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Biomedical subjects

R L Jantz

Publications and source records attributed to R L Jantz.

At least 19 recordsLinked to original sources

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.

Analysis of Variance

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.

Anthropology, Physical

Estimation of stature from metacarpal lengths.

Formulae for the estimation of stature from metacarpal lengths are presented. Two samples of metacarpal specimens were employed in the analysis: one of 212 individuals from the Terry Collection, and one of 55 modern males, all of whom had measured statures. One measurement, the midline length, was taken on each metacarpal. Stature was regressed on the basis of the metacarpal length to derive equations for the Terry Collection individuals. Comparisons between the Terry Collection males and the modern sample showed the latter to have longer metacarpals and greater statures. The Terry equations were tested using the modern male sample. In spite of the differences noted, the Terry equations perform acceptably on modern individuals. The performance was slightly better for whites than for blacks. Since the female equations were not tested, they should be employed with greater caution.

Black People

Variation among North Amerindians: analysis of Boas's anthropometric data.

In the late nineteenth century Franz Boas was responsible for assembling anthropometric data from North Amerindians. Approximately 15,000 subjects were measured, but the data have never been systematically analyzed. Here we describe our efforts to develop a computerized database from Boas's data and present the first systematic analysis of these data. In addition to a general analysis of North Amerindian anthropometric variation, we also present a more detailed analysis of anthropometric variation among tribes located in the American Northwest. In the general analysis we find that anthropometric variation is strongly patterned along geographic lines. We examine geographic and language patterning by grouping tribes by culture area and language phylum. Both have high explanatory power, culture area being the higher. The Northwest analysis shows that both language and geographic location are important in explaining anthropometric variation.

Anthropology, Physical

Maxillary suture obliteration: a visual method for estimating skeletal age.

The purpose of this study was to develop a method of estimating the age of an individual based on obliteration of the four maxillary (palatal) sutures. A sample of 186 individuals of known age, race, and sex were examined. It was found that males of both races (black and white) exhibit more suture obliteration than females at the same age. During the early adult years, maxillary suture obliteration progresses at nearly the same rate in both sexes; however, the age of old individuals may be greatly overestimated using this method. Although this method cannot be used for exact estimates of individual age, it is valuable in establishing the age range, sorting commingled remains, and estimating skeletal age when only the maxilla is present.

Adolescent

Statistical assessment of population variability: a methodological approach.

We have implemented a multivariate statistical methodology to assess the degree and pattern of cranial variability in skeletal samples. Specifically, the method is designed to test whether variability in a skeletal sample exceeds "normal within-group variability" defined in the present instance as variability present among crania from a cemetery associated with a village. It involves comparing a covariance matrix derived from a sample of unknown composition to one representing "normal within-group variability." The method has been applied to two Plains Indian craniometric samples. The Leavenworth site (39CO9) represents the remnants of previously autonomous Arikara Indian villages devastated by epidemic diseases in the late 1700s. The Bad River 2 Phase is an archaeological designation grouping together closely related sites in the Bad-Cheyenne region of South Dakota dating from 1740-1795 AD. We were able to show substantial heterogeneity among crania from Leavenworth. District burial areas at Leavenworth account for some of the heterogeneity, supporting the notion that they represent an attempt to maintain former social distinctions. We were unable to differentiate among sites within the Bad River 2 Phase, suggesting that it is a valid biological unit.

Analysis of Variance

Palm and sole interdigital ridge-count correlations.

Correlations among the twelve palm and sole interdigital ridge-counts were calculated for samples of Europeans of German, Austrian, Finnish and Polish ancestry, for Bantu speaking Black Africans from Angola and the Republic of South Africa, for Japanese and Tibetans and for Indians and Coloureds from the Republic of South Africa. Canonical correlation and factor analyses were used to discern patterning in the correlations. Generally, within palm and within sole correlations are stronger than palm-sole correlations. However, the results show an unequivocal positive relationship between palm and sole ridge-counts. A consistent feature was a stronger relationship of palm c-d counts to sole a-b counts. We suggest that this pattern of correlation may reflect early morphogenetic pattern formation prior to commitment of cells to hands and feet.

Africa

Stature estimation from fragmentary femora: a revision of the Steele method.

The skeletal remains presented to forensic anthropologists are often fragmentary. Previously described methods of estimating stature from segments of long bones have not proved satisfactory because of the difficulty involved in identifying the precise anatomical landmarks by which they are defined. This study represents an assessment of the feasibility of stature estimation from fragmentary femora. A sample of 200 males and females, blacks and whites (total sample = 800), was obtained from the Terry Collection. New regression equations for the estimation of maximum femur length and stature from three well-defined and easy-to-measure segments of the femur are presented. This technique represents an improvement over methods currently in use for estimating stature from femur fragments; the location of the anatomical landmarks and the accuracy of the prediction are enhanced. The applicability of these formulae to a modern forensic sample is addressed with regard to secular trends in stature increase and changes in body segment proportions.

Anthropology, Physical

Finger and palmar dermatoglyphics of a Yoruba (Nigeria) sample.

Finger and palm prints of 126 male and 55 female Yoruba are reported using both quantitative and qualitative procedures. In general, the Yoruba fit into established geographical gradients for sub-saharan African populations. Whorl frequencies on the digits are relatively low, as is the frequency of palmar patterning. Finger ridge-counts, those of males in particular are high by African standards, and much higher than the previously reported data from Nigeria. Due to the lack of data on patterns of geographic variation in total finger ridge-count, little can be made of these findings at present.

Dermatoglyphics

Sex and race differences in finger ridge-count correlations.

Correlations between ridge-counts on the ten fingers were compared by race and sex in 11 samples representing Negroes and Caucasians: five from subsaharan Africa, one American Black, three European, one American White and one from India. The samples of European ancestry showed no consistent sex difference in mean correlation, although female American Whites significantly exceeded males. In three of the six Negro samples and in the Parsis of India males showed significantly higher average correlations than females. The pattern of sex and race differences suggests that the sex chromosomes, particularly the Y chromosome, play a role in dermal ridge development.

Black People

Factor analysis of finger ridge-counts in Blacks and Whites.

Finger ridge-counts of an American White, American Black and an African Black sample were subjected to factor analysis. The analysis was carried out using correlation matrices computed from 10-ridge counts, each finger being represented by its largest count, and from 20 ridge-counts, using both radial and ulnar counts for each finger. The 20 count analysis was much more informative, demonstrating the relative independence of the radial and ulnar sides of the fingers. Moreover, the radial and ulnar counts themselves generally resulted in two factors reflecting counts on the ulnar digits and the median digits. The independence of the thumb was also demonstrated. There was considerable intersample consistency, although some evidence of sex and race variation was observed.

Black People

Inbreeding, marital movement, and genetic isolation of a rural Appalachian population.

Genealogical, marital, birthplace and age-at-marriage data were collected on a random sample of 275 reproducing couples from the population of a rural Appalachian county in north-eastern Tennessee. Genealogies covering the three extant generations provided the data for a surname isonymy analysis to determine the amount of inbreeding prevalent, while the marital, birthplace and age at marriage data were used to ascertain the components of marital movement, i.e., marital distance, orientation of marital movement, spatial exogamy, and "diffusion". The effective breeding population and effective immigration rate were calculated for the county population and these in turn were used to compute the coefficient of breeding isolation for the currently reproduction population. Our conclusions agree with those of an earlier genetic and demographic study on one segment of the same population. The more extensive demographic analysis illustrates the value of such studies as this for providing background for interpretations of genetic variation.

Consanguinity

The relation between total finger ridge-count and variability of counts from finger: genetic implications of racial variation.

The measure of ridge-count diversity, S/square root 10, was computed for a sample of American Whites, American Blacks and African Blacks, and the regression of S/square root 10 on total ridge-count was determined for each group. The shapes of the regression lines differed considerably. The American White curve was very similar to that obtained by Holt in an English sample, while the two Negro curves generally showed lower lower S/square root 10 values for ridge-counts over 80. The American Negro curve was found to behave like a mixture of the White and African Negro curve to a degree approximating to the fraction of White genes in their gene pool. Holt's parent-child data are used to construct a simple test of the hypothesis that that S/square root 10 reflects zygosity in total ridge-count genotypes. The preliminary results support this hypothesis.

Black or African American

Population variation in asymmetry and diversity from finger to finger for digital ridge-count.

Population variation in ridge-count asymmetry and diversity from finger to finger has received scant attention in dermatoglyphic studies. Asymmetry, in particular, has generally been attributed to environmental effects operating during the formation of dermal ridges. Examination of samples from several groups of diverse racial background revealed the existence of considerable population variation with respect to finger ridge-count asymmetry and diversity from finger to finger. Patterning along population lines suggests a genetic rather than environmental basis for such variation. The genetic mechanisms responsible for ridge-counts may also mediate asymmetry and diversity, or the degree of developmental stabiltiy in different populations may itself be under genetic control.

Africa