The biological relationships of some prehistoric and historic Pueblo populations

Combined anatomical variations: The mylohyoid bridge, retromolar canal and accessory palatine canals branched from the canalis sinuosus

The study of anatomical variations is important not only for collecting anthropometric data, but also for improving clinical protocols and understanding why a particular clinical procedure sometimes does not yield the expected results. We report the case of a 74 year-old patient, in which we observed combined anatomical variants of the mandible and maxillary bone. One of these was the unilateral mylohyoid bridge (MB) of the uncommon, lingular type. This MB extended posteriorly to the spine of Spix, over the sulcus colli behind the spine. It thus formed a common mandibular canal (MC) which further divided into a retromolar canal and the MC proper. This combination of variants in the mandible has not, to our knowledge, previously been reported, at least in studies using cone beam computed tomography (CBCT). Additionally we found multiple accessory canals (ACs) deriving from the canalis sinuosus, which opened opposite to each frontal tooth, presumably carrying either dental fibers of the palatine nerves, or palatine fibers of the anterior superior alveolar nerve. Although the ACs in the anterior palate are well established anatomical variants, the MB appears in publications rather as an anthropological identifier. However, when present, it can impede anaesthesia of the lower teeth and thus deserves to be included in anatomical descriptions. The evaluation of patients in CBCT should observe the anatomical features on a case-by-case basis and it also provide data for studies of MB prevalence in large numbers of patients.

Body mass estimation from knee breadth, with application to early hominins

OBJECTIVES

The estimation of living body mass from skeletal dimensions is an important component of many studies of early hominins and more recent human archaeological remains. Most previous investigations have concentrated on weight-bearing elements of the lower limb, in particular the femoral head. In this study, we develop new body mass estimation equations derived from measurements of the knee in a modern sample of known body mass, and use them to estimate body mass in 11 fossil hominin specimens (including Au. africanus, Au. afarensis, and early Homo).

MATERIALS AND METHODS

The reference sample consisted of 100 living subjects who participated in the Baltimore Longitudinal Study of Aging. Mediolateral breadth measurements were taken from radiographs of the knee, and regressed against recorded body weight to generate body mass estimation equations.

RESULTS

Knee dimensions were generally found to be good predictors of body mass in the modern human sample, with median absolute percent prediction errors of 7 to 9% (comparable to or better than previously reported equations derived from the femoral head). Taxon-average estimated body masses were 46.1 kg for Au. afarensis, 38.4 kg for Au. africanus, and 53.6 kg for early Homo.

DISCUSSION

Estimates for early Homo were similar to or smaller than those generated previously from the femoral head. Estimates for australopiths, however, were larger than those generated from femoral head equations. This result is consistent with other evidence that the femoral head was relatively unloaded in australopiths compared with Homo, possibly due to subtle differences in gait. Am J Phys Anthropol 158:198-208, 2015. © 2015 Wiley Periodicals, Inc.

Phenotypic variation of transitional forager-farmers in the Sonoran Desert

This study examines phenotypic variation and biological distances estimated using morphological traits from three Early Agricultural period (EAP) (2100 BC-AD 50) site-complexes in the Sonoran Desert of southern Arizona and northern Sonora. The hypothesis tested is that EAP forager-farmers were phenotypically homogenous as suggested by patterns in material culture and works to refine inferences regarding gene flow and biological affinity during subsistence transitions. Seven measurements from 62 EAP male and female crania were collected and used to calculate phenotypic variances, biological distances, and FST values with RMET 5.0 software. Analyses were applied to both pooled site-complex samples and to males and females separately. Results show differential variation between site-complex population samples, multiple significant biological distances, and significant FST values for the EAP regional sample that indicate widespread phenotypic heterogeneity rather than homogeneity. Significantly lower than expected variance in the Cienega Creek male sample is inferred to suggest a small closely related population present during the Cienega phase. Greater than expected male variation is attributed to higher frequencies of gene flow in the La Playa and Santa Cruz River site-complex samples. These EAP males are inferred to be more mobile across the Sonoran Desert landscape and representative of multiple biological affinities compared with females. This study provides evidence supporting the canalization of phenotypic variation when associated with human populations becoming increasingly sedentary due to transitioning subsistence practices.

"Official" and "practical" kin: Inferring social and community structure from dental phenotype at Neolithic Çatalhöyük, Turkey

The Neolithic site of Çatalhöyük, Turkey (7400-5600 cal BC) is widely acknowledged for its role in the study of early farming communities. To better understand the social and community structure of this setting, an intracemetery biological distance analysis was conducted. Metric and nonmetric observations were recorded in both deciduous and permanent dentitions (n = 266) to explore phenotypic patterning of individuals interred within individual buildings. Specifically, this study tests the hypothesis that individuals within houses and house groupings represent family units and the social structure of Çatalhöyük was largely biological-kin based. Multivariate and univariate statistical procedures were applied to phenotypic dental data. Results indicate that inclusion for interment within a house was only minimally related to biological affinity. Moreover, the site does not appear to be organized into larger, biologically related neighborhoods of houses. These findings suggest that Çatalhöyük may not have been a kin-based society, largely because membership within a house cemetery was not solely defined on the basis of biological affinity, such as in a family group. Rather, it appears that social structure was centered on the house as the unifying social principle. The choice for interment location may have transcended biological lines thereby creating an alternate and more fluid definition of "kin." These findings can be used to understand the transition to settled life and biological patterning in this Neolithic community.

Brief communication: preliminary radiocarbon dates from Florida crania in Hrdlička's gulf states catalog

Aleš Hrdlička produced a tremendous amount of data in his career, much of which was published in a series of catalogs by the US National Museum. The Gulf States catalog, for example, contains raw craniometric data for over 700 individuals from the state of Florida alone. However, many of these skeletons are poorly sourced by Hrdlička, thus limiting their utility in modern bioarchaeological analyses where context is critical. In particular, the age of the skeletal material is often based solely on associated material culture and information on the sites themselves is not presented by Hrdlička. To address this impasse we attempted radiocarbon dates for 10 of the largest Florida sites published in the Gulf States catalog. In addition, archival data in the form of unpublished field notes and personal correspondence were accessed to better contextualize the radiocarbon dates and to provide some guidance on the degree of temporal variability at the sites. Eight AMS radiocarbon dates were successful. Archival data was of variable quality per site. In some cases very little is known about the provenience of the specimens. In other cases, however, individual burials could be allocated to specific strata within specific mounds. The relevance of using published raw data is discussed with respect to the Howells and Boas Immigrant datasets and the impact the dissemination of these resources has had on the discipline.

Phenotypic approaches for understanding patterns of intracemetery biological variation

This paper reviews studies of phenotypic inheritance and microevolutionary processes in archaeological populations using data on cranial and dental phenotypic variation, often referred to as paleogenetics or biodistance analysis. The estimation of biological distances between populations, or among individuals within populations, is one component of bioarchaeological research on past populations. In this overview, five approaches that focus on morphological variation within cemeteries are summarized: kinship and cemetery structure analysis, postmarital residence analysis, sample aggregate phenotypic variability, temporal microchronology, and age-structured phenotypic variation. Previous research, theoretical justifications, and methods are outlined for each topic. Case studies are presented that illustrate these theoretical and methodological bases, as well as demonstrate the kinds of inferences possible using these approaches. Kinship and cemetery structure analysis seeks to identify the members of family groups within larger cemeteries or determine whether cemeteries were kin-structured. Analysis of sex-specific phenotypic variation allows estimation of postmarital residence practices, which is important for understanding other aspects of prehistoric social organization. Analysis of aggregate phenotypic variability can be used to infer site formation processes or cemetery catchment area. The study of temporal microchronologies can be used to evaluate provisional archaeological chronologies or study microevolutionary processes such as adaptive selection or changing patterns of gene flow. Finally, age-structured phenotypic variation can be reflective of selection processes within populations or it can be used as a measure of morbidity, growth arrest, and early mortality within past populations. Use of phenotypic data as a genotypic proxy is theoretically sound, even at small scales of analysis.

Postmarital residence and biological variation at Pueblo Bonito

Although the social organization of many of the present-day pueblos of the American Southwest is well-described in the anthropological literature, many aspects of prehistoric Puebloan social organization have received limited attention since initial investigations of postmarital residence in the 1960s and 1970s. This paper examines postmarital residence at the Chaco Canyon great house of Pueblo Bonito, using biological data. Our findings are inconsistent with the previously well-accepted hypothesis that the Pueblo II and Pueblo III occupants of the San Juan Basin conformed to a socially prescribed pattern of matrilocal residence with matrilineal descent. Univariate variance differences for nine craniometric variables indicate a pattern of increased female variability consistent with patrilocal/bilocal residence. The results of multivariate determinant ratio analyses are in agreement with the univariate results, suggesting the possibility of a patrilocal or bilocal residence preference at Pueblo Bonito. These findings are inconsistent with the notion that the female-based system of matrilocal residence with matrilineal descent observed among the present-day Western Pueblos was the ancestral Anasazi condition.

Dental relatedness corresponding to mortuary patterning at Huaca Loro, Peru

Within and between tombs at the 1,000-year-old site of Huaca Loro on north coastal Peru, interment characteristics vary to an intriguing degree. Following and elaborating upon prior intracemetery studies, biological relatedness among associated burial groupings was assessed using 23 dental characters (assuming familial allele segregation) for 29 individuals. Biological patterning was based on multivariate distance between individuals using all traits, rather than the previously widespread reliance upon univariate comparison of each trait separately within samples. This multivariate approach did seem more informative. Statistically significant variation of biological similarities and dissimilarities corresponded to spatial groupings and also to various specific archaeological indications of the cohesiveness, or lack thereof, of interment pattern. The partition of biological distances among tombs at Huaca Loro supports the archaeological evidence that the tombs represent a planned elite cemetery.

Asymmetric vault modification in Hopi crania

Cradleboarding was practiced by numerous prehistoric and historic populations, including the Hopi. In this group, one result of cradleboarding was bilateral or asymmetric flattening of the posterior occipital. We test whether cradleboarding had significant effects on the morphology of the cranial vault, cranial base, and face. Additionally, we examine associations between direction of flattening and asymmetric craniofacial growth. A skeletal sample of Hopi from the Old Walpi site includes both nonmodified (N = 43) and modified individuals (N = 39). Three-dimensional coordinates of 53 landmarks were obtained using a diagraph. Thirty-six landmarks were used to define nine finite elements in the cranial vault, cranial base, and face. Finite element scaling was used to compare average nonmodified individuals, with averages of bilaterally, right, and left modified individuals. The significance of variation among "treatment" groups was evaluated using a bootstrap test. Pearson product-moment correlations test the association of asymmetry with direction of modification. Hopi cradleboarding has a significant effect on growth of the cranial vault, but does not affect morphology of the cranial base or face. Bilateral flattening of the cranial vault leads to decreased length and increased width of the cranial vault. Flattening of the right or left cranial vault results in ipsilaterally decreased length and width coupled with a corresponding increased length and width on the contralateral side of the cranial vault. There is a significant correlation of size asymmetry with direction of modification in the cranial vault, but not with size or shape change in the cranial base or face.

Cranial deformation and nonmetric trait variation

Cranial deformation is known to influence many traditional craniometric variables, but its effects on nonmetric trait variation are not well characterized. In this study, we examine the effects of three types of deformation (annular, lambdoid flattening, and fronto-occipital) on nonmetric traits, using a large sample of protohistoric and prehistoric crania. Our results indicate that a few traits are increased or decreased in relative frequency by particular types of deformation, but that these effects have little impact on the calculation of biological distances between groups.

Mylohyoid and jugular foramen bridging in pre-Columbian Chileans

The occurrence of mylohyoid groove bridging and jugular foramen bridging was determined in a population of adult Pre-Columbian Chileans. Two hundred forty-one crania (110 males, 131 females) were examined for jugular foramen bridging and 464 mandibles (252 males and 212 females) were observed for mylohyoid groove bridging. The overall incidence of jugular foramen bridging was 14.94%, with females showing a higher occurrence (18.32%) than males (10.91%); however, no statistical significance was found between the sexes. The right side showed a greater incidence than the left, but again no statistical difference was noted and the occurrence of this trait was found to be associated between the sides. This frequency of jugular foramen bridging is higher than that found in other studies and approaches that reported in North American Eskimo populations. In the case of mylohyoid groove bridging, the incidence was 4.09% with no difference found between the sexes. This frequency of occurrence is less than the values reported previously for the other American populations of Mongoloid ancestry including the Pre-Columbian Peruvian population. The importance of nonmetric skeletal traits for defining population groups and their usefulness as anthropological tools is discussed. It is concluded that hard tissue variations such as bony bridging may be reliable markers to aid in discretely identifying population groups, but their importance can be significantly enhanced by coupling as many traits as possible in future studies.

Skeletal biological distance studies in American physical anthropology: recent trends

Biological distance analysis, the dominant type of skeletal biological research during the 19th century, has become less visible in recent years. Although the proportion of American Journal of Physical Anthropology articles and published abstracts focusing on biodistance has remained fairly constant over the three decades between 1955 and 1985, the proportion of biodistance contributions relative to other skeletal biology studies has decreased. Emphasis in skeletal biology has shifted from the analysis of biological variation to investigations of health and diet, and within biodistance studies methodological issues have assumed prominence over purely analytical approaches. This paper investigates trends in biological distance analysis through a survey of articles and meetings abstracts published in the American Journal of Physical Anthropology from 1955 to 1985. The survey provides the historical context for five symposium papers on skeletal biological distance presented at the 1986 meeting of the American Association of Physical Anthropologists.

Migration models of prehistoric postmarital residence

It has previously been suggested that residential practices can be inferred from within- or between-group analysis of male and female skeletal morphology. Arguments have proceeded from intuitively derived hypotheses about the genetic consequences of drift and migration. In this paper, a formal basis is presented for these hypotheses using modified versions of Wright's island model and the migration matrix method. It is shown that the usual measures of standardized genetic variance or genetic kinship can be decomposed into male, female, and male/female components. The male and female components can in turn be used separately to assess the effect of different residential practices on the population genetic structure of the two sexes. Following upon these models, nonmetric cranial trait data from prehistoric sites in west-central Illinois are used to delineate the probable residential practices for this region.

Transverse relationships of the infraorbital foramina in cleft and noncleft individuals

An evaluation of the location of the infraorbital foramina in a transverse plane was undertaken by direct skull and radiographic measurements in unrepaired cleft palate and age- and sex-matched noncleft individuals. Physioprints were obtained on six dry skulls with left-sided clefts of the primary and secondary palates and on six age- and sex-matched noncleft palate skulls. The left infraorbital foramen was found to be significantly superior in a transverse plane to the right infraorbital foramen in the cleft palate skulls. No significant differences in transverse location of the infraorbital foramina were found in the cleft skull group based on differences in sex or age. Posterior-anterior cephalographs were obtained on 15 left unilateral cleft palate individuals and on age- and sex-matched noncleft palate individuals. The location of the infraorbital foramina in a transverse plane in the posterior-anterior cephalographs was found to be too variable to permit the use of parametric statistical tests. When the data on location of the infraorbital foramina were analyzed by a nonparametric statistical test it was found that the left infraorbital foramen was significantly superior to the right infraorbital foramen in the cleft palate individuals. The more superiorly placed infraorbital foramen on the cleft side was suggestive of a vertical deficiency of the maxilla on the cleft side.

Jugular foramen and mylohyoid bridging in an Asian Indian population

The incidence of jugular foramen and mylohyoid groove bridging was studied in a population of East Asian Indian skulls (125 males and 109 females). The criteria of Dodo (J. Anat. 144:153-165, 1986) was used in the identification of a jugular bridge. There was an overall incidence of 8.1% in jugular foramen bridging, with males showing a higher rate, though the difference did not reach statistical significance. The right side showed a statistically significant greater occurrence than the left, and the trait tended to be associated between sides. The overall incidence of mylohyoid bridging was found to be 2.6%, with no difference observed between the sexes. This frequency is less than the values reported for other Asian Indian studies. Studies concerned with the incidences of nonmetric traits such as bony bridging may be useful in population studies especially when utilized in combination, thereby enhancing the value of each trait as an anthropological tool.

The use of nonmetric variation in estimating human population admixture: a test case with Brazilian blacks, whites, and mulattos

Measurements in populations which serve as valid indicators of biological relationship should be proportional to genetic distance. In order to test the utility of discrete cranial traits for estimating genetic distances among populations, estimates of admixture are obtained for gene frequency data and nonmetric cranial data in São Paulo mulattos (M). The gene frequency data serve as a control that the three populations are related as stated: estimates of admixture are obtained by using São Paulo whites (W) and blacks (B) as parental populations and by estimating the parameter of admixture, m, in the model pM = (1 - m) pW + mpB (Elston, 1971) where the p's are either gene frequencies or nonmetric trait frequencies. A test of goodness of fit of the model provides a means of ascertaining whether or not the data fit this linear model. While the gene frequency data indicate distances among the three populations which are highly compatible with the linear model of admixture, the nonmetric data show significant deviations from the model. This implies that the frequencies of the nonmetric traits in the populations used in this analysis are not a linear function of genetic distance. This discourages the use of nonmetric traits in making quantitative conclusions about genetic relationships. It also suggests the need for investigation of the use of other skeletal characters for estimating genetic distance, as well as approaches for such investigations through the study of hybrid individuals.

The mylohyoid bridge in four population samples from India, with observations on its suitability as a genetic marker

Four adult skeletal samples from the states of Uttar Pradesh, Andhra Pradesh, and Bihar in India have been studied for the incidence of mylohyoid bridge. The incidence, varying between 2.98% and 7.14%, has been compared with frequencies reported for other populations of the world. The range of variation for Indians, as a whole, falls within the lower levels of the spectrum of worldwide variation for this trait, ranging between 0.47% for French Europeans and 33.8% observed among Plains American Indians. While noting its possible significance for clinical purposes, the suitability of the mylohyoid bridge as a population genetic marker has been discussed. It is emphasized that its use as a genetic marker in isolation of other discrete traits has serious limitations. For meaningful population definition and relationships as many discrete variants as possible ought to be utilized.

Effects of protein-calorie malnutrition during suckling and post-weaning periods on discontinuous cranial traits in rats

The influences of protein-calorie malnutrition (PCM), and sex during lactation and post-lactation on the frequencies of 25 discontinuous cranial traits (DCT), were investigated in Holtzman rats. Significant differences were observed in about 20% of the traits. Those traits were: the interfrontal fusion, the posterior incurvation of the palatine border, the double maxillary foramen, the double posterior palatine foramen, and the double frontal foramen. Total PCM was the nutritional factor which showed the greatest influence on the variability of the DCTs. It was followed, in decreasing order, by the PCM imposed during post-lactation and lactation. Sex had more influence than early PCM but less than late PCM. It is concluded that despite their apparent stability, a substantial number of DCTs were altered by both biological (like sex) and environmental factors (like nutritional deficiencies) imposed at different stages of postnatal development.

Differences in intracortical bone remodeling in three aboriginal American populations: possible dietary factors

Cross sections of intracortical bone revealed differences among three early American populations--Eskimo, Arikara, and Pueblo--in the frequency of a form of remodeling called, here, type II. This remodeling appears to occur exclusively within the walls of haversian canals of well-mineralized osteons. The populations are known to have differed in their nutrition. The Eskimo, with a high-protein diet, exhibited the most frequent type II remodeling, whereas the Pueblo, with a low-protein diet, showed the least. Type II remodeling probably reflects the physiological state of the group. Variation in frequency of classic intracortical bone remodeling was not apparent.

Size and morphology of the permanent dentition in prehistoric Ohio Valley Amerindians

Metric and morphological characterizations of the permanent teeth from a total of 155 prehistoric Amerindians are presented. The individuals represent samples from three Ohio Valley burial complexes (considered together as the Late Diffuse group): Glacial Kame, Adena and Ohio Hopewell. Metric data include common measures of central tendency and dispersion. From these measures estimates and analyses of the magnitude of sexual dimorphism and relative variability are presented as well as analyses of the patterns of these estimates. Forty morphological characters are also tabulated. The results indicate a number of provisional hypotheses: the generally larger tooth size of the Late Archaic Indian Knoll when compared to the Late Diffuse groups is consistent with the hypothesis of mitigated selective pressures in more technologically advanced groups; although tooth size is smaller in the Late Diffuse groups, dental morphology is as complex, or more so when compared to the Indian Knoll group. Since morphology and size do not covary exactly the biocultural forces resulting in smaller tooth size do not seem to act as strongly on dental morphology; odontological differences within the Late Diffuse arise primarily between the Glacial Kame-Adena and the Ohio Hopewell. These differences correspond to major biocultural changes in this area; although provisional hypotheses concerning odontological variability are erected, hypotheses concerning evolutionary trends must await the discovery of evolving lineages within these groups; similarities are noted among all compared groups including the pattern and magnitude of sexual dimorphism and relative variability. These parameters may be similar for all eastern Amerindians during this period; finally, the morphology of the deciduous dentition, which generally predicts that of the permanent teeth, is found to be less complex than the permanent teeth. This may be the result of a selective disadvantage for the individuals in the deciduous dentition sample which is reflected in the dentition.

Cortical bone loss with age in three native American populations

Age-related thinning of cortical bone was investigated in archaeological populations of Eskimos, Pueblos, and Arikaras. Medial-lateral cortical thickness was measured on radiographs of humerus and femur, and thickness of the anterior femoral cortex was measured directly on samples taken for histologic study. Maximum length of the bones was used to calculate indices of relative cortical thickness, in order to minimize differences due to body size and build. Bone loss in the humerus begins before middle age in all three populations and, except for Eskimo males, the same is true of the anterior femoral cortex. In general, overall female loss of cortical bone amounts to two or three times that of the males, and in the case of the humerus and the anterior cortex of the femur, this difference is evident by middle age. The weight-bearing femoral medial-lateral cortex shows less sexual difference but has the greatest number of statistically significant differences between populations and the greatest contrast between populations in pattern of loss with age. It appears that of the cortical regions studied this is the area upon which environmental factors have the greatest effect, whereas areas more subject to tensile stress, the humerus and anterior femoral cortex, are less affected by these factors.

The estimation of sex on the basis of the talus and calcaneus

The present report records and describes sexual dimorphism of the talus and calcaneus in American Blacks and Whites from the Terry Collection housed in the Smithsonian Institution, Washington, D.C. The greater amount of sexual dimorphism was observed in the talus, where 81 percent of the study sample could be accurately sexed. Four discriminant functions based on measurements from the talus and/or the calcaneus allowed sexing 79 to 89% of the study sample accurately. The techniques developed were then applied to two North American Indian samples, and sex of the individuals in these samples was assessed with the same degree of accuracy.

The skeletal biology of the Virginia Indians

Statistical analysis of one eastern and two western Virginia Indian skeletal samples reveals a general association between geographical and biological distance. However, the data suggest the importance of gene flow as a factor in minimizing local microdifferentiation. Females appear to contribute a disproportionate share to gene flow. This may be attributed to the widespread and apparently frequent practice of acquiring females and children through capture during recurring warfare.