bluuebunny/crossref_metadata_2025 huggingface dataset:
Principal axis analysis of gene frequency data
Authors: Majumder Partha P.
Published: February 2006

When a set of populations are compared in respect of gene frequencies, and the chi‐square test of heterogeneity is found to be significant, it is pertinent to find out whether the heterogeneity can be explained by a few linear combinations of the gene frequencies, and the total heterogeneity chi‐square value can be partitioned as the sum of heterogeneity chi‐square values contributed by the linear combinations. The present report describes such a method, and the linear combination that explains the maximum heterogeneity is called the principal axis. An application of this method is presented to find clusters of 31 Mongoloid tribal populations of eastern India using ABO gene frequency data.
Gene frequencies and admixture estimates in the state of Puebla, Mexico
Authors: Lisker Rubén , Pérez‐Briceño Rocío , Granados Julio , Babinsky Victoria
Published: February 2006

Three hundred ninety‐three individuals from the Universidad Autonoma de Puebla and its University Hospital were studied to determine the distribution of ABO, MN, Rh‐Hr, Duffy, and Diego blood groups; red cell hemoglobin and glucose‐6‐phosphate dehydrogenase variants; and serum haptoglobins, albumins, and factor Bf types. With the results we estimated that the proportions of black, indian, and white genes are 10.7%, 56.3%, and 33.0%, respectively, in a trihybrid model. Reasons are given as to why the black ancestry may be artificially high, and it is pointed out that independent confirmation with other markers is needed before the figure can be accepted as a true value.
Brachydactyly, a possible inherited anomaly at prehistoric Prince Rupert Harbour
Authors: Cybulski Jerome S.
Published: February 2006

Disproportionately short metacarpals or metatarsals in eight burial skeletons and three unusually short metapodials recovered as disturbed bones were identified in a 1500 B.C. to A.D. 500 skeletal series from eight archeological sites of the north mainland coast of British Columbia, Canada. At least ten people were affected from four sites for a minimum series frequency of 5.2%. Various factors clinically implicated in the occurrence of brachy‐metapody were investigated to account for the anomaly. Context‐sensitive information suggested that trauma, infarction or infection, and individual or family‐related malformation syndromes were unlikely possibilities. Some modern population data suggest that the series frequency was unusually high, particularly for fourth metatarsal involvement, the most commonly affected bone. Modern pedigree interpretations, ethnohistoric inferences, and the archeological contexts of the affected burial skeletons and site samples provide a framework for concluding that brachymetapody in the series was more likely due to the inheritance of an essentially isolated anomaly.
Activity‐induced patterns of dental abrasion in prehistoric Pakistan: Evidence from Mehrgarh and Harappa
Authors: Lukacs John R. , Pastor Robert F.
Published: February 2006

A detailed investigation of worn teeth should reveal a record of past activity patterns including information regarding diet, food preparation methods, and craft or occupational activities.

Anthropological studies of the extensive dental samples from Neolithic (MR 3) and Chalcolithic (MR 2) levels at Mehrgarh, Baluchistan, and Bronze Age Harappa, Punjab, yielded several interesting examples of unusual dental abrasion. This paper provides macro‐ and microscopic (scanning electron microscope) descriptions of three types of activity‐induced dental abrasion: 1) interproximal tooth grooving and interproximal abrasion patches, 2) facial abrasion of maxillary anterior teeth, and 3) lingual abrasion of maxillary incisors in association with rounded wear of lower incisors. The gross size and shape of abrasion features, the orientation of microscopic wear striae, and ethnographic parallels are employed in inferring causal factors involved in their formation.

Behavioral activities and dietary explanations possibly associated with each type of dental wear are considered and their implications for reconstructing prehistoric activity patterns discussed. The need for extensive ethno‐anthropology research into variations of tooth use among living people with different diets, subsistence bases, and craft specializations is essential to further progress in this field.
Fossil Platyrrhine forelimb bones from the early miocene of Argentina
Authors: Anapol Fred , Fleagle John G.
Published: February 2006

Primate scapula and ulna fragments of uncertain taxonomic affinity (MACN‐SC 101) have been recovered from the Pinturas deposits at Arroyo Feo, Santa Cruz, Argentina in association with Santacrucian (Early Miocene) land mammals. Least‐squares regression of body weight on surface area and on height of the glenoid fossa of the scapula indicates an estimated mean weight of 3.6 kg for this individual.

On the basis of qualitative and several metric features, the fossil scapula and ulna most closely resemble living platyrrhine monkeys. In estimated body weight and relative height of the coronoid process, the fossil is similar to arboreal quadrupeds, such as Cebus apella and Chiropotes. However, spinoglenoid, axilloglenoid, and axillospinal angles, length of lever arm, and length and breadth of the sigmoid notch imply behavioral similarity with larger species that also use their forelimbs extensively in climbing, such as Alouatta and Lagothrix. MACN‐SC 101 may represent the incipient divergence of a generalized platyrrhine arboreal quadruped toward a more suspensory form.
Socioeconomic variation in estimated growth velocity of schoolchildren from a rural, subsistence agricultural community in southern Mexico
Authors: Little Bertis B. , Buschang Peter H. , Malina Robert M.
Published: February 2006

Socioeconomic variation in estimated growth velocities (annual growth increments) of several anthropometric dimensions was considered in schoolchildren from a rural, subsistence agricultural community in the Valley of Oaxaca in southern Mexico. The children (114 males, 99 females), 6–13 years of age, were measured twice, approximately one year apart. Annual growth increments were computed by subtracting measurements taken in the fall of 1978 from those taken in the fall of 1979. Information on household land holdings and appliances and parental occupation was used to compute an index of socioeconomic status (SES). Analysis of annual increments among upper SES (65 males, 45 females) and lower (49 males, 54 females) children indicated negligible differences. The results suggest that growth deficits evident in the children at school age occurred in infancy and early childhood so that there was little, if any, SES variation in growth rate at the school ages.
Genetic variation in the Aleuts of the Pribilof Islands and the Eskimos of Kodiak Island
Authors: Majumder Partha P. , Laughlin William S. , Ferrell Robert E.
Published: February 2006

A sample of Aleuts residing in the Pribilof Islands of St. Paul (N = 163) and St. George (N = 62) and Eskimo residents of Kodiak Island (N = 294) have been typed for genetic variation at 31 discrete genetic markers. Of these, 16 were polymorphic and 15 were monomorphic. Several private polymorphisms previously reported in Eskimo or Alaskan Amerindian populations were absent in both the Aleuts and Kodiak Island Eskimos. Genetic distance analysis shows considerable genetic differentiation between Aleuts and Kodiak Island Eskimos.
Three‐dimensional measurement accuracy of skull surface landmarks
Authors: Hildebolt Charles F. , Vannier Michael W.
Published: February 2006

Craniometric measuremnts from a three‐dimensional (3‐D) digitizing system were compared with those from sliding and spreading calipers. The 3‐D system consisted of a 3‐Space Digitizer, Macintosh Plus computer, and Unigraphics CAD/CAM system. Twenty‐nine standard measurements were made and repeated on two normal and three deformed skulls. The percentage of difference was calculated for original versus repeat measures and caliper versus 3‐D measures.

For objective anatomic structures and fiducial points, there was less than 2 mm (maximum) of difference between 1) the original digitizer versus repeat 3‐D measures and 2) caliper versus 3‐D measures. This represented 2% or less measurement incongruence. There were no significant differences for these comparisons (p > 0.1), and all regressions were highly significant (P < 0.001), with r2 > 0.999. 3‐D measurements were made more easily and quickly than were caliper measurements, with no loss in precision. It is concluded that 3‐D measurements are equivalent in quality to caliper measurements for craniometric studies, but are easier to obtain.
Maternal mortality in pre‐Columbian Indians of Arica, Chile
Authors: Arriaza Bernardo , Allison Marvin , Gerszten Enrique
Published: February 2006

A study of female mummies representing seven pre‐Columbian Andean populations of Arica, Chile, dating from 1300 B.C. (Azapa phase) to A.D. 1400 (Gentilar phase), disclosed that 18 (14% of the total) had died from childbirth‐complicated death (CCD). The majority of these individuals appear to have died during puerperium, three of them without complete delivery. Higher rates of CCD were found in the earlier cultural phases (1300 B.C.–A.D. 600) after which the maternal mortality rate decreased. The precise causes of this mortality are not known, but septic conditions, acute diseases, and cultural practices relating to birth are implicated.
Allometric relations of teeth and jaws in man
Authors: Kieser J. A. , Groeneveld H. T.
Published: February 2006

Static adult intraspecific allometry of jaws and teeth was investigated in a sample of 100 Negro crania. The relations between tooth area, postcanine surface, incisor surface, and four viscerocranial measures were examined separately for males and females. Our results indicate a marked lack of morphological integration between P‐sets within the orofacial subregion and a similar lack of correspondence between jaw size and tooth size. Allometric analyses indicate that mandibular length scales negatively allometric to maxilloalveolar length and to bigonial width, that canine base area scales positively to upper and lower jaw length, and that all the other teeth scale negatively to jaw length. The postcanine surface area was found to be negatively allometric to the canine base area, which in turn scaled isometrically to incisor surface. Hence, any lengthening of the mandible will tend to be associated with a relative shortening of the maxilla, with relatively larger canines and a relative reduction of the cheek teeth.
Increased heterozygosity and child growth in an isolated subsistence agricultural community in the valley of Oaxaca, Mexico
Authors: Little B. B. , Malina R. M. , Buschang P. H.
Published: February 2006

Gene flow and rate of inbreeding (ΔF) were calculated from demographic data for a community previously reported to be isolated from out‐side genetic influences of immigration. Significant child growth differences caused by gene flow among children born to native parents (n = 287) and offspring of native‐immigrant matings (n = 38) were found in fatness (triceps skinfold), body proportions (sitting height ratio), and size (leg length). No differences were found between the two groups in height, weight, sitting height, and arm circumference. Variation in absolute and relative leg length in this population parallels previously reported differences in adult body size and proportion associated with increased heterozygosity caused by gene flow in other populations in southern Mexico.
Isolation by distance on the Island of Korčula: Correlation analysis of distance measures
Authors: Rudan Pavao , Šimić Diana , Bennett Linda A.
Published: February 2006

Within the framework of holistic anthropological investigations of the rural populations on the Island of Korčula, various measures of biological distances between eight villages were estimated (Mahalanobis' D2 for anthropometric, physiological, and dermatoglyphic traits); socio‐cultural similarities and distances were determined (kinship coefficient estimated from migrational data and Hemming similarity measure estimated from linguistic data). A matrix of Spearman's rank correlation coefficients among these measures demonstrated a pattern of interdependencies, which we analysed further by principal components analysis. The first component reflects the cumulative effect of different processes acting on the initial gene distribution over a long period of time; the second component represents initial population structure; and the third component reflects recent migration influences.
The subarcuate fossa and cerebellum of extant primates: Comparative study of a skull‐brain interface
Authors: Gannon Patrick J. , Eden Avrim R. , Laitman Jeffrey T.
Published: February 2006

The subarcuate fossa of the petrosal bone houses the petrosal lobule of the cerebellar paraflocculus. Although the subarcuate fossa can be extensive, little is known about its relative size and distribution in primates. Studies indicate parafloccular involvement with cerebellar areas coordinating vestibular, visual, auditory, and locomotor systems. Hypotheses have proposed a role for the paraflocculus in vestibular‐oculomotor integration, caudal muscle control, autonomic function, and visual‐manual predation.

This study examines the morphology and relative extent of the subarcuate fossa/petrosal lobule in a range of living primates. Methods include study of postmortem specimens representing nine mammalian orders, and quantification of the volume of the subarcuate fossa and endocranial cavity in 155 dry primate crania of 36 genera. Results show that, in mammals, the size and morphology of the petrosal lobule is directly related to that of the subarcuate fossa. Craniometric analysis shows that the ratio of subarcuate fossa volume to endocranial volume is largest in lemuriforms. The largest ratio is in Microcebus and Hapalemur. Lorisids show a significant reduction in the size of the subarcuate fossa to almost 50% below the lemuriform mean. Tarsius is near the lemuriform mean. Among platyrrhines, the ratio is high, but significantly reduced compared to lemuriforms. The highest platyrrhine ratio is seen in Ateles, the lowest in Saimiri and Alouatta. Atelids are significantly elevated compared to cebids.

In cercopithecids, the fossa is significantly reduced compared to platyrrhines. The trend toward reduction of the cercopithecid fossa is most pronounced in Theropithecus and least evident in Presbytis. In hominoids, the fossa is present only in Hylobates. In great apes and humans, other than Gorilla, the petromastoid canal occupies a similar location to the subarcuate fossa of other primates, but is not homologous to it. Neither the subarcuate fossa nor the petromastoid canal are present in Gorilla.

A graded reduction of the subarcuate fossa/petrosal lobule is evident among primates which evolved later in time. The relative size of this cerebellar lobule within primates may reflect size‐related factors and/or degree of neocortical evolution as these relate to usage of a specific sensory‐mediated locomotor behavior. The subarcuate fossa may serve as an indicator of the differentiation of the petrosal lobule of the paraflocculus in fossil forms.
Technical report: A new method for endocranial reconstructions
Authors: Ross Karen C. , Wilczynski Walter , Albert James W.
Published: February 2006

A new method for construction of nonpermanent cranial endocasts is described. Endocasts are constructed using skulls from which skullcaps were removed at necropsy and retained. The endocasting medium is dissolved gelatin, which is biodegradable and water soluble, allowing recovery of the endocast with no permanent alteration of the skull. These endocasts are suitable for estimating brain weights and evaluating gross brain morphology.
Cranial base and jaw relationship
Authors: Kerr W. John S. , Philip Adams C.
Published: February 2006

The lateral skull radiographs of 124 boys aged approximately 10 years divided equally between the four angle classes were digitized in an effort to establish the relationship between cranial base size and shape and jaw relationship.

Comparison of the means for occlusal groups showed a trend from class II to class III as cranial base dimensions and angle decreased. The condyle was also more distally positioned with respect to nasion, point A and the Pterygomaxillary vertical in the class II groups.

Cranial base length correlated strongly with maxillary length but weakly with mandibular length. Nevertheless, the size of the maxilla did not influence its prognathism. The cranial base angle was strongly correlated (−0.7) with angle sella‐nasion‐point B.

It is concluded that cranial base size and shape influence mandibular prognathism by determining the anteroposterior position of the condyle relative to the facial profile.
Multiple correlations between craniofacial characteristics: An x‐ray study
Authors: Šmahel Zbyněk , Škvařilová Božena
Published: February 2006

The method of multiple correlations was used to assess the interrelations between basic characteristics of the facial bony framework and the cranial base. The study was based on x‐ray measurements in 50 normal adult males, and the result disclosed the extent to which the variability of the investigated characteristics was determined by the variability of several combined facial parameters.

The characteristics of shape and position of individual facial structures were more closely interrelated than characteristics of size. The lowest degree of association was shown by the parameters of the cranial base, which confirmed its independent development. The highest degree of interrelations was shown by the parameters of shape and position of the lower jaw, which characterized the marked adaptation and compensation capacity of the mandible. Some of these relations were causal. The present findings could be useful in orthodontic therapy and during anthropologic reconstructions.
Radiographic study of the humerus in Neandertals and Homo sapiens sapiens
Authors: Ben‐Itzhak S. , Smith P. , Bloom R. A.
Published: February 2006

Standardized mediolateral and anteroposterior radiographs of Neandertal and early and recent Homo sapiens sapiens humeri were taken from Europe and Israel. From these radiographs, maximum diameter and combined cortical thickness (CCT) were measured using vernier calipers. Cross‐sectional cortical area (CA), section modulus, and moment of inertia (I) were calculated using the appropriate formulae.

Male Neandertals had higher values for all parameters examined than early or recent H. sapiens s. and these differences were statistically significant in the right arm (P < 0.05). No significant differences in any parameter were found between early and recent H. sapiens s. Differences between female Neandertals and H. sapiens s. were less marked than those found between males. The male Neandertals also showed greater right‐left asymmetry in CCT, cortical area, section modulus, and moment of inertia than either female Neandertals or early or recent male H. sapiens s.

These findings add further support to hypotheses suggesting marked differences in muscle mass between Neandertals and H. sapiens s. They also indicate greater weight and/or functional differences between sexes in Neandertals than in H. sapiens s.
Repetition of the same pairs of names in marriages in Fogo Island, Newfoundland, and genetic variation
Authors: Koertvelyessy T. , Crawford M. H. , Huntsman R. G. , Collins M. , Keeping D. , Uttley M.
Published: February 2006

Surnames can be used to investigate the genetic structure of human populations. The repeated‐pairs approach (RP) uses information on the repetition of the same pairs of names from marital data sets to indicate the influence of clanlike behavior on mate choice. RP estimates the subdivision of the population into subgroups that breed among themselves and the kind of inbreeding ascribed to the Wahlund effect. The application of this method to the Fogo Island, Newfoundland, data set indicates a large percentage excess of observed over random repetitions. Presumably at least a part of this excess in the island population is due to denominational subdivision and endogamy. The expected relationship between RP and heterozygosity is observed in this case. Given these results, it would seem worthwhile to explore the relationship between the frequency of repetitions of pairs of surnames in marriages and genetic variation in other populations as well and, at the same time, to begin to inquire into the validity of such assumptions concerning the use of surnames as the monophyletic origin of common names.
Segregation analyses of the index fingerprint
Authors: Iagolnitzer E. R. , Darlu P.
Published: February 2006

Segregation analyses have been performed on both the ridge count and the pattern type (arch vs. nonarch) of the index fingerprints in a sample of 422 families. These analyses suggest a dominant autosomal major gene for arch and a recessive autosomal gene for low ridge count on the index finger. In both cases, multifactorial inheritance has to be taken into account. However, by testing different hypotheses, it turns out that the penetrance of arch trait is low (70%), and that the transmission parameters of the ridge count trait, although they are significant, diverge from the expected Mendelian values.
Comparative study of the upper molar occlusal table morphology among seven human populations
Authors: Kanazawa E. , Morris D. H. , Sekikawa M. , Ozaki T.
Published: February 2006

Three‐dimensional morphology of the occlusal table of the upper first molars was compared in seven racial populations. Materials were moiré contourograms collected by ourselves over 5 years. Intercuspal distances and cuspal heights were comparatively studied in this analysis. When the populations were arranged in the order of these sizes, their arrangements based on intercuspal distances and cuspal heights were quite different from each other. When intercuspal distances were scaled by protocone‐paracone distance, the distances connecting distal cusps were significantly smaller in Mongoloids (Japanese and Eskimo) than in Caucasoids (Dutch and Asiatic Indian), which suggests a reduction tendency of distal cusps in Mongoloids. This tendency was intermediate in Negroids and Australoid. Principal coordinate analysis was carried out on the basis of a similarity matrix including both intercuspal distances and cuspal heights. The result suggested that the three‐dimensional shape of the occlusal table was distinguishable in four representative racial populations.
Genetic structure of the saguenay, 1852–1911: Evidence from migration and isonymy matrices
Authors: Gradie Margaret I. , Jorde Lynn B. , Bouchard Gérard
Published: February 2006

The Saguenay is a region in northeastern Québec populated in the second half of the 19th century through migration from other parts of Québec. The present‐day population of nearly 300,000 is the result of both immigration and high rates of intrinsic growth. This population has been of interest to geneticists because of the high incidence of certain hereditary diseases, notably spastic ataxia, tyrosinemia, agenesis of the corpus callosum, vitamin D‐dependent rickets, and myotonic dystrophy.

Parent‐offspring migration and isonymy matrices were used to estimate random kinship using the Malécot model for six 10‐year time periods from 1852–1911. Comparisons between two estimates of kinship—one from parent‐offspring migration matrices (ϕ) and the other from isonymy (R)—and geographic distance were made using both product‐moment and Mantel correlation. Comparisons of within‐ and between‐subdivision kinship were made using nonparametric and Mantel correlation. Within‐subdivision kinship from the ϕ matrix was also compared with kinship estimated from marriage dispensations for endogamous marriages.

The estimates of random kinship from the parent‐offspring matrices showed a good fit with geography. However, isonymy did not correlate well with geographic distance; and ϕ and R showed no correlation until the last two time periods, and the diagonal of ϕ did not correlate with the marriage dispensations. Examination of scatterplots of ϕ vs. R suggests that nonrandom migration during the process of settlement formation is responsible for the lack of correlation. While movement across space seems to be highly dependent on distance, nonrandom selection of migrants means that between‐subdivision estimates of kinship based on migration are not congruent with those obtained by other methods. On the whole, genetic differentiation seems to have been low due to the high levels of movement between subdivisions and immigration. The weak dependence of genetic structure on geographic distances in the present population is demonstrated by mapping the geographic distribution of cases of three recessively inherited diseases.
Kin preference in marmosets and tamarins: Saguinus oedipus and Callithrix jacchus (callitrichidae, primates)
Authors: Harrison Mary L. , Tardif Suzette D.
Published: February 2006

Field studies on callitrichid primates have suggested that some species may exhibit a communal breeding system in which two or more males mate with a single female and cooperatively participate in infant rearing. However, high levels of aggression have been observed between males under both laboratory and field conditions. In avian models for communal breeding, cooperating males are often closely related. In a laboratory test of a hypothesis of the amelioration of aggression based on kinship, four mated pairs of both Saguinus oedipus and Callithrix jacchus were introduced to both novel male conspecifics and to their own male siblings, from whom they had been separated for a minimum of 4 months. Significant differences (P < .01) were seen in the responses of the two species to male conspecifics generally: S. oedipus males responded to intruders with overt aggression significantly more frequently than did marmosets while C. jacchus males more frequently scent‐marked than did tamarins. Evidence of preference for kin males was seen in the significantly decreased frequencies of these behaviors in the presence of kin males over those observed in the presence of novel males. It is argued that, under field conditions, cooperation between male callitrichids may be facilitated by kinship. Further, twin births, short gestation lengths, and interbirth intervals seen in callitrichid primates all contribute to the number of socially familiar kin with which an individual animal might cooperate.
Sexual selection and canine dimorphism in new world monkeys
Authors: Kay R. F. , Plavcan J. M. , Glander K. E. , Wright P. C.
Published: February 2006

Social and ecological factors are important in shaping sexual dimorphism in Anthropoidea, but there is also a tendency for body‐size dimorphism and canine dimorphism to increase with increased body size (Rensch's rule) (Rensch: Evolution Above the Species Level. London: Methuen, 1959.) Most ecologists interpret Rensch's rule to be a consequence of social and ecological selective factors that covary with body size, but recent claims have been advanced that dimorphism is principally a consequence of selection for increased body size alone. Here we assess the effects of body size, body‐size dimorphism, and social structure on canine dimorphism among platyrrhine monkeys.

Platyrrhine species examined are classified into four behavioral groups reflecting the intensity of intermale competition for access to females or to limiting resources. As canine dimorphism increases, so does the level of inter‐male competition. Those species with monogamous and polyandrous social structures have the lowest canine dimorphism, while those with dominance rank hierarchies of males have the most canine dimorphism. Species with fission‐fusion social structures and transitory intermale breeding‐season competition fall between these extremes.

Among platyrrhines there is a significant positive correlation between body size and canine dimorphism However, within levels of competition, no significant correlation was found between the two. Also, with increased body size, body‐size dimorphism tends to increase, and this correlation holds in some cases within competition levels.

In an analysis of covariance, once the level of intermale competition is controlled for, neither molar size nor molar‐size dimorphism accounts for a significant part of the variance in canine dimorphism. A similar analysis using body weight as a measure of size and dimorphism yields a less clear‐cut picture: body weight contributes significantly to the model when the effects of the other factors are controlled. Finally, in a model using head and body length as a measure of size and dimorphism, all factors and the interactions between them are significant. We conclude that intermale competition among platyrrhine species is the most important factor explaining variations in canine dimorphism. The significant effects of size and size dimorphism in some models may be evidence that natural (as opposed to sexual) selection also plays a role in the evolution of increased canine dimorphism.
Group selection models with population substructure based on social interaction networks
Authors: Cheverud James M. , Diane Chepko‐Sade B. , Dow Malcolm M. , Sade Donald S.
Published: February 2006

Most models of evolution by group selection assume that groups have discrete boundaries with homogeneous levels of interaction within groups and no interaction between groups. While this assumption is analytically useful, it is not an accurate description of groups in nature. We use a generalization of D.S. Wilson's (Am. Nat. 111:157–185, 1977; The Natural Selection of Populations and Communities. Reading, Mass.: Benjamin/Cummings, 1980) concept of trait‐groups, in which groups are defined as sets of interacting individuals, to estimate the average degree of relatedness among groomers and groomees, referred to here as grooming‐groups. The average degree of relatedness is an important parameter in models of both kin and group selection.

Data on grooming among 52 female rhesus macaques drawn from Group F on Cayo Santiago were used to represent the pattern and intensity of affiliative interactions. Degrees of relatedness among individuals and transferrin phenotypes were obtained from demographic and genetic records on the colony. The average degree of relatedness within grooming‐groups was estimated directly by calculating the average degree of relatedness among interactants (groomers and groomees), weighted by their frequency of interaction. Average degrees of relatedness among interactants were also estimated from the subjective frequency of the transferrin C allele.

Our analysis indicates that the average degree of relatedness within grooming‐groups is 0.316 when estimated directly and 0.347 when estimated from the subjective frequency of the transferrin C allele. These values are much higher than are usually considered for group selection in primate societies and indicate the relative ease with which altruism may evolve given primate social structures.
Statistical analysis of the migration component of genetic drift
Authors: Rogers Alan R. , Eriksson Aldur W.
Published: February 2006

Statistical methods are introduced for analysis of the migration component of genetic drift, i.e., of the stochastic changes that affect allele frequences during migration between local groups. Attention focuses on αM, a parameter that measures the extent to which this component of drift departs from the ideal of independent random sampling, and which can be interpreted as a measure of the extent to which migration is kin‐structured. It is shown that αM can be estimated from genetic data, even in the absence of information about the genealogical relationships of migrants, and Monte‐Carlo simulations are used to approximate the sampling distribution of the estimator under the null hypothesis of independent random sampling. Application of these methods to data from the Åland Islands, Finland, shows that the migration pattern there is consistent with the hypothesis of independent random sampling.
Human dental reduction: Natural selection or the probable mutation effect
Authors: Calcagno James M. , Gibson Kathleen R.
Published: February 2006

Dental reduction has been sufficiently widespread among human populations to render the phenomenon of reduced tooth size worthy of scientific explanation. One of the most controversial models invoked to explain structural reduction in organisms is referred to as the “probable mutation effect” (PME). According to this model, structures no longer functional owing to ecological or cultural changes will experience a relaxation of selection pressure, permitting an accumulation of mutations in the population that inevitably will result in the reduction in size or the loss of the concerned structure. Although the PME continues to be offered as a viable explanation of human dental reduction, it is based upon several premises that modern dental clinical experience fails to support. Known enzyme defects resulting from mutations, factors predisposing to dental infections, and the deleterious effects of teeth that are too large or too small reveal that the PME does not logically account for the reduction of tooth size. Given such information, this paper proposes models of dental reduction based upon natural selection, which, unlike the PME, are testable in both modern and archaeological populations. The integration of clinical and skeletal data permits a more thorough understanding of dental reduction in the hominid fossil record.
Gluteus maximus muscle function and the origin of hominid bipedality
Authors: Marzke Mary W. , Longhill Julie M. , Rasmussen Stanley A.
Published: February 2006

Bipedality not only frees the hands for tool use but also enhances tool use by allowing use of the trunk for leverage in applying force and thus imparting greater final velocity to tools. Since the weight and acceleration of the trunk and forelimbs on the hindlimbs must be counteracted by muscles such as m. gluteus maximus that control pelvic and trunk movements, it is suggested that the large size of the cranial portion of the human gluteus maximus muscle and its unique attachment to the dorsal ilium (which is apparent in the Makapan australopithecine ilium) may have contributed to the effectiveness with which trunk movement was exploited in early hominid foraging activities. To test this hypothesis, the cranial portions of both right and left muscles were investigated in six human subjects with electromyography during throwing, clubbing, digging, and lifting. The muscles were found to be significantly recruited when the trunk is used in throwing and clubbing, initiating rotation of the pelvis and braking it as trunk rotation ceases and the forelimb accelerates. They stabilize the pelvis during digging and exhibit marked and prolonged activity when the trunk is maintained in partial flexion during lifting of heavy objects.
Human skeletal and dental remains from Lapita sites (1600–500 B.C.) in the Mussau Islands, Melanesia
Authors: Kirch Patrick V. , Swindler Daris R. , Turner Christy G.
Published: February 2006

The Lapita Cultural Complex, radiometrically dated to between 3,600 and 2,500 B.P., is regarded on archaeological evidence as ancestral to modern Austronesian‐speaking cultures of eastern Melanesia and Polynesia. To date, there has been a lack of human skeletal and dental material from Lapita sites; thus, the present sample from Mussau Island, although small, offers an opportunity to present some preliminary observations of their importance to Oceanic prehistory. The present analysis, based mainly on teeth, suggests that the Mussau Island Lapita people had slightly closer affinities with Indonesian than with Melanesian populations. These results correspond well with linguistic and archaeological evidence regarding the origin of the Lapita Cultural Complex.
The genetic structure of populations of Chuckotka Peninsula Eskimos and Chuckchi based on the study of 13 loci of serum and erythrocyte proteins and enzymes
Authors: Nazarova Ariadna F.
Published: February 2006

The Eskimos and Chuckchi of the Chuckotka Peninsula were studied at 13 loci of serum and erythrocyte proteins and enzymes by electrophoresis. Six loci—including albumin, transferrin, carbonic anhydrase I and II, monoamine oxidase, and superoxide dismutase—were monomorphic in the studied populations. The mean frequencies of alleles in nine polymorphic loci of Chuckotka Eskimos and Chuckchi, Eskimos of Alaska, Canada, and Greenland, some Mongoloid populations of Siberia, American Indians, and Lapps of circumpolar areas of Western Europe were obtained. The genetic distances between these populations were calculated. The Eskimos of Chuckotka were closest to the Alaskan Eskimos. The relative heterozygosity of Chuckotka Eskimos was calculated and was the highest in Chuckchi. The average heterozygosity in Eskimo populations increased in the following order, from least to greatest: Chuckotka Eskimos, St. Lawrence Island Eskimos, Alaskan Eskimos, Greenland Eskimos, and Canadian Eskimos. The average heterozygosity of the Chuckchi was similar to that of Western Hemisphere Eskimos.
Extreme seasonality of births among nomadic Turkana pastoralists
Authors: Leslie Paul W. , Fry Peggy H.
Published: February 2006

Births to nomadic Turkana women in northwest Kenya follow one of the most highly seasonal distributions ever reported for a human population, with more than half of all births falling between March and June. Important aspects of the Turkana environment also fluctuate greatly over the course of the year. The rate of conception is apparently highest during the early dry season, when the food supply has been at its best for some time, and when women are attaining their peak nutritional status. The seasonal dynamics of Turkana fertility seem to be driven, ultimately, by fluctuations in rainfall; Fourier analysis indicates that changes in numbers of conceptions follow changes in rainfall with a lag of 3.6 months. The specific biological and behavioral changes in the human population through which the environmental changes may affect fertility are considered.
Test of Phenice's technique for determining sex from the os pubis
Authors: Lovell Nancy C.
Published: February 2006

Pubic bone morphology was examined to test the accuracy of Phenice's visual method for determining sex from the os pubis. Twelve participants scored 50 pubic bones from individuals of known sex aged 52–92 years. The sample is of modern males and females, all presumed whites. An accuracy of ∼83% in determining sex was recorded, compared to 95% reported by Phenice. This accuracy difference may reflect different age distributions of the two samples. Through replication of test results on two series of 25 specimens, the technique was found to be reliable. Previous experience in human osteological analysis was shown to have no effect on accuracy in this test, confirming Phenice's assertion that the technique does not require extensive experience to yield accurate results. Results suggest that there is a moderate negative correlation between accuracy in determining the sex of an individual and that individual's age.
Comparison of t‐tests for differences in sexual dimorphism between populations
Authors: Greene David Lee
Published: February 2006

A t‐test that can be used for evaluating the significance of differences in metric sexual dimorphism between populations is derived directly from mathematical considerations of the differences between distributions. It is compared with the t‐test derived by Relethford and Hodges (1985), which was based upon linear regression with sex as a dummy variable. Both are determined to be mathematically equivalent, though the one derived here is more similar in form to traditional t‐tests of differences and therefore may be simpler to employ. Both tests require only summary statistics for comparisons between populations and comparisons between generations within populations.
Sexual dimorphism in Laccopithecus robustus, a late Miocene Hominoid from China
Authors: Yuerong Pan , Waddle Diane M. , Fleagle John G.
Published: February 2006

Laccopithecus robustus is a siamang‐sized fossil ape from the Miocene site of Lufeng, China. The species is known from a partial cranium, numerous mandibles, and scores of isolated teeth. This species shows striking dental similarities to Pliopithecus from the Miocene of Europe and a number of cranial similarities to extant gibbons. Laccopithecus differs from extant gibbons and resembles other fossil and extant apes in showing marked sexual dimorphism in the size and shape of the canines and anterior lower premolars. Evidence for sexual differences in either the size or shape of other teeth is less clear. There is some evidence for a sexual size dimorphism based on the variability of molar teeth.
Social and biological correlates of localized enamel hypoplasia of the human deciduous canine tooth
Authors: Skinner M. F. , Hung J. T. W.
Published: February 2006

Recent studies of teeth from prehistoric children have reported a localized, roughly circular patch of deficient enamel on the labial aspect of the primary canine, which reaches its highest prevalence in the Upper Paleolithic of Europe. This study reports social and biological correlates of 33 affected kindergarten‐aged children from Vancouver, Canada (2.4% of 1,350 examined). Affected children can be characterized as coming from low‐income families often of East Asian or Chinese origin in which there is a degree of milk avoidance and reduced breastfeeding. The defect appears to be due to minor physical trauma to the face approximately 6 months after birth occasioned by normal motor development, involving handling and mouthing objects, which damages the developing tooth crown through deficient cortical bone over the canine crypt. Reduced cortical bone in the face of the infant is attributed to nutritional factors, involving calcium deficiency, of the mother and/or developing infant.
Population variation in tooth, jaw, and root size: A radiographic study of two populations in a high‐attrition environment
Authors: Smith Patricia , Wax Yochanan , Adler Fanny
Published: February 2006

Radiographs were taken of the jaws of skeletal remains of two populations of different‐phenotype Prehistoric Australians from Roonka and Early New Zealanders (Maoris). On these radiographs crown, root, and corpus size were measured. Corpus height was subdivided into alveolar bone height, defined as the bone superior to the mandibular canal, and basal bone height, defined as that inferior to the mandibular canal. Both between and within the two populations there was a significant and negative correlation between crown size and corpus height. The differences between the two populations in corpus height were associated with differences in alveolar bone height rather than basal bone height and support hypotheses associating continued eruption of adult teeth with growth of the alveolar bone. The findings also support previous studies that have shown only a low correlation between crown size, root size, and corpus height.
Third molar agenesis in human prehistoric populations of the Canary Islands
Authors: De Castro José María Bermúdez
Published: February 2006

The occurrence of third molar agenesis was recorded in a sample of 1,492 maxillary and 1,718 mandibular arches belonging to the prehistoric settlers of the Gan Canaria, Tenerife, and La Gomera Islands (Canary Islands). There were significant sex differences only in the Tenerife sample for the maxilla, the incidence in females being higher than in males. In the Gran Canaria sample, the total frequency (male and female combined) of third molar agenesis (individual count method) was 8.7% for the maxilla and 9.3% for the mandible. In the Tenerife and La Gomera samples, the frequencies were 11.1% and 10.7% for the maxilla and 14.6% and 13.3% for the mandible. In the Tenerife sample, the differences between both jaws were statistically significant. The incidence of missing third molars in the mandible was significantly higher in Tenerife than in Gran Canaria, but the other sample differences were statistically nonsignificant. Bilateral absence of third molars was observed in about two‐thirds of the specimens examined. Some correlation between both jaws for the occurrence of third molar agenesis was found. The hypotheses that have been proposed in order to explain third molar agenesis in man are discussed. It is suggested that the loss of the third molar in Homo sapiens could be produced by a heterochronic phenomenon of postdisplacement, as a consequence of the phylogenetic tendency toward the delay of the onset of the third molar formation, and that the genetic factors responsible for the absence of these teeth could be related to the general process of delay in tooth formation.
Apparent age‐related bone loss among adult female Gombe chimpanzees
Authors: Sumner Dale R. , Morbeck M. E. , Lobick J. J.
Published: February 2006

Apparent age‐related bone loss among adult females was observed in a skeletal sample derived from the free‐ranging Gombe chimpanzee population of Tanzania. Photon absorptiometric and computed tomographic bone scans indicated that, as in humans, bone was lost from the endosteal surface, but, in contrast to humans, more bone was lost from cortical sites than from cancellous sites. The etiology of this bone loss may be related to a number of factors, including hormonal changes, nutritional inadequacy, and decreased physical activity late in life.coupled with the demands of pregnancy and lactation.
Developmental changes in the facial soft tissues
Authors: Burke P. H. , Hughes‐Lawson C. A.
Published: February 2006

Short‐base stereophotogrammetry was used to study differential growth and development of the soft tissues of the face. Thirteen facial parameters were measured at ages 9, 11, 13, 15, and 16 years on 170 facial contour maps selected from a mixed longitudinal study of 26 boys and 26 girls. Each parameter was measured three‐dimensionally, and its developmental progress at the earlier stages was expressed as a percentage of its value at 16 years of age. Standing height development was assessed in the same way. Three parameters that measured soft tissues surrounding the eyes grew little but were very advanced in their development, following a “neural” pattern. The remaining facial parameters grew more but were less advanced, and standing height was least advanced. There appeared to be three separate patterns of development, “neural,” “facial,” and “skeletal.” Girls were, in general, smaller than boys, but their development was more advanced when measured as a percentage of size at 16 years compared with boys.
Treponematosis: A possible case from the late prehistoric of North Carolina
Authors: Reichs Kathleen J.
Published: February 2006

The skeleton of an adult female exhibiting evidence of trepo‐nemal infection was recently recovered from the Hardin site in the piedmont region of North Carolina. Archaeological indicators suggest a late prehistoric affiliation. The skeleton is affected by a diffuse process resulting in surface changes, both destructive and appositional, node formation and shaft expansion, medullary encroachment and filling, cortical thickening, and fracture. There is both cranial and postcranial involvement. While treponemal infection is indicated, the atypical nature of the total pattern raises the possibility of multiple pathological processes operating simultaneously.

The significance of this case is threefold. It provides information on the ability of prehistoric peoples to cope with disease. It reminds the paleopathologist of the dangers inherent in attempts at singular and specific diagnoses. It sheds new light on the epidemiology of the treponemal diseases.