rosenberger — 2008-05-23T13:40:00Z

The classifications of primates, in general, and platyrrhine primates, in particular, have been greatly revised subsequent to the rationale for taxonomic decisions shifting from one rooted in the biological species concept to one rooted solely in phylogenetic affiliations. Given the phylogenetic justification provided for revised taxonomies, the scientific validity of taxonomic distinctions can be rightly judged by the robusticity of the phylogenetic results supporting them. In this study, we empirically investigated taxonomic-sampling effects on a cladogram previously inferred from craniodental data for the woolly monkeys (Lagothrix). We conducted the study primarily through much greater sampling of species-level taxa (OTUs) after improving some character codings and under a variety of outgroup choices. The results indicate that alternative selections of species subsets from within genera produce various tree topologies. These results stand even after adjusting the character set and considering the potential role of interobserver disagreement. We conclude that specific taxon combinations, in this case, generic or species pairings, of the primary study group has a biasing effect in parsimony analysis, and that the cladistic rationale for resurrecting the Oreonax generic distinction for the yellow-tailed woolly monkey (Lagothrix flavicauda) is based on an artifact of idiosyncratic sampling within the study group below the genus level. Some recommendations to minimize the problem, which is prevalent in all cladistic analyses, are proposed. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Middle Eastern and European mtDNA lineages characterize populations from eastern Crete

Laisel Martinez, Sheyla Mirabal, Javier R. Luis, Rene J. Herrera — 2008-05-23T13:40:00Z

Throughout centuries, the geographic location of the island of Crete has been one of the leading factors shaping the composition of its population. Invasions and commercial and cultural ties at various time periods with European, Middle Eastern, and North African civilizations have created a collage of genetic and/or cultural influences from each of these regions within the island. Previous Y-chromosome diversity analyses uncovered pronounced differences in the frequency distribution of haplogroups from a mountain refugium and surrounding lowland populations of eastern Crete. In this study, the current geographic stratification of mtDNA haplotypes in eastern Crete was explored to elucidate potential sources of maternal gene flow. Our work includes a comparative characterization of two lowland collections from the Heraklion and Lasithi Prefectures in eastern Crete, as well as of an isolated mountain population from the Lasithi Plateau, all three previously examined using Y-chromosome markers. In addition to the presence of European mtDNA haplogroups in all three collections, our analyses reveal a significant contribution of Middle Eastern and Central Asian genetic signatures in the island of Crete, and particularly in the two populations from the Lasithi region at the eastern-most portion of the island. Close association between these Cretan groups and the Balkans can also be discerned, which in the case of the Lasithi Plateau corroborates previously uncovered Y-chromosome affiliations with the same geographic region. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Manufactured populations: What do contemporary reference skeletal collections represent? A comparative study using the Maxwell Museum documented collection

Debra A. Komar, Christopher Grivas — 2008-05-16T11:02:00Z

The extent to which archaeological or cemetery skeletal collections accurately represent the population from which they were drawn cannot be known. The creation of documented or forensic skeletal collections, derived from donation or autopsy, was intended to overcome many of the problems inherent in archaeological populations, yet it is misleading to assume such collections represent a specific or defined population. This study compares the documented skeletal collection curated at the Maxwell Museum to annual demographic information from three relevant populations: (i) the living population of New Mexico (NM), (ii) the deceased of NM, and (iii) the subset of decedents who undergo a medicolegal death investigation or autopsy. Results indicate that the Maxwell Documented collection differs significantly from all three populations in every variable examined: age, sex, ethnicity/race, cause, and manner of death. Collection development that relies on body donation or retention of unclaimed bodies under coroner/medical examiner statutes results in a biased sample, with significant overrepresentation of males, Whites, the elderly, those who die unnatural deaths and individuals with antemortem traumatic injury or surgical intervention. Equally problematic is the perception that the collection has documented race or ethnicity, when in fact only 17% was self-reported, while the affinity of the remaining individuals was determined by pathologists or other observers. Caution is warranted in how this and similar collections are used and interpreted by researchers. Although documented reference collections are useful in developing methods of estimating age or sex, they are not a proxy for modern or racially/ethnically defined populations. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Variation in limb proportions between Jomon foragers and Yayoi agriculturalists from prehistoric Japan

2008-05-16T11:02:00Z

Variation in limb proportions between prehistoric Jomon and Yayoi people of Japan are explored by this study. Jomon people were the descendents of Pleistocene nomads who migrated to the Japanese Islands around 30,000 yBP. Phenotypic and genotypic evidence indicates that Yayoi people were recent migrants to Japan from continental Northeast Asia who likely interbred with Jomon foragers. Limb proportions of Jomon and Yayoi people were compared using RMA regression and "Quick-Test" calculations to investigate relative variability between these two groups. Cluster and principal components analyses were performed on size-standardized limb lengths and used to compare Jomon and Yayoi people with other groups from various climatic zones. Elongated distal relative to proximal limb lengths were observed among Jomon compared to Yayoi people. Jomon limb proportions were similar to human groups from temperate/tropical climates at lower latitudes, while Yayoi limb proportions more closely resemble groups from colder climates at higher latitudes. Limb proportional similarities with groups from warmer environments among Jomon foragers likely reflect morphological changes following Pleistocene colonization of the Japanese Islands. Cold-derived limb proportions among the Yayoi people likely indicate retention of these traits following comparatively recent migrations to the Japanese Islands. Changes in limb proportions experienced by Jomon foragers and retention of cold-derived limb proportions among Yayoi people conform to previous findings that report changes in these proportions following long-standing evolution in a specific environment. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

The peopling of America: Craniofacial shape variation on a continental scale and its interpretation from an interdisciplinary view

2008-05-14T15:17:00Z

Twenty-two years ago, Greenberg, Turner and Zegura (Curr. Anthropol. 27,477-495, 1986) suggested a multidisciplinary model for the human settlement of the New World. Since their synthesis, several studies based mainly on partial evidence such as skull morphology and molecular genetics have presented competing, apparently mutually exclusive, settlement hypotheses. These contradictory views are represented by the genetic-based Single Wave or Out of Beringia models and the cranial morphology-based Two Components/Stocks model. Here, we present a geometric morphometric analysis of 576 late Pleistocene/early Holocene and modern skulls suggesting that the classical Paleoamerican and Mongoloid craniofacial patterns should be viewed as extremes of a continuous morphological variation. Our results also suggest that recent contact among Asian and American circumarctic populations took place during the Holocene. These results along with data from other fields are synthesized in a model for the settlement of the New World that considers, in an integrative and parsimonious way, evidence coming from genetics and physical anthropology. This model takes into account a founder population occupying Beringia during the last glaciation characterized by high craniofacial diversity, founder mtDNA and Y-chromosome lineages and some private autosomal alleles. After a Beringian population expansion, which could have occurred concomitant with their entry into America, more recent circumarctic gene flow would have enabled the dispersion of northeast Asian-derived characters and some particular genetic lineages from East Asia to America and vice versa. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Relationships between lower limb cross-sectional geometry and mobility: The case of a Neolithic sample from Italy

Damiano Marchi — 2008-05-09T12:03:00Z

This study investigates the relationships between lower limb robusticity and mobility in a Neolithic sample (LIG) from Italy (6th millennium BP). This study tests the hypothesis that the high femoral robusticity previously observed in the LIG sample is a consequence of the subsistence strategy (i.e., high mobility on uneven terrain) practiced by LIG. Cross-sectional geometric properties of the femur and tibia at midshaft of LIG (eight males and eight females) were collected and results compared to Late Upper Paleolithic (12 males, five females), Mesolithic (24 males, 8 females), and Eneolithic (28 males, 17 females) samples from other sites throughout Europe. The results show that the LIG sample does not show the reduction of lower limb robusticity that is characteristic of the Eneolithic sample, but rather that the LIG sample is most similar to the earlier, highly mobile, populations. This high level of robusticity in the LIG sample could reflect both their pastoral subsistence strategy combined with a rugged environment, as well as their earlier temporal position within the Neolithic. The results of this study further point to significant variation in male-female mobility patterns in the region, also possibly related to pastoral behavioral patterns. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Manual lateralization in early primates: A comparison of two mouse lemur species

Lisette M.C. Leliveld, Marina Scheumann, Elke Zimmermann — 2008-05-09T12:03:00Z

In humans, 90% of the population is right handed. Although population hand preference has been found in some primate species, the evolution of manual lateralization in primates is not yet clear. To gain insight into manual lateralization of ancestral primates, we studied hand usage in unspecialized quadrupedal, nocturnal lemurs, using a large sample size. We compared two closely related mouse lemur species to explore the variation of hand preference within the same genus. We tested 44 gray mouse lemurs and 19 Goodman's mouse lemurs in a forced food grasping task. The tests were videotaped. Measures of hand preference (i.e. the hand that is spontaneously chosen for a specific task) and successful hand usage (i.e. the hand that is successful in completing a specific task) were taken to explore manual lateralization. Both species showed manual lateralization at an individual, but not at a population level. Goodman's mouse lemurs showed stronger individual hand preferences than gray mouse lemurs. This suggests that strength in hand preference is variable within the same genus. No sex and age effects were found. The hand preference of offspring was negatively correlated to that of their mothers, but not correlated to that of their fathers. Thus, no clear genetic effect can be derived from these results. In the Goodman's mouse lemurs, hand preference increased with increasing task experience. However, successful hand usage was not affected by task experience, suggesting that successful hand usage is a more stable measurement for manual lateralization than hand preference. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

The influence of basal metabolic rate on blood pressure among indigenous Siberians

2008-05-09T12:03:00Z

Hypertension is an important global health issue and is currently increasing at a rapid pace in most industrializing nations. Although a number of risk factors have been linked with the development of hypertension, including obesity, high dietary sodium, and chronic psychosocial stress, these factors cannot fully explain the variation in blood pressure and hypertension rates that occurs within and between populations. The present study uses data collected on adults from three indigenous Siberian populations (Evenki, Buryat, and Yakut [Sakha]) to test the hypothesis of Luke et al. (Hypertension 43 (2004) 555-560) that basal metabolic rate (BMR) and blood pressure are positively associated independent of body size. When adjusted for body size and composition, as well as potentially confounding variables such as age, smoking status, ethnicity, and degree of urbanization, BMR was positively correlated with systolic blood pressure (SBP; P < 0.01) and pulse pressure (PP; P < 0.01); BMR showed a trend with diastolic blood pressure (DBP; P = 0.08). Thus, higher BMR is associated with higher SBP and PP; this is opposite the well-documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMRs of indigenous Siberians may help explain the relatively high blood pressures and hypertension rates documented among native Siberians in the post-Soviet period. These findings underscore the importance of considering the influence of biological adaptation to regional environmental conditions in structuring health changes associated with economic development and lifestyle change. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Placental efficiency and intrauterine resource allocation strategies in the common marmoset pregnancy

Julienne N. Rutherford, Suzette D. Tardif — 2008-05-09T12:03:00Z

Mothers and fetuses are expected to be in some degree of conflict over the allocation of maternal resources to fetal growth in the intrauterine environment. Variation in placental structure and function may be one way a fetus can communicate need and quality to its mother, potentially manipulating maternal investment in its favor. Whereas common marmosets typically produce twin litters, they regularly give birth to triplet litters in captivity. The addition of another fetus is a potential drain on maternal resource availability and thus a source of elevated conflict over resource allocation. Marmoset littermates share a single placental mass, so that differences in the ratio of fetal to placental weight across litter categories suggest the presence of differential intrauterine strategies of resource allocation. The fetal/placental weight ratio was calculated for 26 marmoset pregnancies, representing both twin and triplet litters, to test the hypothesis that triplet fetuses respond to intrauterine conflict by soliciting placental overgrowth as a means of accessing maternal resources. In fact, relative to fetal mass, the triplet marmoset placenta is significantly undergrown, with individual triplets associated with less placental mass than their twin counterparts, suggesting that the triplet placenta is relatively more efficient in its support of fetal growth. There still may be an important role for maternal-fetal conflict in the programming of placental structure and function. Placental adaptations that solicit potential increases of maternal investment may occur at the microscopic or metabolic level, and thus may not be reflected in the size of the placenta as a whole. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Boundaries and clines in the West Eurasian Y-chromosome landscape: Insights from the European part of Russia

2008-05-09T12:03:00Z

Previous studies of Y chromosome variation have revealed that western Europe, the Volga-Ural region, and the Caucasus differ dramatically with respect to Y-SNP haplogroup composition. The European part of Russia is situated in between these three regions; to determine if these differences reflect clines or boundaries in the Y-chromosome landscape, we analyzed 12 Y-SNPs in 545 males from 12 populations from the European part of Russia. The majority of Russian Y chromosomes (from 74% to 94%) belong to three Y chromosomal lineages [I-M170, R1a1-M17, and N3-TAT] that are also frequent in the rest of east Europe, north Europe, and/or in the Volga-Ural region. We find significant but low correlations between haplogroup frequencies and the geographic location of populations, suggesting gradual change in the Y chromosome gene pool across western Eurasia. However, we also find some significant boundaries between populations, suggesting that both isolation and migration have influenced the Y chromosome landscape. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Epidemiologic transition in an isolated indigenous community in the Valley of Oaxaca, Mexico

Robert M. Malina, Maria Eugenia Peña Reyes, Bertis B. Little — 2008-04-29T14:03:00Z

The objective of the present study is to analyze age-specific mortality in a rural indigenous community in the throes of a secular increase in size in the Valley of Oaxaca, southern Mexico, over 30 years, 1970-1999. Variation in mortality by age group was analyzed over time for evidence of an epidemiological transition. The seasonal rain pattern in the Valley of Oaxaca (83% from May through September) was evaluated for its relationship with mortality in wet and dry months. Mortality and causes of death changed markedly over the 30-year interval. Infant and preschool mortality, overall mortality, and causes of death changed from the 1970s through the 1990s. Prereproductive deaths (<15 years) predominated in the 1970s and were largely due to gastrointestinal and respiratory diseases, with periodic outbreaks of measles. Deaths of adults 65+ years predominated in the 1990s and were largely due to degenerative diseases usually associated with aging. The marked changes in age and causes of death over the three decades (epidemiologic transition from Stage I to Stage II) occurred concurrently with significant secular increases in body size in children, adolescents, and young adults, highlighting improved health and nutritional conditions in the community which is in early Stage II of the demographic transition. The demographic transition to Stage II is a leading indicator (15-25 years lag) for the onset of the secular trend, while the epidemiologic transition to Stage II is a predictor that the secular increase is in process in the study community. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Brief communication: Locomotor limb preferences in captive chimpanzees (Pan troglodytes): Implications for morphological asymmetries in limb bones

William D. Hopkins — 2008-04-29T14:03:00Z

Understanding the evolutionary origins of hemispheric specialization remains a topic of considerable interest in a variety of scientific disciplines. Whether nonhuman primates exhibit population-level limb preferences continues to be a controversial topic. In this study, limb preferences for ascending and descending locomotion were assessed as a means of examining the hypothesis that asymmetries in forelimb bones might be attributed to asymmetries in posture. The results indicated that captive chimpanzees showed a population-level leftward asymmetry in descending locomotion but no group bias for ascending locomotion. The results are consistent with previous behavioral studies in captive chimpanzees as well as studies on skeletal asymmetries of the forelimbs of chimpanzees. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Hair color measurement and variation

Michelle Vaughn, Roland van Oorschot, Swati Baindur-Hudson — 2008-04-29T14:03:00Z

Pigmentation of hair in humans has been investigated by medical scientists, anthropologists and, more recently, by forensic scientists. In every investigation, hair color must first be defined by the researchers. Subjective color assessment inhibits the reproducibility of experiments and the direct comparison of results. The aim of this study was to objectively measure human hair color and examine the variation found in a population with European ancestry, using the CIE L*a*b* color space. Observer-perceived hair colors were compared with self-reported hair colors and the color as measured by reflective spectrophotometry of 132 subjects of European ancestry. The presented data show that self-reported hair colors and observer-reported colors are similar; however, these categories are not necessarily the best way to categorize hair color for quantitative research. Using a two-step cluster analysis, hair color can be divided into categories or clusters based on spectrophotometric measurements in the CIE L*a*b* color space and these clusters can be well discriminated from each other. This separation is primarily based on the b* (yellow) color component and the clusters show agreement to observer-reported colors. This study illustrates the possibilities for and necessity of objectively defining the hair color phenotype for various downstream applications. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Predictors of reproductive success in female white-faced capuchins (Cebus capucinus)

Linda Marie Fedigan, Sarah D. Carnegie, Katharine M. Jack — 2008-04-29T14:03:00Z

Early investigations into variable reproductive success in nonhuman primates tended to focus on the benefits conferred by high dominance rank. However, the effect of high rank on individual reproductive success has been found to vary both intra- and interspecifically, requiring researchers to expand their investigations to include additional factors. Here we examine the age and rank of the mother, sex of the infant, group size, number of close kin, replacement of group males, and resource availability as possible predictors of female reproductive success in white-faced capuchins (Cebus capucinus) in the Santa Rosa sector of the Area de Conservación Guanacaste, Costa Rica. We examine the length of interbirth intervals (IBI) and infant survivorship as measures of individual reproductive success for the 31 adult females that resided in our three study groups between 1986 and 2007. The greatest predictor of IBI length was whether or not the first infant in the interval survived (number of matrilineal kin and resource availability were also significant predictors); while infant survivorship was most significantly predicted by the occurrence of a turnover in group males in the year following the birth of an infant (infant sex was also a significant factor). Based on these findings, we conclude that male and female reproductive strategies are at odds in this species, with male strategies strongly influencing female reproductive success. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Book review: Anthropological Genetics: Theory, Methods and Applications

Stephen L. Zegura — 2008-04-29T14:03:00Z

No abstract.

Book review: The Invisible Sex: Uncovering the Role of Women in Prehistory

Katharine MacDonald — 2008-04-29T14:03:00Z

No abstract.

Book review: The Evolution and History of Human Populations in South Asia

Andrew Kramer — 2008-04-29T14:03:00Z

No abstract.

Book review: Primate Origins: Adaptations and Evolution

Alfred L. Rosenberger — 2008-04-08T10:24:00Z

No abstract.

Investigating the specificity of periosteal reactions in pathology museum specimens

Darlene A. Weston — 2008-04-08T10:24:00Z

The relationship between periosteal new bone formation and a number of infectious and metabolic conditions frequently seen in archeological human skeletal remains was investigated by studying human long bones demonstrating periosteal new bone formation archived in two London, UK, pathology museums: the St. George's Hospital Pathology Museum and the Hunterian Museum. The samples were subjected to macroscopic and radiographic analysis to determine if the characteristics of their periosteal lesions were specific to the corresponding disease states. The results demonstrated that no qualitative or quantitative characteristics of the periosteal reactions emerged that were specific to individual disease states. It was established that disease progression, rather than disease type, was the most important determinant of periosteal lesion appearance. A critical analysis of the bioarcheology literature pertaining to the recording and interpretation of periosteal reactions determined that the varied pathogenesis of periosteal new bone formation has been largely ignored in favor of a diagnosis of "nonspecific infection." Assumptions regarding the infectious etiology of periosteal lesions have become embedded into the bioarcheology literature potentially skewing the results of skeletal population-based paleoepidemiological studies. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

A quantitative and descriptive approach to morphological variation of the endocranial base in modern humans

Emiliano Bruner, Maurizio Ripani — 2008-04-08T10:24:00Z

The cranial base is one of the major foci of interest in functional craniology. The evolution and morphogenesis of this structure are still poorly known and rather controversial because of multifactorial influences and polyphasic stages. Endocranial dynamics are associated anteriorly with the upper facial structures, laterally with the mandibular system and midsagittally with brain development. In the present study, we investigated the endocranial morphology of modern humans using 3D landmark-based approaches, i.e. geometric morphometrics and Euclidean distance matrix analysis. The structure of endocranial variation is poorly integrated, with only weak reciprocal influences among the three fossae. Some major variations are associated with changes in the posterior fossa, with possible consequences on the anterior areas. These main patterns of integration are hypothesized to be influenced by the connective tensors of the dura layers. Static allometry and sex differences are largely related to the ontogenetic sequences, characterized by early maturation of the anterior fossa with respect to the middle and posterior regions (i.e., relatively shorter posterior part of the planum sphenoideum and vertical lengthening of the clivus in males). The relative independence between the endocranial fossae, as well as their structural connection through the meningeal tensors, must be carefully considered in studies on the evolutionary dynamics, since they lead to mosaic changes through phylogeny. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Prehistoric trepanation in the Cuzco region of Peru: A view into an ancient Andean practice

Valerie A. Andrushko, John W. Verano — 2008-04-03T10:25:00Z

In this study, patterns of prehistoric trepanation in the southern highlands of Peru were examined through an analysis of 11 Cuzco-region burial sites. Trepanations were found in 66 individuals, with several individuals exhibiting more than one trepanation, for a total of 109 perforations observed. The predominant methods used were circular cutting and scraping - methods that proved highly successful with an overall 83% survival rate and little ensuing infection. Survival rates showed a significant increase over time, apparently reflecting improvements in trepanation technique through experimentation and practical experience. Practitioners avoided certain areas of the cranium and employed methods that reduced the likelihood of damage to the cerebral meninges and venous sinuses. In many cases, trepanation as a medical treatment appears to have been prompted by cranial trauma, a finding that corroborates other studies pointing to cranial trauma as a primary motivation for the surgical procedure. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Using ancient mtDNA to reconstruct the population history of northeastern North America

Beth Alison Schultz Shook, David Glenn Smith — 2008-04-03T10:25:00Z

Mitochondrial DNA (mtDNA) was extracted and analyzed from the skeletal remains of 44 individuals, representing four prehistoric populations, and compared to that from two other prehistoric and several contemporary Native American populations to investigate biological relationships and demographic history in northeastern North America. The mtDNA haplogroup frequencies of ancient human remains from the Morse (Red Ocher tradition, 2,700 BP) and Orendorf (Mississippian tradition, 800 BP) sites from the Central Illinois River Valley, and the Great Western Park (Western Basin tradition, 800 BP) and Glacial Kame (2,900 BP) populations from southwestern Ontario, change over time while maintaining a regional continuity between localities. Haplotype patterns suggest that some ancestors of present day Native Americans in northeastern North America have been in that region for at least 3,000 years but have experienced extensive gene flow throughout time, resulting, at least in part, from a demic expansion of ancestors of modern Algonquian-speaking people. However, genetic drift has also been a significant force, and together with a major population crash after European contact, has altered haplogroup frequencies and caused the loss of many haplotypes. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Mobility and subsistence economy: A diachronic comparison between two groups settled in the same geographical area (Liguria, Italy)

Vitale Sparacello, Damiano Marchi — 2008-04-03T10:25:00Z

The purpose of this article is to investigate temporal shifts in skeletal robusticity to infer behavioral changes in two populations (Neolithic, NEOL and Medieval, MED) settled in the same geographic area but involved in different subsistence economies (pastoralism and coastal resources exploitation). This comparison allows us to test the hypothesis that occupational stress and mobility in the same environment produce predictable changes in the robusticity of both upper and lower limbs. Results show a lower degree of humeral robusticity and a similar degree of humeral asymmetry in the two sexes in the MED population. These results are consistent with the relatively less stressful subsistence economy documented in the MED population relative to that of the NEOL. Lower limb results suggest that femoral robusticity does not correlate directly with the level of logistical mobility, but is instead due to the summation of several diverse factors that place biomechanical loads on the hindlimb, particularly unevenness of the terrain. However, female femoral gracility seems to indicate that below a certain "threshold" of mobility, i.e., movement over the natural terrain, terrain conformation is no longer the main contributing factor to femoral robusticity. The femoral shape index Ix/Iy declines through time, particularly in males. This agrees with the expected mobility of the samples based on archaeological and historical data, providing further evidence on the reliability of this index in inferring terrestrial mobility. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Problems in determination of skeletal lead burden in archaeological samples: An example from the First African Baptist Church population

L.E. Wittmers Jr., A.C. Aufderheide, J.G. Pounds, K.W. Jones, J.L. Angel — 2008-04-03T10:25:00Z

Human bone lead content has been demonstrated to be related to socioeconomic status, occupation and other social and environmental correlates. Skeletal tissue samples from 135 individuals from an early nineteenth century Philadelphia cemetery (First African Baptist Church) were studied by electrothermal atomic absorption spectrometry and x-ray fluorescence for lead content. High bone lead levels led to investigation of possible diagenetic effects. These were investigated by several different approaches including distribution of lead within bone by x-ray fluorescence, histological preservation, soil lead concentration and acidity as well as location and depth of burial. Bone lead levels were very high in children, exceeding those of the adult population that were buried in the cemetery, and also those of present day adults. The antemortem age-related increase in bone lead, reported in other studies, was not evidenced in this population. Lead was evenly deposited in areas of taphonomic bone destruction. Synchrotron x-ray fluorescence studies revealed no consistent pattern of lead microdistribution within the bone. Our conclusions are that postmortem diagenesis of lead ion has penetrated these archaeological bones to a degree that makes their original bone lead content irretrievable by any known method. Increased bone porosity is most likely responsible for the very high levels of lead found in bones of newborns and children. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Maintenance versus growth: Investigating the costs of immune activation among children in lowland Bolivia

T.W. McDade, V. Reyes-García, S. Tanner, T. Huanca, W.R. Leonard — 2008-03-26T15:37:00Z

Immune function is a central component of maintenance effort, and it provides critical protection against the potentially life threatening effects of pathogens. However, immune defenses are energetically expensive, and the resources they consume are not available to support other activities related to growth and/or reproduction. In our study we use a life history theory framework to investigate tradeoffs between maintenance effort and growth among children in a remote area of Amazonian Bolivia. Baseline concentrations of C-reactive protein (CRP) were measured in 309 2- to 10-year olds as an indicator of immune activation, and height was measured at baseline and three months later. Elevated CRP at baseline predicts smaller gains in height over the subsequent three months, with the costs to growth particularly high for 2- to 4-year olds and for those with low energy reserves (in the form of body fat) at the time of immunostimulation. These results provide evidence for a significant tradeoff between investment in immunity and growth in humans, and highlight an important physiological mechanism through which maintenance effort may have lasting effects on child growth and development. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Cross-sectional analysis of long bones, occupational activities and long-distance trade of the Classic Maya from Xcambó - Archaeological and osteological evidence

2008-03-26T15:37:00Z

Xcambó is a Classic period Maya site (250-700 AD) situated on the northern coast of Yucatan, Mexico. Archaeological evidence suggests that the site began as a salt production center but adopted a more administrative role as a commercial port in the Late Classic period. Economic growth, depending on its magnitude, could have affected the daily occupations of Xcambó's inhabitants. However, this is difficult to infer from the archaeological record. The aim of this study was to directly evaluate this possibility through skeletal analysis. Since diaphyseal robusticity and shape are predominantly influenced by mechanical loading history, long bone cross-sections can be used to access activity patterns. To this end, humeri and femora of 47 male and 35 female adult specimens from two Xcambó population samples were scrutinized. Our analysis satisfies general archaeological expectations and provides additional information on the population's physical response to economic growth. Decreasing robusticity and femoral anterior-posterior rigidity indicate an overall decrease in physical workload and mobility, concomitant with the site's increasing administrative function. We also observed a significant decrease in sexual dimorphism, possibly attributable to the differential response of male and female physical work spheres during socioeconomic change. In general, our findings suggest even nonsubsistence based socioeconomic change can significantly affect the bone structure of a population, rendering activity analysis an important aspect of the reconstruction of living conditions of past populations. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Osteological and dental markers of health in the transition from the Late Antique to the Early Medieval period in Croatia

Mario [Scaron]laus — 2008-03-26T15:37:00Z

The purpose of this study is to analyze health at the transition from the Late Antique (LA) to the Early Medieval (EM) period in Croatia. Results of the analyses of skeletal remains are compared with historical and archaeological data to test the hypothesis that the transition was catastrophic. An additional objective is to determine whether the transition was a uniform process, or differentially affected the past inhabitants of Croatia because of various local considerations. To accomplish this, four markers of health: cribra orbitalia, linear enamel hypoplasia, nonspecific periostitis, and trauma were compared in 981 skeletons: 477 from nine urban LA sites, and 504 from six rural EM sites. Data were collected by sex and age for individual, and for co-occurrences of various features. Because continental and Adriatic Croatia has different ecological features, data were specifically tabulated for the two regions. Comparisons between the continental and Adriatic regions of the LA series showed no significant differences in the frequencies of the analyzed markers of stress. Comparisons between the LA and EM series showed similar frequencies in continental Croatia - suggesting no significant discontinuity of living conditions, and a significant increase of cribra orbitalia, periostitis, and trauma frequencies during the EM period in Adriatic Croatia. The deterioration of living conditions primarily affected subadults and males. These data suggest that the transition from the LA to the EM period in Croatia was not a uniform process, but differentially affected population biology most likely because of local cultural, socio-economical or political considerations. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Growth-related changes in prehistoric Jomon and modern Japanese mandibles with emphasis on cortical bone distribution

Hitoshi Fukase, Gen Suwa — 2008-03-26T15:37:00Z

Cortical bone distribution of the anthropoid mandibular symphysis has been addressed in relation to mechanical stress generated by mastication. To examine whether or not bone mass and distribution patterns of the human mandibular symphysis could be interpreted as an example of functional adaptation, we compared the skeletal growth series of two populations, prehistoric Jomon, considered to represent a "robust" mandibular morphology associated with a presumed heavier masticatory load, and modern Japanese. Results showed that the adult Jomon symphysis possessed significantly greater bone mass and thicker cortical bone compared to the modern Japanese condition. However, the second moments of area did not differ significantly between the two, indicating comparable rigidity against bending. Furthermore, the Jomon mandibles of the infant to juvenile stages exhibited most of the adult characteristics, in both bone mass/distribution of the symphysis and in mandibular corpus/ramus morphologies. The present study also demonstrated the presence of a growth pattern of symphyseal cortical thickness, common to both the Jomon and the modern Japanese series. In both populations, subsequent to deciduous molar occlusion, cortical bone tends to be thickest at the inferolingual symphysis, at the location where the highest tensile stresses presumably occur during mastication. These findings suggest that the "robust" characteristics of the Jomon mandible are initially manifested early in development, and that the effect of mechanical stimulus to bone mass formation in the human symphysis is largely confined to a regulatory role during growth modeling. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Dental wear and oral pathology: Possible evidence and consequences of habitual use of teeth in a Swedish Neolithic sample

Petra Molnar — 2008-03-26T15:37:00Z

Atypical wear and oral lesions were studied in the dental remains from the Middle Neolithic Pitted Ware Culture site Ajvide on the island of Gotland in the Baltic Sea. Teeth (n = 764) from 17 males and 11 females were examined microscopically to document unusual wear, assess wear patterns and oral lesions as evidence of habitual behavior, and determine their effect on the oral health of this population. Five atypical wear types were observed: occlusal facets, occlusal excessive load, labial vertical striae, labial horizontal striae, and interproximal striae. Three oral lesions were recorded: chipping, periapical lesions, and dental tilting. Results indicate that teeth were used in a habitual manner at Ajvide, based on the morphology and regularity of the patterns of atypical wear. Differences were observed between the sexes, indicating gender-related differences in the habitual use of teeth. Some wear categories showed a significant correlation with age, signifying increased or accumulated wear with age. Statistically significant positive correlations were found in the molars between occlusal excessive load wear and periapical lesions as well as tilting. Other apparent links were also observed between chipping and vertical striae as well as excessive load, although these were not significant. This suggests a relationship between dental wear and dental pathologies at this site, suggesting that habitual use of teeth indirectly affected the general oral health at the site. Wear patterns, furthermore, seem to mirror both frequent activities as well as single events. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Brief communication: Paleopathology of the Kiik-Koba 1 Neandertal

Erik Trinkaus, Blaine Maley, Alexandra P. Buzhilova — 2008-03-20T12:59:00Z

The Kiik-Koba 1 Neandertal partial skeleton (canine, partial hands, partial leg, and feet), of a [ap]40-year-old probable male, exhibits a suite of pathological lesions, including hypercementosis, minor fibrous ossifications, pedal phalangeal fracture, and pronounced enthesopathies on the patella and calcanei in the context of no articular degenerations. The first two sets of lesions are related to age in the context of advanced dental attrition and physical strains. The third lesion joins a series of healed minor traumatic lesions among the Neandertals. The last represents either pronounced tendinous inflammation, albeit in the context of no articular degenerations, or a case of diffuse idiopathic skeletal hyperostosis (DISH) in the Late Pleistocene. Kiik-Koba 1 therefore adds to the high incidence of pathological lesions among the Neandertals and, if a diagnosis of DISH is correct, to a high frequency of this disorder among older Neandertals. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

The bipedalism of the Dmanisi hominins: Pigeon-toed early Homo?

Ian J. Wallace, Brigitte Demes, William L. Jungers, Martin Alvero, Anne Su — 2008-03-18T16:46:00Z

In the recent description of the hominin postcranial material from Dmanisi, Georgia, Lordkipanidze and colleagues (Lordkipanidze et al. [2007] Nature 449: 305-310) claim that the Dmanisi hominins walked with more medially oriented feet than do modern humans. They draw this functional inference from two postcranial features: a wide talar neck angle and a slight medial torsion of the tibia. However, we believe that the data provided by the authors fail to support their conclusions. Talar neck angle and tibial torsion values from the Dmanisi specimens fall comfortably within the range of modern human variation. We further submit that foot orientation cannot be reliably deduced from the tibia and talus alone. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Genetic investigation of the patrilineal kinship structure of early medieval Ireland

Brian McEvoy, Katharine Simms, Daniel G. Bradley — 2008-03-18T16:46:00Z

A previous study of Irish Y-chromosomes uncovered a likely patrilineal kinship basis to the most prominent early Irish tribal entity/kingdom, the Uí Néill, who dominated the North of the Island during the early medieval period (600-1,000 AD). However, it is unknown to what extent this was a general feature of the multitude of Irish kingdoms that existed over the same period. Irish surnames are patrilineally inherited in a similar manner to the Y-chromosome and their origin can often be traced to pre-existing tribal units. We genotyped 17 microsatellites in 247 Y-chromosomes from men with surnames that are purported to be derived from two different tribes (Eóganacht and Dál Cais) from the Southern province of Munster, as well as a third cohort of random names from the same geographic area. Although there is some sharing of Y-chromosomes between surnames of the same putative origin, there was no clear distinction between either grouping and the control, suggesting that the level of Uí Néill patrilineal kinship was not a universal feature of Irish tribal units. In turn this argues that an extensive extended clan or biological legacy of an eponymous founding ancestor was not necessarily a crucial factor in their establishment. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Septal aperture of the humerus in a mediaeval human skeletal population

Simon Mays — 2008-03-18T16:46:00Z

Humeral septal aperture is studied in a large Mediaeval skeletal series from England. The aims are to investigate associations between septal aperture and sex, age, side and humeral robusticity; and to evaluate any associations with relative projection of ulna coronoid and olecranon processes. In this way, it is hoped to shed light on age at occurrence and the causation of the trait. Results showed a paucity of cases in juveniles. In adults, the trait was more common in left bones and in females. No association was found with humeral robusticity or humero-ulnar conformation. Detailed morphological study of humeral septa of individuals with and without apertures suggested that septal aperture forms via resorption from the anterior surface of the septum. In this group, apertures appear generally to form in early adult life. It is suggested that in the study group septal aperture generally arises from impingement on the humeral septum by the coronoid and olecranon processes, chiefly the former. It is tentatively suggested that frequency of septal aperture may be an index of joint hypermobility in earlier populations. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Insights from the inside: Histological analysis of abnormal enamel microstructure associated with hypoplastic enamel defects in human teeth

C. Witzel, U. Kierdorf, M. Schultz, H. Kierdorf — 2008-03-18T16:46:00Z

We studied the abnormalities in enamel microstructure associated with enamel hypoplasia in human teeth from the early medieval (5th-7th century AD) cemetery of Barbing, Germany, using light and scanning electron microscopy. The main aim of the study was to test the hypothesis that by analyzing the microstructure of fully formed enamel it is possible to reconstruct the reaction pattern of secretory ameloblasts to stress events leading to enamel hypoplasia. From the histological findings, a sequence of increasing impairment of secretory ameloblast function involving three thresholds was deduced. Surpassing of each of these thresholds is assumed to result in characteristic changes in enamel microstructure attributable to specific functional/morphological alterations of secretory ameloblasts. Based on our results we propose a model identifying the principal factors influencing the reaction of secretory ameloblasts to stress. The present study demonstrates that by including microscopic analysis in the study of enamel hypoplasia, it is possible to obtain a more complete picture of the formation of these developmental defects than is possible by inspection of crown surface features alone, and to draw more substantiated conclusions about the possible nature of developmental defects of enamel. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Ectocranial suture closure in Pan troglodytes and Gorilla gorilla: Pattern and phylogeny

James Cray Jr., Richard S. Meindl, Chet C. Sherwood, C. Owen Lovejoy — 2008-03-18T16:46:00Z

The order in which ectocranial sutures undergo fusion displays species-specific variation among primates. However, the precise relationship between suture closure and phylogenetic affinities is poorly understood. In this study, we used Guttman Scaling to determine if the modal progression of suture closure differs among Homo sapiens, Pan troglodytes, and Gorilla gorilla. Because DNA sequence homologies strongly suggest that P. troglodytes and Homo sapiens share a more recent common ancestor than either does with G. gorilla, we hypothesized that this phylogenetic relationship would be reflected in the suture closure patterns of these three taxa. Results indicated that while all three species do share a similar lateral-anterior closure pattern, G. gorilla exhibits a unique vault pattern, which, unlike humans and P. troglodytes, follows a strong posterior-to-anterior gradient. P. troglodytes is therefore more like Homo sapiens in suture synostosis. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.

Evaluation of juvenile stature and body mass prediction

Paul W. Sciulli, Samantha H. Blatt — 2008-03-18T16:46:00Z

This investigation evaluates the performance of juvenile stature (from tibia and radius lengths) and body mass (from breadth of the femoral distal metaphysis) prediction equations based on the Denver Growth Study sample (Ruff C. 2007. Am J Phys Anthropol 133 698-716). The sample used here for evaluation is an independent sample of juveniles brought to the Franklin County (Ohio) Coroner in 1990-1991. The Ohio sample differs somewhat from the Denver reference sample: it includes [sim]25% African-Americans (rather than all European-Americans), a significant number of right limb bones were measured (rather than all left side), it includes a wider range of economic statuses and it includes individuals who died from disease and trauma. As such the composition and measures of the Ohio sample correspond more generally to that seen in skeletal samples so that the accuracy of the estimates from the present sample should approach those found in practical applications of these methods. Results indicate that both juvenile body mass and stature are estimated relatively accurately. Accuracy of body mass estimates for 1-13-year-old juveniles is similar for African-American and European-American males and females. The least accurate estimates are for individuals in the 8-13 years age class (excluding individuals with body mass indices greater than the age specific 95th percentile): n = 9, ± 2.9 kg, 95% confidence interval 1.4-4.4 kg. Accuracy of stature estimates for 1-17-year-old juveniles is comparable for the tibia and radius and, as with body mass estimates, are similar for African-American and European-American males and females. For combined age, sex, and ancestry groups average accuracies are in the ±3.5 to ±6.5 cm range. Some limitations of the methods are discussed. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.