Allozyme variation in four populations of African whitebacked vultures (Gyps africanus) and phylogenetic relationships between four vulture species from southern Africa

Genetic variation detected by protein electrophoresis at 41 presumptive gene loci was assayed in four populations of Gyps africanus and compared to values previously obtained for Gyps coprotheres. Values calculated for percentage of polymorphic loci (P=34.15%, 0.99 criterion) and average heterozygosity (&Hmacr;=0.108, +/-0.032) in G. africanus, confirm low levels of genetic variation as reported for G. coprotheres. Allele frequency data, assessed at 19 loci, were obtained to evaluate genetic differentiation among four vulture species. Six (31.58%) of the 19 shared loci were polymorphic. Values of 1.26 (+/-0.1), 26.32% and 0.076 (+/-0.047) for G. africanus, 1.21 (+/-0.1), 21.05% and 0.097 (+/-0.045) for Torgos tracheliotus, 1.11 (+/-0.7), 21.05% and 0.053 (+/-0.053) for Neophron percnopterus and 1.05 (+/-0.5), 5.26% and 0.044 (+/-0.047) for G. coprotheres were obtained for the mean number of alleles per locus, P and &Hmacr;, respectively. An average between-population fixation index (F(ST)) value of 0.322 was obtained, which is indicative of significant (P<0.01) differentiation between the four accipitrid species studied. Considerable concordance was obtained between dendograms produced from different analyses, pointing to the distinctiveness of N. percnopterus, which has evolved along a separate lineage as G. africanus, G. coprotheres and T. tracheliotus. Along the latter lineage G. africanus is clustered together with G. coprotheres which is consistent with the morphological similarities of these species.     

Diachronic variation in cranial thickness of Near Eastern populations

Cephalometric radiographs were taken of 111 skulls of skeletal remains of populations living in Israel and Jordan during the last 12,000 years. From these radiographs, skull length and height, and cranial thickness were measured. For each sex and period, high correlations were found between cranial thickness at vertex, bregma, and lambda. Cranial thickness at nasion was correlated with sinus width but not sinus height. All measurements were correlated with skull length but not skull breadth. Using multivariate analysis, no significant differences in cranial thickness were found between the sexes. Significant diachronic trends were found in lambda and sinus width, and they were independent of variation in skull length.     

Carpal fusions in children of four South African populations

The incidence of carpal fusions was determined from radiographs of both hands of 2,250 Pretoria schoolchildren aged 72 to 191 months. The group included White, Negro, Coloured and Indian subjects. Of the many possible varieties of carpal fusion, only lunato-triquetral fusion and capitate-hamate fusion were encountered. No examples of lunato-triquetral fusion were encountered in children less than ten years of age. In Pretoria Negroes aged 10 to 15 years, the incidence of lunato-triquetral synostosis is 4.57%, while Pretoria Coloureds show an incidence of 1.51%. This type of fusion was not noted in the White or Indian populations. Two examples of capitate-hamate synostosis were encountered in Pretoria Negroes. The available evidence suggests that these two varieties of carpal fusion may be added to the list of discrete traits varying in frequency from population to population and probably reflecting different underlying gene frequencies. No significant sex difference in incidence of lunato-triquetral fusion was noted in the present study. Lunato-triquetral fusion is about twice as commonly bilateral as unilateral in occurrence.     

Gene flow and variation in stature and craniofacial dimensions among indigenous populations of southern Mexico, Guatemala, and Honduras

Populations with histories of outbreeding tend to be taller even in the face of seemingly unchanged health and nutritional circumstances, while inbreeding generally results in a negative correlation between body dimensions and level of inbreeding. Populations that have experienced a positive secular trend in stature and maturation typically have histories of higher outbreeding rates in combination with improved nutritional, health, and economic conditions, suggesting a genetic-environment interaction. In general, Middle American Indians have not experienced a secular trend in stature, nor a substantial increase in their standard of living, but they have experienced varying degrees of admixture with Spanish and African populations since the Spanish Conquest. The relationship between estimated gene flow and variation in several anthropometric dimensions is thus considered in indigenous Mesoamerican populations. Available data on height, sitting height, craniofacial dimensions, and admixture rate of Indian populations from southern Mexico, Guatemala, and Honduras were assembled from the literature. The population mean data on 3,371 adults from 23 populations for males and 18 for females were analyzed by regression with anthropometry as the dependent variable, and log10 of admixture as the independent variable. Admixture was less than or equal to 28.9% in this study and is suggestive of a primarily traditional Indian cultural and economic base. The results suggest that populations with higher admixture tend to be taller, and that the increase in stature is due to greater subischial length in both sexes. A decrease in nasion-menton height, and an increase in nasal breadth, nasal height, and the nasal index is suggested for the dimensions of the craniofacial complex.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microevolution in prehistoric Andean populations: Chronologic nonmetrical cranial variation in northern Chile

Multivariate distance statistics were computed from 14 nonmetrical cranial variables among five prehistoric samples representing steps in the microevolutionary history of a coastal population in northern Chile. Roughly 70% of nonmetrical cranial variation was found to be explained by chronologic distance covering a period of 6,500 years. This estimate is similar to a previous one derived from craniometric data. Implications of these findings are briefly discussed.     

中国对虾（Penaeus chinensis）4个种群的同工酶遗传变异

采用水平淀粉凝胶电泳技术分析了中国对虾（Penaeuschinensis）黄渤海沿岸种群（YP）、朝鲜半岛西海岸种群（KP）和2个养殖种群（CP1和CP2）的同工酶遗传变异水平。每个种群随机选取50尾中国对虾进行同工酶检测。在所分析的12种同工酶编码的20个基因位点中,有4个是多态位点。4个种群的多态位点比例（P0.99）分别为15%、20%、10%和20%。种群平均杂合度（观测值）（Ho）分别为0.014±0.007、0.020±0.010、0.010±0.007和0.033±0.017。4个种群的位点有效等位基因数（Ne）分别为1.015±0.008、1.023±0.011、1.011±0.007和1.042±0.022。杂合子平衡偏离指数（D）分别为+0.037、-0.030、-0.098和-0.030。2个地理种群（YP和KP）的遗传相似性系数（I）和遗传距离（D     

枕骨三维形态在现生人群间的变异

与面颅、脑颅和颅底不同,枕骨与人群间遗传信息的关系不明确且研究较少。传统形态测量方法对枕骨的研究难以全面反映枕骨的形态信息。为更加精细地探究枕骨形态与人群的关系,本文以亚洲、非洲和欧洲地区的103例现生男性头骨为研究对象,通过三维几何形态测量和多元统计分析的方法对枕骨三维形态和异速生长模式在人群间的差异进行了研究。研究结果表明,枕骨的大小和形状在现生人群中具有显著差异,然而这种差异并不足以区分不同人群。现代人枕骨的三维形态具有较大的变异,主要表现在枕外隆凸点的突出程度、上下相对位置以及枕平面与项平面的比例,其次表现在星点位置在前后、内外以及上下方向上的变化,斜坡的倾角变化等方面。异速生长的分析表明,不同人群中存在不同的异速生长模式,但是非洲和欧洲人群也存在相似的趋势。本研究认为枕骨三维形态在反映人群间遗传关系上作用较小,支持枕骨形态可能更多受到功能和环境等因素的影响。     

mtDNA and Y-chromosome polymorphisms in four Native American populations from southern Mexico.

mtDNA sequence variation was examined in 60 Native Americans (Mixtecs from the Alta, Mixtecs from the Baja, Valley Zapotecs, and Highland Mixe) from southern Mexico by PCR amplification and high-resolution restriction endonuclease analysis. Four groups of mtDNA haplotypes (haplogroups A, B, C, and D) characterize Amerind populations, but only three (haplogroups A, B, and C) were observed in these Mexican populations. The comparison of their mtDNA variation with that observed in other populations from Mexico and Central America permits a clear distinction among the different Middle American tribes and raises questions about some of their linguistic affiliations. The males of these population samples were also analyzed for Y-chromosome RFLPs with the probes 49a, 49f, and 12f2. This analysis suggests that certain Y-chromosome haplotypes were brought from Asia during the colonization of the Americas, and a differential gene flow was introduced into Native American populations from European males and females.     

Population structure, genetic variation and morphological diversity in indigenous sheep of Ethiopia

We investigated genetic and morphological diversity and population structure of 14 traditional sheep populations originating from four ecological zones in Ethiopia (sub-alpine, wet highland, sub-humid lowland and arid lowland). All animals (n = 672) were genotyped for 17 microsatellite markers and scored for 12 morphological characters. The sheep were initially classified as fat-tailed (11 populations), thin-tailed (one population) and fat-rumped sheep (two populations). These classifications are thought to correspond to three consecutive introduction events of sheep from the Near-East into East Africa. For the 14 populations, allelic richness ranged from 5.87 to 7.51 and expected heterozygosity (H(E)) from 0.66 to 0.75. Genetic differentiations (F(ST) values) between all pairs of populations, except between sub-alpine populations, were significantly different from zero (P < 0.001). Cluster analysis of morphological characters and a dendrogram constructed from genetic distances were broadly consistent with the classification into fat-tailed, thin-tailed and fat-rumped sheep. Bayesian cluster analysis using microsatellite markers indicated that there has been further genetic differentiation after the initial introduction of sheep into Ethiopia. Investigation of factors associated with genetic variation showed that an isolation-by-distance model, independently of other factors, explained most of the observed genetic variation. We also obtained a strong indication of adaptive divergence in morphological characters, patterns of morphological variation being highly associated with ecology even when the effect of neutral genetic divergence (F(ST)) was parcelled out in partial Mantel tests. Using a combination of F(ST) values, Bayesian clustering analysis and morphological divergence, we propose a classification of Ethiopian sheep into six breed groups and nine breeds.     

Serogenetic variation in four caste populations of Haryana, India

The phenotypes and gene frequencies of 3 blood groups, 7 red-cell enzymes and a serum protein were studied in 4 caste population groups of Haryana, North India. The results indicate that the distribution of these blood markers is rather homogeneous in the 4 groups and generally resembles that observed in various populations from neighbouring North Indian states.     

Song characteristics and morphological traits in four populations of the grasshopper Chorthippus biguttulus L.

We investigated four populations of the grasshopper Chorthippus biguttulus with respect to differences in morphological traits and characteristics of their communication signals. A special focus was laid on possible correlations between morphological and song traits of males that could be used by females to infer quality cues of potential mates. We also tested whether females exhibit preferences for males of their own population. Specific song features (onset accentuation, offset, syllable period) of males—but not of females—differed between populations. We observed size differences both in males and females from different populations, but the size ranks of the two sexes were not always correlated. Environmental factors appear to have a strong influence on different size traits, compared to genetic origin. In all populations a specific song feature, the accentuation of syllable onsets, showed a similar correlation with a morphological trait, hind leg size, but its correlation with other size indicators sometimes differed in sign. Females did not prefer songs of males from their own population. The best predictor for song attractiveness was—unexpectedly—not the onset accentuation but the offset depth.     

Anthropological evaluation of left-right differences in the femur of southern African populations

Bilateral asymmetries were tested on a series of anthropological measurements recorded from 566 femora of 161 males and 122 females of southern African populations. Uni- and multivariate statistics revealed that there is a high degree of side differences apparent in the morphological features of the femur, and close to 75% of all femora could be correctly assigned to their respective sides. While most dimensions were greater on the left side, anteroposterior diameter of the proximal shaft, bicondylar width and collo-diaphyseal angle yielded significantly higher mean values on the right side. Anteroposterior diameter of the proximal shaft loaded highest in both canonical discriminant analyses. This result indicates that, overall, the left leg is stronger and is more suited to withstand axial forces and mediolateral bending. Thus, the findings seem to further support the hypothesis that most people, regardless of handedness, use their left leg for weight-bearing, whereas the right leg is more likely to be used for other tasks.     

Additional evidence for bone technology in the southern African Middle Stone Age

Few Middle Stone Age sites have yielded convincing evidence for a complex bone technology, a behavior often associated with the emergence of modern cultures. Here, we review the published evidence for Middle Stone Age bone tools from southern Africa, analyze an additional nine bone artifacts recently recovered from Middle Stone Age levels at Blombos Cave, describe an unpublished bone tool from probable Middle Stone Age levels at Peers Cave, examine a single bone awl found at Blombosch Sands (an open site near Blombos Cave), and reappraise marked bone artifacts and a bone point recovered from Klasies River. To determine the chronological and cultural attribution of these artifacts, document bone-manufacturing techniques associated with the southern African MSA, and discuss the symbolic significance of the markings present on some of these objects we use (1) available contextual information; (2) morphometric comparison of Later Stone Age, Modern San, and purported Middle Stone Age projectile points; (3) analysis of the carbon/nitrogen content of bone tools and faunal remains from Peers and Blombos caves; and (4) microscopic analysis of traces of manufacture and use. Previously undescribed bone artifacts from Blombos Cave include a massive point manufactured on weathered bone, two complete awls and two awl tips manufactured on small-sized mammal and bird bone, a probable projectile point with a tang manufactured by knapping and scraping, a shaft fragment modified by percussion, used as retoucher and bearing a set of incised lines on the middle of the periosteal surface, and two fragments with possible engravings. The point from Peers Cave can be assigned to the Middle Stone Age and bears tiny markings reminiscent of those recorded on projectile points from Blombos and used as marks of ownership on San arrow points. The awl from Blombosch Sands and the bone point from Klasies River can be attributed to the Later Stone Age. Two notched objects from Klasies are attributed to the Middle Stone Age and interpreted as tools used on soft material; a third object bears possible deliberate symbolic engravings. Although low in number, the instances of bone artifacts attributable to the Middle Stone Age is increasing and demonstrates that the bone tools from Blombos Cave are not isolated instances. New discoveries of bone tools dating to this time period can be expected.     

Host-correlated morphological variation of Myzus persicae (Hemiptera: Aphididae) populations in Greece

Morphological variation in nine characters of 157 clones of Myzus persicae (Sulzer) was examined by multivariate analysis. The clones were collected from peach, Prunus persica, the primary host and the secondary hosts tobacco, Nicotiana tabacum, cabbage, Brassica oleracea, sugarbeet, Beta vulgaris and pepper Capsicum annuum. The 156 clones originated from various regions of Greece, both in the north, where a large part of the population has an annual bisexual generation on peach, and in more southerly regions, where populations are predominantly unisexual. One clone was collected from tobacco in Caserta, Italy. All clones were laboratory-reared on potato. Canonical variate analysis, hierarchical cluster analysis and a non-parametric classification tree method both revealed morphological differences associated with the host-plant on which they were collected. The scores of the first two canonical variates separated the tobacco-feeding clones from those originating from other secondary host-plants. However, in tobacco-growing areas the tobacco-feeding form predominated in spring populations on peach, and was sometimes found on other secondary hosts. In addition, using cluster analysis, the clones from tobacco which were sampled in the most southeasterly region showed a relatively large phenotypic distance from those collected further north and west. Moreover, clonal phenotypes were affected both by host plant and by long-term parthenogenetic rearing. However, in spite of these effects, the tobacco form was generally distinguishable from aphids originating from other hosts, indicating that the difference must have a genetic basis. In separate analyses of the clones originating from secondary hosts no association was found between morphology and either life cycle category or colour. Discriminant analysis showed that 89% of 1723 specimens could be correctly classified into the two groups.     

Non-metric variation of the skull in samples of four Indian populations

Four skeletal samples from the states of Uttar Pradesh, Bihar, and Andhra Pradesh in India are compared using cranial non-metric traits. The skeletal “epigenetic” distances correspond with the geographic pattern of separation, also demonstrating variable correspondence with known genetic relationships of the living populations.