Dermatoglyphic distances and different linguistic groups in Sardinia

By means of Penrose's C _H ² , a matrix of dermatoglyphic distances was calculated from several palmar characteristics of 1831 males belonging to different Sardinian linguistic groups. Then, by means of cluster analysis, a dendrogram was constructed and compared with a diagram of the affinities among the linguistic groups. This comparison shows a good congruency between the dendrogram structure and the diagram of linguistic affinities. Supported by M.P.I. 60%, 1983.     

Genetic basis of a-b,b-c and c-d ridge counts on human soles

The mechanism of inheritance of ridge count of plantar inter-digital areas has been studied among Brahmans of Sagar town of Central India. The correlation coefficient between ridge counts in various family relationships lend support to the concept of an additive genetic model.     

Genetic heterogeneity among the Negroid and Arab tribes of the Sudan

Genetic distance analysis was carried out among seven tribes of the Sudan comprising three Negroid (Nuba, Fur, and Nilotes) and four Arab tribes (Beja, Gaalin, Hawazma, and Messeria) on the basis of six polymorphic loci (ABO and Rhesus blood groups; haemoglobin and red cell glucose-6-phosphate dehydrogenase; serum haptoglobin and transferrin polymorphisms) controlling 21 alleles and compared with the Arab and Negroid populations in neighbouring countries. The Nuba and Nilotes have been found to have Negroid genetic characteristics, while the Fur are intermediate between the Arabs and Negroids. The Beja and Gaalin tribes have more pronounced Arab genetic characteristics than the Hawazma and Messeria, who have a great deal of Negroid admixture.     

Isolation by distance on the Island of Korcula: correlation analysis of distance measures

Within the framework of holistic anthropological investigations of the rural populations on the Island of Korcula, 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.     

Genetic composition of Chilean aboriginal populations: HLA and other genetic marker variation

Phenotypes and gene frequencies for eight genetic systems are presented for five Chilean Indian tribes. Results agree with the pattern expected for Andean Indians. Genetic distances and dendrograms were obtained separately for HLA and traditional genetic markers. The similarity of both is noteworthy. Linguistic distances exhibit a correlation with genetic distances based on traditional markers. © 1996 Wiley-Liss, Inc.     

A method for subclassifying the interdigital patterns: a comparative study of the palmar configurations

A method for subtyping the interdigital patterns is introduced, which is based upon the direction of the main line terminations as well as the presence of accessory triradii. The palmar patterns of several population samples from our files representing the Caucasians, Negroes, Miconesians and New Guinean groups are evaluted in terms of the introduced calssification and the results demonstrate a number of differences between the major racial groups. In additin, the thenar/I and hypothenar patterns are subtyped according to the classifications of Cummins and Midlo. These data also indicate the inadequacy of the general open/arch, vestige, loop, whorl identification of the plamar patterns. It is hoped that more data will be studied along these lines for establishment of more accurate frequencies among the various racial groups.     

Genetic analysis of ewe productivity traits in Moghani sheep

Genetic and environmental (co)variance components for productivity traits in Moghani sheep were estimated using data from 1344 ewes. The data were collected in the Jafarabad breeding station, north-east of Iran, during a 13-year period (1995-2008). The studied traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB) and total litter weight at weaning (TLWW). A model including direct additive genetic effects as well as permanent environmental effects related to repeated records of ewe was the most appropriate model for all the studied traits. Genetic parameters were estimated applying restricted maximum likelihood (REML) procedure. Direct heritability estimate for LSB, LSW, LMWLB, LMWLW, TLWB and TLWW were 0.11, 0.02, 0.15, 0.07, 0.07 and 0.06, respectively. Corresponding values for repeatability estimates were 0.16, 0.19, 0.18, 0.11, 0.13 and 0.09. Genetic correlations between the studied traits ranged from −0.99 for LSB-LMWLB and LSW-LMWLB to 0.99 for LSB-TLWB. Phenotypic and environmental correlation estimates were generally lower than those of genetic ones. Estimates of permanent environmental correlation among traits were positive and medium to high. Although low direct heritabilities were estimated for the reproductive traits, as these traits are of interest then they should be included in a breeding program.     

Estimation of heritability by offspring-parent regression when observations do not have a common mean

Summary Offspring-parent regression is a simple method for estimating heritability. This method yields unbiased estimates even when parents are selected. The usual model in offspring-parent regression assumes that observations have the same mean. This assumption, however, is not met in many situations. A method for estimating heritability by offspring-parent regression when observations do not have a common mean is presented. The estimator is distributed as a multiple of a t random variable centered at its parametric value and is unbiased even when the parents are selected. When observations have a common mean, the method reduces to the usual regression estimator.     

Estimation of heritability and genetic trend in populations at a physiological limit

Summary Limits on physiological processes, though perhaps unknown, must exist. The reported simulations evaluate the effect of a physiological limit on the estimation of genetic parameters and genetic progress. Simulation experiments reveal no change in the estimate of heritability, even for limits as restrictive as 1.5 phenotypic standard deviations above the population mean. However, estimates of additive genetic and environmental variance shrink as limits on performance increase in severity. Simulated physiological limits do not affect the rate of genetic progress. However, absolute measures of estimated genetic change are less than those predicted by response equations.     

Inequality constrained estimation of genetic parameters

Summary A method is presented for computing estimates of genetic parameters under linear inequality constraints such that solutions are within theoretical limits. The method produces biased estimators, yet a small scale numerical study, also presented, shows that the inequality constrained estimators have a small mean squared error of prediction than the best of unbiased estimators. The increase in efficiency of estimation is particularly useful for traits where heritability is near the boundary values of zero or one.     

Comparison of RFLP and morphological distances between maize Zea mays L. inbred lines. Consequences for germplasm protection purposes

 A total of 145 maize inbred lines, representative of material released in France, were differentiated using RFLP markers and a set of discriminant morphological traits in order to evaluate the use of molecular markers for large-scale germplasm diversity analysis and determination of distinctness. Several criteria are proposed with respect to choice of probes, which should give reliable results for routine studies and have a known single-locus genetic determinism to avoid redundancy. A method is proposed by which to incorporate the data from different restriction enzymes obtained with the same probe. The precision of the estimation of the genetic distance is given. The relationship between molecular and morphological distances appears to be triangular, molecular divergence behaving as a limiting factor for morphological divergence. This suggested a scheme for incorporating molecular markers in studies of distinctness. Received: 20 August 1996 / Accepted: 20 December 1996     

Genetic data on Alghero population (Sardinia): Contrast between biological and cultural evidence

Data on 20 genetic polymorphisms (61 alleles) in the Algehero population on the northwestern coast of Sardinia are presented and discussed in relation to its linguistic peculiarity inside the island. Since the Aragonese (Spain) conquest of Sardinia in the 13th century, the Catalan language, the same as that spoken in Northeastern Spain and certain districts of Southern France, has been used in Alghero even until today. Analysis for heterogeneity of gene frequency distributions indicates that the genetic information obtained on Alghero is adequate to discriminate Sardinians from other neighbouring populations. Genetic variation between populations measured through genetic distances and principal-component analysis shows that the present-day population of Alghero is much closer genetically to Sardinians than to Catalonians. Our genetic results do not support any interpretation of the linguistic affinities between Alghero and Catalonia at present as indicative of biological kinship. © 1994 Wiley-Liss, Inc.     

Altitude,language, and class I HLA allele frequencies in Papua New Guinea

Class I HLA gene frequencies show considerable variation over short geographical distances in Papua New Guinea. Hypotheses to account for this invoke natural selection, population structure, the pattern of population movement, or past demographic changes. To determine the role of the various factors in shaping this distribution, we have studied correlations between HLA-based genetic distances, geographical distances, altitude, and linguistic differences in Papua New Guinea. Linguistic differences at the family or stock level within the Trans-New Guinea Phylum generally correspond to genetic differences. However, on the basis of their HLA gene frequencies, speakers of Austronesian (AN) languages do not form a distinct group of populations. Linguistic variation and spatial autocorrelation do not fully account for the altitudinal cline differences noted in gene frequencies, particularly at the HLA-A locus. We propose that the distribution of HLA gene frequencies in Papua New Guinea is partially under the control of selection operating differentially along the altitude gradient. © 1994 Wiley-Liss, Inc.     

Genetic variation in basic density and modulus of elasticity of coastal Douglas-fir

Douglas-fir trees from 39 open-pollinated families at four test locations were assessed to estimate heritability of modulus of elasticity (MOE) and basic density. After trees were felled, sound velocity was measured on 4-m logs with the Director HM200. Disks were taken to estimate dry and green wood density; dynamic MOE was estimated as green density × (sound velocity)². Heritability estimates of MOE (across-site h ²=0.55) were larger than those for total height (0.15) and diameter at breast height (DBH; 0.29), and similar to those for density (0.59). Negative genetic correlations were found for MOE with height (r _A=−0.30) and DBH (r _A=−0.51), and were similar to those found for density with height (r _A=−0.52) and DBH (r _A=−0.57). The partial correlations of height with MOE and density, while holding DBH constant, were positive, implying that the observed negative correlations between height and the wood properties were a function of the high positive correlation between height and DBH and the strong negative correlations between DBH and the wood properties. Taper [DBH/(height−1.4)] was found to be negatively associated with MOE. Selection for MOE may produce greater gains than selection for density because MOE had a larger coefficient of additive variation (9.6%) than density (5.1%). Conversely, selection for growth may have a more negative impact on MOE than density because of the greater genetic variation associated with MOE. Family mean correlations of the wood quality traits with stem form and crown health were mostly nonsignificant.     

The importance of base composition in the correct assessment of genetic distance

Through a simple computer simulation, we provide clear evidence that the base composition of nucleotide sequences should be taken into account to obtain accurate estimates of the genetic distances between homologous nucleotide sequences. We tested several stochastic models and demonstrated clearly that the inferred estimates of the number of substitutions are strongly dependent on the a priori conditions superimposed in the model, i.e., equiprobability in base composition and/or transition transversion ratio. In general, the more a priori assumptions there are, the more inaccurate the results. Whereas, rather accurate estimates are obtained with stochastic methods, which take into account base composition and do not superimpose unverified a priori conditions. Correspondence to: G. Pesole