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1.
The Gray Wolf is a wide ranging carnivore in Iran, absent only in the central deserts and Dasht-e Lut. This study was carried out to verify whether, despite their high mobility, individual wolves belonging to different populations show morphological variations in the skull. We collected 48 skulls from various regions of Iran and measured 24 variables on the cranium. These primary variables were then used to generate six indices to examine any variations in the shape of the skulls collected in different regions of the country. Although the largest skulls collected for this study originated in the mountainous regions of the northwest, northeast, and west, principle component analysis (PCA) did not result in a meaningful difference in the size and shape of wolf skulls in different regions of Iran. Our results confirm that the minor morphological variations of the skull in wolves of Iran are not an evidence for the separation of wolf populations in different regions or the existence of various subspecies in the country. This uniformity can be explained by the strong gene flow among populations as well as high mobility of the wolf that facilitates movement of individuals between populations. 相似文献
2.
S. R. Hedges 《Journal of Zoology》1969,159(4):425-442
The main object of this study was to use discontinuous variation as a means of measuring divergence between populations of A. sylvaticus (L.) and A. flavicollis (Melchior) from Britain and Eurasia. Samples from 17 populations (671 skulls) were each classified for 20 discontinuous morphological variants. The investigation has shown that certain epigenetic variants have a characteristic incidence in populations of the two species and that the relative incidence of the variants could be used as an aid to specific separation. The calculation of degree of divergence between the populations has made it possible to suggest the order in which populations are related to each other. 相似文献
3.
We examined the skulls of 72 bottlenose dolphins from the Indian and western Pacific Oceans to clarify the systematics in
genusTursiops. We also examined type skulls ofTursiops aduncus (Ehrenberg, 1832),T. eurynome (Gray, 1846),T. catalania (Gray, 1862),Delphinus (Steno) gadamu Owen 1866,T. dawsoni Lydekker 1908, andT. truncatus (Montagu, 1821). The specimens were divided into two groups, A and B, based on rostrum length and characters of the basal
part of the rostrum. The rostrum of group A was longer and tapered abruptly near the base, whereas that of group B was shorter
and tapered more gradually throughout its length. Group A contained specimens from western, central, and eastern Asia, Africa,
and Australasia. Group B contained specimens from central and eastern Asia and Australasia. The six type skulls were also
clearly divided into two groups; the type skulls ofT. aduncus, T. catalania, andDelphinus (Steno) gadamu were included in group A, whereas the type skulls ofT. truncatus, T. eurynome, andT. dawsoni were included in group B. This grouping was consistent with the genetic status. Therefore, we identified group A specimens
asT. aduncus and group B specimensT. truncatus, the oldest scientific names related to the two groups. 相似文献
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5.
McGowen MR 《Molecular phylogenetics and evolution》2011,60(3):345-357
Oceanic dolphins (Delphinidae) are the product of a rapid radiation that yielded ~36 extant species of small to medium-sized cetaceans that first emerged in the Late Miocene. Although they are a charismatic group of organisms that have become poster children for marine conservation, many phylogenetic relationships within Delphinidae remain elusive due to the slow molecular evolution of the group and the difficulty of resolving short branches from successive cladogenic events. Here I combine existing and newly generated sequences from four mitochondrial (mt) genes and 20 nuclear (nu) genes to reconstruct a well-supported phylogenetic hypothesis for Delphinidae. This study compares maximum-likelihood and Bayesian inference methods of several data sets including mtDNA, combined nuDNA, gene trees of individual nuDNA loci, and concatenated mtDNA+nuDNA. In addition, I contrast these standard phylogenetic analyses with the species tree reconstruction method of Bayesian concordance analysis (BCA). Despite finding discordance between mtDNA and individual nuDNA loci, the concatenated matrix recovers a completely resolved and robustly supported phylogeny that is also broadly congruent with BCA trees. This study strongly supports groupings such as Delphininae, Lissodelphininae, Globicephalinae, Sotalia+Delphininae, Steno+Orcaella+Globicephalinae, and Leucopleurus acutus, Lagenorhynchus albirostris, and Orcinus orca as basal delphinid taxa. 相似文献
6.
Cedeño-Vázquez JR Rodriguez D Calmé S Ross JP Densmore LD Thorbjarnarson JB 《Journal of experimental zoology. Part A, Ecological genetics and physiology》2008,309(10):661-673
The American crocodile (Crocodylus acutus) and the Morelet's crocodile (C. moreletii) are broadly sympatric in Belize and Mexico. The presence of morphologically anomalous individuals in the overlapping range area suggests possible hybridization between these species. Analysis of 477 base pairs of the mitochondrial tRNA(Pro)-tRNA(Phe)-Dloop region revealed the presence of pure C. acutus (N=43) and C. moreletii (N=56), as well as a high proportion of interspecific hybrids (N=17, 14.6%) in the Yucatan Peninsula, Mexico. Although all individuals could be assigned to one species or other based on phenotypic characters, some had been characterized as potential hybrids in the field by anomalous scale counts. The hybridization zone lies along the area of sympatry between C. acutus and C. moreletii investigated in this study, but extends further inland if hybrid localities from Belize are included. Hybridization in the Yucatan Peninsula is bidirectional, which indicates considerably more genetic contact between these species than previously recognized, and is probably more detrimental to the genetic integrity of smaller C. acutus populations. A more intensive study of the pattern of hybridization is warranted and supports continued classification of C. acutus as a critically threatened species in the Yucatan Peninsula. 相似文献
7.
A Gawlikowska J Szczurowski F Czerwiński D Miklaszewska E Adamiec E Dziecio?owska 《HOMO》2007,58(2):159-172
The analysis of fluctuating asymmetry (FA) allows for estimating the influence of stress factors on human development and allows to evaluate resistance to stress. FA is often used as a marker of prenatal stress. The aim of this work is to estimate the symmetry of skulls from selected historic human populations and to analyse changes in their morphology which have taken place over centuries. The studied material consisted of two skull samples - a modern sample containing 82 skulls and a medieval sample of 77 skulls from Gródek on the Bug River. Radiographs were taken in postero-anterior (P-A) and base projections. Images were scanned and calibrated by means of MicroStation 95 Academic Edition software. Measurements of the skull images were used to estimate FA. All data were analysed statistically. The skulls in both samples showed asymmetry. The levels of FA varied in different skull regions. A high level of FA in the calvaria and a low asymmetry for the facial part of skull is characteristic of modern skulls. In medieval skulls these relations are inverted. The higher value of FA in modern skulls is an evidence of a higher level of developmental stress in the modern population as well as of its lesser abilities to resist stress. 相似文献
8.
CINO PERTOLDI VOLKER LOESCHCKE ANJA BRAUN AKSEL BO MADSEN ETTORE RANDI 《Biological journal of the Linnean Society. Linnean Society of London》2000,70(2):309-323
Morphometrical univariate analyses of otter skulls collected over the past hundred years in European countries from presumed healthy populations were compared with skulls from presumed endangered populations. The average degree of sexual dimorphism of die European populations was found to be directly correlated to die skull size of die male otters. Fluctuating asymmetry (FA) in metric skull traits was analysed as an estimator of developmental stability. There was evidence for increased FA in different traits over time in some of the presumed endangered populations, and for a reduction in size of skull traits. In contrast, the healthy populations did not show any significant changes in the same traits during the same period. The reduced sexual dimorphism of the endangered populations is suggested to be a product of relaxed sexual selection and deteriorated habitat conditions. Environmental and genetic forces that may have shaped these patterns are discussed. 相似文献
9.
Asymmetry in East African skulls 总被引:1,自引:0,他引:1
Skulls from 297 East Africans were examined in relation to their symmetry; 98% were found to be asymmetrical. The most common types of asymmetry were right fronto-petalia, left parieto-petalia, and left occipito-petalia (21.2%). No significant differences were found among the East African populations. Sixteen per cent of the skulls had wormian bones, all of which were found in asymmetrical skulls. The problem of asymmetry of skulls is discussed and the literature on the subject reviewed. 相似文献
10.
Rodriguez D Cedeño-Vázquez JR Forstner MR Densmore LD 《Journal of experimental zoology. Part A, Ecological genetics and physiology》2008,309(10):674-686
Detecting and quantifying hybridization between endangered or threatened taxa can provide valuable information with regards to conservation and management strategies. Hybridization between members of the genus Crocodylus has been known to occur in captivity and in some wild populations. We tested for hybridization among wild populations of American crocodile (C. acutus) and Morelet's crocodile (C. moreletii) in the Yucatan Peninsula by comparing Bayesian assignment tests, based on microsatellite data, to mitochondrial and morphological assignments. Skin clips from 83 individuals were taken for genetic identification, and a total of 32 individuals (38.6%) exhibited some evidence of hybridization by combined morphological, mitochondrial and microsatellite analyses. The majority of hybrids were classified as F(2) hybrids and backcrosses to C. moreletii. Most of the introgression occurs in two national biosphere reserves located on the northern and eastern coasts of the Yucatan Peninsula. Preliminary tests did not find a significant decrease in hybridity across three life stages, thus far indicating a low level of selection against hybrids. Model-based analyses on multilocus genotypes of pure individuals returned little geographic partitioning in both C. acutus and C. moreletii. 相似文献
11.
山东济宁潘庙汉代墓葬人骨研究 总被引:3,自引:0,他引:3
本文对潘庙遗址汉代墓葬出土的11例成年颅骨(男性7例,女性4例)进行了研究。颅骨的测量性状和非测量性状的分析表明,潘庙汉代居民在若干主要体质特征上具有亚洲蒙古人种的特点,并且与东亚蒙古人种最相近似。在潘庙汉代居民中存在着颅骨枕部人工变形的习俗,这一特点与大汶口文化的新石器时代居民颇为相似。 相似文献
12.
对磐安县1973年 ̄1985年的蛇伤流行病学进行了回顾性调查。普查了全国2个国营林场、1个农场、356个行政村屯。13年累计人口2412884人,其中蛇伤数为735人次(男546人次,女189人次),死亡10人。年平均发病数56.54人,发病率为29.7/万,年均病死0.77人,病死率为1.77%,死亡率为0.037/万。各种致伤蛇种数高低依次是蛇蛇、竹叶青蛇、五步蛇、眼镜蛇、银环蛇、烙铁头蛇等。 相似文献
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14.
半圈养条件下白唇鹿行为时间分配及活动规律的研究 总被引:10,自引:3,他引:10
白唇鹿 (Cervus albirostris)是我国青藏高原特有种 ,在鹿类进化史上极其重要。因其药用价值很高 ,几十年来捕杀现象严重 ,数量大为减少 ,濒于灭绝 ,1 988年被列为国家一级保护动物 [13 ] 。目前白唇鹿分布在 2 9°~ 40°N,92°~ 1 0 2°E的区域内[1] 。它们主要活动于海拔 350 0~ 50 0 0 m之间的高寒半荒漠草原 ,高山草甸草原和亚高山灌丛草原 [7] 。国内对白唇鹿的研究 ,涉及到食性[7,11] 、繁殖[3~ 5] 、形态、生态地理分布[6] 等 ,而对白唇鹿非发情期行为时间分配尚无报道。 1 998年 3~ 4月我们在上海野生动物园对其进行了专题研… 相似文献
15.
研究对分布于横断山区(从北到南:巴塘、中甸、宁蒗、景东)的高山姬鼠头骨背面、腹面、侧面及下颌侧面的形态特征进行主成分分析、判别分析、薄片样条分析和多维尺度分析,以进一步探讨高山姬鼠头骨形态变异与环境之间的关系。研究结果表明,高山姬鼠头骨的背面和腹面在研究多种群头骨形态时更适宜,更有参考价值;经过薄片样条法分析显示形变集中在鼻骨、眼眶和臼齿,这可能与高山姬鼠生存的横断山从北到南的气候和地理环境变化相关;经多维尺度分析显示横断山地区的高山姬鼠的头骨发生了变异,这可能与高山姬鼠生活环境的经度和纬度有关。综上,横断山区的高山姬鼠种群的头骨形态有一定的变异,这可能反映了其对横断山不同生态环境的形态适应性变异. 相似文献
16.
A multivariate examination of cranial variation within and between European populations of Meles meles (L.) revealed that populations from Ireland, Great Britain, Norway, and the Slovak Republic could be differentiated both by cranial form and by the degree of sexual dimorphism exhibited. Irish material was characterized by low sexual dimorphism, particularly when compared to Slovak specimens. Badgers from the British Isles had larger skulls than other samples and were more similar to each other than they were to badgers from mainland Europe. Size played a greater role in differentiating samples of female badgers than it did in males. Significant variation occurred within the British Isles, with individual samples being highly differentiable. There was, however, little relationship between morphological similarity and geographic proximity. We contend that macrogeographical (between-country) variation in the species is primarily determined by historical factors and adaptation to current conditions, while microgeographic (within-country) variation is a result of selectively neutral processes. 相似文献
17.
Morphological variation of the introduced perennial Solidago canadensis L. sensu lato (Asteraceae) in Europe 总被引:1,自引:0,他引:1
EWALD WEBER 《Botanical journal of the Linnean Society. Linnean Society of London》1997,123(3):197-210
Morphological and life-history variation within and between 23 European populations of the introduced and widespread perennial Solidago canadensis L. sensu lato (Asteraceae) was investigated. The populations differed significantly in all 19 characters measured. Coefficients of variation and intraclass-correlations were high for characters related to growth. Floral characters (involucral height, number of disk florets, number of ray florets), and pubescence of stems and leaves varied considerably among sampled shoots, but their frequency distributions were unimodal and the coefficients of variation low. The first three principal components explained 48% of the variation and formed no dusters among the shoots. Several character means correlated with latitude, indicating clinal variation among the populations. Comparison of variation in floral and leaf characters with data from the native range suggests that S. canadensis s.l. naturalized in Europe belongs to a taxon that is close to S. canadensis var. scabra (Muhl.) Torr. & Gray ( S. altissima L.), despite the reported diploid chromosome number of this taxon in Europe. 相似文献
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l-Threonic acid is a natural constituent in leaves of Pelargonium crispum (L.) L'Hér (lemon geranium) and Rumex x acutus L. (sorrel). In both species, l-[(14)C]threonate is formed after feeding l-[U-(14)C]ascorbic acid to detached leaves. R. acutus leaves labeled with l-[4-(3)H]- or l-[6-(3)H]ascorbic acid produce l-[(3)H]threonate, in the first case internally labeled and in the second case confined to the hydroxymethyl group. These results are consistent with the formation of l-threonate from carbons three through six of l-ascorbic acid. Detached leaves of P. crispum oxidize l-[U-(14)C] threonate to l-[(14)C]tartrate whereas leaves of R. acutus produce negligible tartrate and the bulk of the (14)C appears in (14)CO(2), [(14)C]sucrose, and other products of carbohydrate metabolism. R. acutus leaves that are labeled with l-[U-(14)C]threonate release (14)CO(2) at linear rate until a limiting value of 25% of the total [U-(14)C]threonate is metabolized. A small quantity of [(14)C]glycerate is also produced which suggests a process involving decarboxylation of l-[U-(14)C]threonate. 相似文献
20.
We made a preliminary survey of the present status and ecology of the White-lipped Deer (Cervus albirostris) in the upper Huang He and Chang Jiang River regions of China. Eight mixed herds, ranging in size from 5 to 46 animals each, were observed. The deer lived from the rhododendron scrub just above the spruce forests to alpine grasslands, ranging in altitudes from 4000 to 5000 m. The peak of the rut occurred in October, when breeding herds were composed of a few large stags and hinds. The pasturing of domestic animals in the area influences not only the spatial distribution of the deer, but also the timing of seasonal shifts. The main distribution of the deer is in western Sichuan Province and some scattered populations in Qinghai Province are endangered. The species could survive, given adequate protection. 相似文献