Sex differences in radioulnar contrasts of the finger ridge counts across 21 human population samples.

Aim: The aim of the present study was to demonstrate the existence of uniform sexual dimorphism in some radioulnar contrasts between different finger ridge counts within the same hand in a large set of populations, thus confirming the universal nature of this dimorphism in humans.Subjects and methods: We analysed individual finger ridge counts (10 values on each hand) of both hands from archival sources (mainly the Brehme-Jantz database). In total, these included 4412 adults from 21 population samples covering all permanently inhabited continents and encompassing very different and geographically distant human populations. We calculated the contrasts (differences) of all pairs of ridge counts (45 per hand) and used diverse methods to assess the direction and degree of dimorphism of them across all population samples.Results: The highest sexual dimorphism was observed for nine contrasts involving the ridge count of the dermatoglyphic pattern on the radial side of the second finger of the right hand (R2r). Among these contrasts, we then found four that had the same direction of dimorphism in all 21 populations. The most dimorphic was the contrast R1rR2r - the difference between the ridge count of the radial side of the thumb and the radial side of the index finger.Discussion: Thus, these dermatoglyphic traits can be further investigated as potential markers of prenatal sex differentiation from ca. 10th week of intrauterine development. However, it will be useful to address the detailed factors and mechanisms for differences in the degree of dimorphism of these traits in different populations.

Limb bone allometry in modern Euro-Americans.

OBJECTIVES: The pattern of static and secular allometry was examined in a time series of limb bone lengths from individuals with birth years ranging from 1840 to 1989. The main hypothesis investigated was that secular changes in limb proportions, as seen in changes in the brachial and crural indices, can be explained by allometric responses to increasing size. MATERIALS AND METHODS: Maximum lengths of humerus, radius, femur, and tibia were obtained from 19th and 20th centuries identified skeletons. Allometry was investigated on two levels, static and secular. Static allometry was defined as average allometry within 20-year birth cohorts, and secular allometry as allometry among birth year cohorts. Allometry was assessed by extracting eigenvectors from covariance matrices of log transformed variables. Departures from allometry were examined using shape variables, and principal components of minor axes. RESULTS: Static covariance matrices were homogeneous. Eigenvectors extracted from the secular covariance matrix showed important departures from static allometry, particularly a much stronger negative allometry of the humerus and a stronger positive allometry of the tibia. Shape analysis showed that relative humerus length decreased significantly over the time period examined and relative tibia length increased. The last principal component, which combined aspects of the brachial and crural index, showed the highest variation among birth year cohorts. DISCUSSION: The results demonstrate that the secular changes in limb proportions cannot be explained by allometric responses to increasing size alone. The majority of variation among birth cohorts is found on the last PC and that suggests that canalized development has been disrupted by the unique environment in which modern Americans now live.

Cranial change in Americans: 1850-1975.

This paper examines the pattern and magnitude of craniofacial change in American blacks and whites over the past 125 years. Standard metric data from 885 crania were used to document the changes from 1850 to 1975. Data from 19th century crania were primarily from anatomical collections, and 20th century data were available from the forensic anthropology data bank. Canonical correlation was used to obtain a linear function of cranial variables that correlates maximally with year of birth. Canonical correlations of year of birth with the linear function of cranial measurements ranged from 0.55 to 0.71, demonstrating that cranial morphology is strongly dependent on year of birth. During the 125 years under consideration, cranial vaults have become markedly higher, somewhat narrower, with narrower faces. The changes in cranial morphology are probably in large part due to changes in growth at the cranial base due to improved environmental conditions. The changes are likely a combination of phenotypic plasticity and genetic changes over this period.

Variation among early North American crania.

The limited morphometric work on early American crania to date has treated them as a single, temporally defined group. This paper addresses the question of whether there is significant variability among ancient American crania. A sample of 11 crania (Spirit Cave, Wizards Beach, Browns Valley, Pelican Rapids, Prospect, Wet Gravel male, Wet Gravel female, Medicine Crow, Turin, Lime Creek, and Swanson Lake) dating from the early to mid Holocene was available. Some have recent accelerator mass spectrometry (AMS) dates, while others are dated geologically or archaeologically. All are in excess of 4500 BP, and most are 7000 BP or older. Measurements follow the definitions of Howells [(1973) Cranial variation in man, Cambridge: Harvard University). Some crania are incomplete, but 22 measurements were common to all fossils. Cranial variation was examined by calculating the Mahalanobis distance between each pair of fossils, using a pooled within sample covariance matrix estimated from the data of Howells. The distance relationships among crania suggest the presence of at least three distinct groups: 1) a middle Archaic Plains group (Turin and Medicine Crow), 2) a Paleo/Early Archaic Great Lakes/Plains group (Browns Valley, Pelican Rapids, Lime Creek), and 3) a spatially and temporally heterogeneous group that includes the Great Basin/Pacific Coast (Spirit Cave, Wizards Beach, Prospect) and Nebraska (Wet Gravel specimens and Swanson Lake). These crania were also compared to Howells' worldwide recent sample, which was expanded by including six additional American Indian samples. None of the fossils, except for the Wet Gravel male, shows any particular affinity to recent Native Americans; their greatest similarities are with Europe, Polynesia, or East Asia. Several crania would be atypical in any recent population for which we have data. Browns Valley, Pelican Rapids, and Lime Creek are the most distinctive. They provide evidence for the presence of an early population that bears no similarity to the morphometric pattern of recent American Indians or even to crania of comparable date in other regions of the continent. The heterogeneity among early American crania makes it inadvisable to pool them for purposes of morphometric analysis. Whether this heterogeneity results from different early migrations or one highly differentiated population cannot be established from our data. Our results are inconsistent with hypotheses of an ancestor-descendent relationship between early and late Holocene American populations. They suggest that the pattern of cranial variation is of recent origin, at least in the Plains region.

Archaeological politics and public interest in paleoamerican studies: lessons from Gordon Creek Woman and Kennewick Man.

This paper discusses the Kennewick lawsuit as it relates to the intended purposes of NAGPRA. It also reflects upon comments made by Swedlund and Anderson (1999) in a recent American Antiquity Forum, which conceptually linked two ancient skeletons, Gordon Creek Woman and Kennewick Man. Their assertions indicate the need for clarifying specific issues and events pertaining to the case. We comment on how times have changed with the passage of NAGPRA, how differently these two skeletons have been treated by the media and the scientists interested in them, and show how discussions of biological affiliation have relevance. There is still much to be learned from Kennewick Man and Gordon Creek Woman. But attempts to bring the concept of race or racial typing into the picture show misunderstanding regarding the use of morphological data in tracing population historical relationships, not to mention obfuscating the scientific issues they raise.

Secular change in craniofacial morphology.

Five craniofacial variables (glabella-occipital length, basion-bregma height, maximum cranial breadth, nasion-prosthion height, and bizygomatic breadth) were used to examine secular change in morphology from the mid-19(th) century to the 1970s. The 19(th) century data were obtained from the Terry and Hamann-Todd anatomical collections, and the 20(th) century data were obtained from the forensic anthropology databank. Data were available for Blacks and Whites of both sexes. Secular change was evaluated by regressing cranial variables on year of birth. Two analyses were conducted, one using the original variables and one using size and shape. Size is defined as the geometric mean of the cranial variables, and shape is the ratio of each variable to size. The results show remarkable changes in the size and shape of the cranial vault. Vault height increases in all groups in both absolute and relative terms. The vault also becomes longer and narrower, but these changes are less pronounced. Face changes are less than the vault changes, but to the extent that they occur, the face becomes narrower and higher. Overall cranial vault size has increased, but shape changes are greater than size changes. The magnitude of secular change in vault height exceeds that for long bones over a comparable time period, but follows a similar course, which suggests that vault height and bone length respond to the same forces. Changes in vault dimensions must occur by early childhood because of the early development of the vault. Am. J. Hum. Biol. 12:327-338, 2000. Copyright 2000 Wiley-Liss, Inc.

Anthropometric variation among the Sioux and the Assiniboine.

Historically, the Assiniboine are thought to have split from the Yanktonai Sioux some time in the early 17th century, but this view has been challenged by some linguists, archeologists, and skeletal biologists. Our purpose here is to examine the population structure of the Sioux and the Assiniboine, as reflected in 6 head and 6 body anthropometric dimensions, and to investigate the hypothesis that the Assiniboine diverged relatively recently from the Yanktonai Sioux. For both males and females there is an overall significant division effect, and the FST value indicates a fair amount of differentiation among these closely related groups. The Assiniboine are clearly distinct from all 3 Sioux divisions. The Assiniboine also exhibit a higher within-group phenotypic variance than expected, indicating that their differentiation is due to time and gene flow from outside groups. Among the Sioux divisions the Santee and Yankton-Yanktonai are the most similar, especially in head and face dimensions. The results of this study do not support the historical account of Assiniboine origins. The high degree of differentiation between the Yanktonai and Assiniboine suggests a much more distant split between the Assiniboine and the Sioux than has been traditionally put forth.

Secular change in long bone length and proportion in the United States, 1800-1970.

We examine secular change in long bone lengths and allometry of Americans dating from the mid-19th century to the 1970s. Skeletal samples were derived from the Huntington Collection, Terry Collection, World War II casualties, and the Forensic Anthropology Data Bank. Regression of bone length on year of birth allowed evaluation of the secular change in bone length. Size was computed as the geometric mean of all bone lengths, and shape as the ratio of each bone to size. These variables were then regressed on year of birth, allowing evaluation of allometric secular change. The results revealed a pattern of change that can be summarized as follows: male secular change is stronger than female, lower limb bone secular change is more pronounced than upper limb bone change, and distal bones change more than proximal bones, particularly in the lower limb. In males, white changes are uniformly higher than black but these differences do not rise to the level of statistical significance. Environmental forces, such as nutrition and disease, are the usual causes of secular changes in overall size. This paper shows that long bone proportions also respond to these same environmental factors. Moreover, the changes in body proportion are likely to be due to allometric consequences of growth changes that occur early in life. Am J Phys Anthropol 110:57-67, 1999.

Cranial thickness in American females and males.

To date, numerous studies have examined the range of cranial thickness variation in modern humans. The purpose of this investigation is to present a new method that would be easier to replicate, and to examine sex and age variation in cranial thickness in a white sample. The method consists of excising four cranial segments from the frontal and parietal regions. The sample consists of 165 specimens collected at autopsy and 15 calvarial specimens. An increase in cranial thickness with age was observed. The results suggest that cranial thickness is not sexually dimorphic outside the onset of hyperostosis frontalis interna (HFI).

Variation among European populations in summary finger ridge-count variables.

The magnitude of ridge-count variation and its spatial and linguistic patterning was examined using 82 male and 75 female samples from Europe. Variables were summary measures: sum of radial counts (radial) sum of ulnar counts (ulnar) and sum of larger counts (total ridge-count or TRC). Dermatoglyphic parameters were compared with those derived from classic nuclear gene markers. Fst values computed from ridge-counts range between 0.016 and 0.025, relatively high when compared to classical genetic polymorphism. Ridge-count distances show significant correlation with geographic distances but not with linguistic distances. Ridge-count distances show even higher correlation with blood marker distances, suggesting that, like blood polymorphisms, ridge-counts were strongly influenced by demic expansion of Neolithic farmers. The most differentiated populations in Europe are those of the North Atlantic and North Sea region, especially the Orcadians and Faroe Islanders. Certain Finnic speakers such as Lapps and Udmurts are also strongly differentiated. These same populations are frequent outliers in genetic analyses.

Dermatoglyphic variation in Europe.

We describe the geographic variation patterns of 236 dermatoglyphic variables (118 for each sex) for 74 samples in Europe. Using principal components analysis and rotating to simple structure, we simplified these patterns to the first 20 axes, representing 74.2% of covariation. We then used heterogeneity tests, interpolated surfaces, one-dimensional and directional correlograms, and distances between correlograms to analyze the factor scores of these 20 axes. We also ordinated the 74 localities. The data are remarkable for showing little spatial autocorrelation, despite significant heterogeneity among localities. Only three factor axes exhibit consistently significant correlograms, indicating that there are few spatial patterns in the original variables in Europe. Almost all correlations between pairs of variables occur within serially homologous character sets and are thus developmentally determined. There is some support for demic diffusion from the southeast in finger patterns and ridge counts. We compare these results to those of previous studies and note that Lapps and Icelanders are outliers with respect to both genetics and finger tip variables, whereas Tatars are outliers with respect to craniometrics and dermatoglyphics.

The measure and mismeasure of the tibia: implications for stature estimation.

Trotter and Gleser's stature estimation formulae, based on skeletons of the Terry collection and on WWII casualties, have been widely used in forensic work. Our work with the Terry and WWII data yielded tibia lengths too short compared to other data sets. Using Trotter's original measurements, we discovered that she consistently mismeasured the tibia. Contrary to standard practice and her own definitions, she omitted the malleolus from the measurement. Trotter's measurements of the tibia are 10 to 12 mm shorter than they should have been, resulting in stature estimations averaging 2.5 to 3.0 cm too great when the formulae are used with properly measured tibia. We also examined tibia lengths of Korean War casualties, which were measured by technicians rather than by Trotter. Korean tibia measurements are also too short, but by a smaller amount than Terry and WWII. Since the Korean tibia are unavailable for restudy, it is unclear how they were measured. Estimation of stature from Trotter and Gleser's tibia formulae is to be avoided if possible. If necessary, the 1952 formulae could be used with tibia measured in the same manner that Trotter measured, excluding the malleolus.

Allometric secular change in the long bones from the 1800s to the present.

Allometric secular changes in the six long limb bones for White and Black males from the mid 1800s to the present are examined. Long bone lengths are available from the Terry collection and WWII casualties. We conducted two types of analysis to reveal secular changes. First, allometry scaling coefficients were derived by regressing log bone length onto log stature. These showed that the femur, tibia and fibula were positively allometric with stature, while the humerus, radius and ulna were isometric. The lower limb bones were more positively allometric in the WWII sample than in the Terry sample. Second, secular changes in length of femur and tibia and in the tibia/femur ratio were evaluated, using modern forensic cases in addition to the Terry and WWII samples. This analysis shows that secular increase in lower limb bone length is accompanied by relatively longer tibiae. Secular changes in proportion may render stature formulae based on nineteenth century samples, such as the Terry collection, inappropriate for modern forensic cases. The positive allometry of the lower limb bones argues against using simple femur/stature ratio, which assumes constant proportionality, as an alternative to regression equations.

Franz Boas and Native American biological variability.

The contributions to physical anthropology with which Franz Boas is usually credited are in the areas of growth, plasticity of head and body form, and biometric genetics. Such a listing of Boas's contributions overlooks the tremendous amount of research he did with biological variability of Native American populations. The rediscovery of his anthropometric data documents the tremendous investment in time, money, and effort Boas devoted to the topic and provides the opportunity to rediscover his insights into a subject that is of continuing interest. The design of his massive anthropometric survey of native North Americans reveals a concern for population analyses and a rejection of the typological framework of the time. If Boas's ideas had been adopted at the turn of the century, the development of physical anthropology in America might have been much different.

Population structure of Algonquian speakers.

Speakers of Algonquian languages are widely dispersed geographically but are homogeneous linguistically. We examine anthropometric differentiation among Algonquian-speaking populations distributed from New Brunswick to Montana. Head and face measurements and body measurements were analyzed separately in an attempt to address the effect of phenotypic plasticity on relationships. The head and face and body dimensions yield somewhat different pictures of relationships. From the head and face data an east to west geographic pattern can be discerned. The principal feature of the body measurements is the distinctiveness of the Ojibwa located northwest of Lake Superior. The formal correlation between the two sets of measurements is low and not significant. Only the head and face dimensions correlate significantly with geographic distances. Language distances do not correlate with anthropometric distances. The set of populations is also more strongly differentiated with respect to body measurements than to head and face measurements. We interpret this as reflecting phenotypic plasticity and possibly greater interobserver variation.

Population relationships of Lapps as reflected by quantitative dermatoglyphics.

Relationships and divergence among five Lapp samples were assessed using finger and palm interdigital ridge counts. Lapp relationships to other Uralic speakers were also assessed. Multivariate minimum FST values expressing differentiation among Lapps are 0.012. These values are higher than those for most European populations and show the importance of isolation and genetic drift in Lapp populations. Skolt Lapps and Lapps of the Kola Peninsula are generally more similar to each other and are differentiated from Mountain and Fisher Lapps. When Lapps are placed within the context of Uralic speakers in general, they show a marked affinity for the Finnic speakers and are differentiated from the Samoyedic speakers of Siberia. The ridge counts support the hypothesis of a European origin for the Lapps.

Directional and fluctuating asymmetry in the palmar interdigital ridge-counts.

Directional and fluctuating asymmetry of the palmar interdigital ridge-counts (c-d, b-c and a-b) was evaluated using a sample of 1186 male and 1042 female Germans. The c-d and b-c ridge-counts show higher right side values while the a-b count shows a higher left side value. Sex differences in asymmetry are significant, females exhibiting larger left values than males for all three counts. Directional asymmetries of the different areas exhibit weak negative correlations. Fluctuating asymmetry (magnitude of L-R) is highest for the c-d count, followed by the a-b. Both c-d and a-b ridge-counts exhibit a significant quadratic relationship between magnitude of L-R and R+L, but b-c does not. The quadratic relationship shows that individuals with extreme phenotypes are more asymmetrical than those closer to the mean. This in turn may be interpreted to mean that fluctuating asymmetry is a reflection of developmental stability.

Dermatoglyphic variation among Finno-Ugric speaking populations: methodological alternatives.

Utilization of dermatoglyphics for population studies is apparently increasing, but methods vary widely among investigators. We investigate how different types of dermatoglyphic data can affect estimates of biological distance among Finno-Ugric speaking populations. Dermatoglyphic distances were calculated using the following categories of traits: 1) Finger ridge-counts (radial and ulnar count for each digit), 2) finger ridge-counts (largest count for each digit), 3) finger pattern types, 4) palm ridge-counts, 5) palm patterns, and 6) main-line terminations. In addition, we compare our distances with those of Heet, which rely heavily on summary characters. Distances are evaluated by comparing them to each other and to language and geographic distances. There is considerable variation in the pattern of relationships resulting from the different variable sets. Finger variables, whether ridge-counts or pattern classifications, agree well with each other. Palm patterns, main-lines, and finger variables show moderate agreement with each other, while palm ridge-counts agree poorly with all variable sets except main-lines. Heet's distances agree poorly with all other dermatoglyphic distances. Finger patterns and main-lines are most closely related to language distances, after controlling for geography, while correlations with geography generally disappear after controlling for language. Heet's distances have weak associations with language and geography. Finger variables and palm main-lines yield results which agree best with historical relationships among Finno-Ugric populations. Our results make it very clear that utilization of dermatoglyphics in population studies requires careful consideration of methods, and that summary measures of quantitative or qualitative data should be used with caution.

Modification of the Trotter and Gleser female stature estimation formulae.

Stature-estimation formulae in common use are those of Trotter and Gleser. Their formulae for females are based on Terry collection skeletons. These skeletons are from people who died in the early 1990s. Because there has been considerable change in body size since then, it is possible that the Trotter and Gleser formulae are inappropriate for modern forensic-science application. The Trotter and Gleser female formulae are tested using data from the Forensic Data Bank at the University of Tennessee. For whites, the femur and tibia yield stature estimates differing from one another by about 3 cm. Using femur and tibia lengths from modern forensic cases and modern height data from anthropometric surveys, new regression intercepts are calculated for Trotter and Gleser's female formulae. The new intercepts improve the performance of the formulae on modern individuals. The Trotter and Gleser formulae for black females require no adjustment. Both blacks and whites have experienced a secular increase in bone length, but whites have experienced a change in proportions as well.