Assessment of the population structure of five Finnish dog breeds with microsatellites

Genetic variabilities within and between Finnish populations of Golden Retrievers, German Shepherds, Wirehaired Dachshunds, Pembroke Welsh Corgis and Bedlington Terriers were quantified with microsatellite allele numbers, observed heterozygosities, expected heterozygosities, FIS estimates, FST estimates and DS distances. In a sample of 50 individuals from each, breed and ten polymorphic loci, the highest genetic diversity was exhibited in the Wirehaired Dachshunds and lowest in the Bedlington Terriers. Although statistically significant deviations from the Hardy-Weinberg (H-W) equilibrium were observed, they occurred at an unexpectedly low frequency. Most strikingly, the extremely small Bedlington Terrier population displayed genotypes in H-W proportions in all investigated loci. The H-W deviations always occurred with positive FIS estimates, which, on average, were not larger than values reported for free-living canids. Genetic differentiation between the breeds was very large. As a comparison, present estimates were, on average, over two times higher than previously observed between breeds of sheep, and over two times higher than the highest estimates reported between human populations. Moreover, the highest DS distances were only slightly lower than the lowest values inferred between humans and chimpanzees. Severe bottlenecks in the recent past of the examined breeds were not statistically supported. The presented data imply genetic isolation and intense artificial selection in the history of these breeds of dogs.     

周口店变异狼(Canis lupus variabilis)在家畜狗(Canis familiaris)祖先系列中的位置

本文作者对周口店第一、第三及第十三地点的一种化石犬类——变异狼(Canis lupus uariadilis)进行了观察和测量。根据其头骨大小、形态特征以及与中国早期人类共生的情况来看,认为它有可能是从驯化的野生狼导致家畜狗出现的一种祖先类型。     

DOGSET: pre-designed primer sets for fine-scale mapping and DNA sequence interrogation in the dog

DOGSET is an online resource that provides access to primer sequences that have been computationally mined from the reference genome using heuristic algorithms. The electronic repository includes PCR primers corresponding to 32 135 markers for genetic mapping and 334 657 sequence-tagged gene elements for targeted re-sequencing and mutation discovery. A customized report that tailors primer design to wet bench protocols can be exported for a region of interest by specifying genome coordinates in a graphical user interface.     

Domestic dogs as an edge effect in the Brasília National Park, Brazil: interactions with native mammals

Edge effects are a well-known result of habitat fragmentation. However, little has been published on fragmentation, isolation and the intrusive influence from the surrounding matrix at the landscape level. The objectives of the present study are to evaluate the presence of dogs in the Brasília National Park (BNP) in relation to habitat type and the influence from the surrounding matrix. In addition, this study examines the response of the native mammal fauna to the presence of dogs. Track stations were built along dirt roads in the BNP and subsequently examined for the presence or absence of tracks. We used a stepwise logistic regression to model the occurrence of five mammal species relative to habitat variables, with an α =0.05 to determine whether to enter and retain a variable in the model. A simulation of each species occurrence probability was conducted using a combination of selected habitat variables in a resource selection probability function. Results indicate a negative relationship between distance from the BNP edge and the probability of dog occurrences. From an ecological perspective, the presence of dogs inside the BNP indicates an edge effect. The occurrence of the maned wolf was positively associated with distance from a garbage dump site and negatively associated with the presence of dog tracks. The maned wolf and giant anteater seem to avoid areas near the garbage dump as well as areas with dog tracks. There is no support for the possible existence of a feral dog population inside the BNP, but the effects of free-ranging dogs on the wildlife population in such an isolated protected area must not be neglected. Domestic dog Canis familiaris populations and disease control programs should be established in the urban, sub-urban and rural areas surrounding the BNP, along with the complete removal of the garbage dump from the BNP surroundings.     

Behavioral and Self-report Measures Influencing Children's Reported Attachment to Their Dog

Despite the prevalence of dogs as family pets and increased scientific interest in canine behavior, few studies have investigated charac- teristics of the child or dog that influence the child–dog relationship. In the present study, we explored how behavioral and some self-report measures influence a child's reported attachment to their dog, as assessed by the Lexington Attachment to Pets Scale (LAPS). We tested specifically whether children (n = 99; mean age = 10.25 years, SD = 1.31) reported stronger attachment to dogs that were perceived as being more supportive (mea- sured by a modified version of the Network of Relationships Inventory), that were more successful in following the child's pointing gesture in a standard two-object choice test, or that solicited more petting in a sociability assess- ment. In addition, we assessed whether children's attachment security to their parent and being responsible for the care of their dog influenced re- ported attachment to the dog. Overall, perceived support provided by the dog was highly predictive of all subscales of the LAPS. The dog's success in following the child's pointing gestures and lower rates of petting during the sociability assessment were associated with higher ratings on the General Attachment subscale of the LAPS, but not on the other subscales. Caring for the dog did not predict the child's reported attachment to the dog, but did predict the dog's behavior on the point-following task and petting during the sociability task. If the child cared for the dog, the dog was more likely to be successful on the pointing task and more likely to be petted. These results indicate a dyadic relationship in which the child's care for the dog is associ- ated with the dog's behavior on the behavioral tasks, which in turn is related to the child's reported attachment to their dog. The direction of influence and nature of this dyad will be a fruitful area for future research.     

Correlated Non-native Species Richness of Birds, Mammals, Herptiles and Plants: Scale Effects of Area, Human Population and Native Plants

Several extrinsic factors (area, native species diversity, human population size and latitude) significantly influence the non-native species richness of plants, over several orders of magnitude. Using several data sets, I examine the role of these factors in non-native species richness of several animal groups: birds, mammals and herptiles (amphibians, reptiles). I also examine if non-native species richness is correlated among these groups. I find, in agreement with Sax [2001, Journal of Biogeography 28: 139–150], that latitude is inversely correlated with non-native species richness of many groups. Once latitude is accounted for, area, human population size and native plant species richness are shown to be important extrinsic factors influencing non-native animal species. Of these extrinsic factors, human population size and native plant species richness are the best predictors of non-native animal species richness. Area, human population size and native plant species richness are highly intercorrelated, along with non-native species richness of all taxa. Indeed a factor analysis shows that a single multivariate axis explains over half of the variation for all variables among the groups. One reason for this covariation is that humans tend to most densely occupy the most productive and diverse habitats where native plant species richness is very high. It is thus difficult to disentangle the effects of human population size and native species richness on non-native species richness. However, it seems likely that these two factors may combine to increase non-native species richness in a synergistic way: high native species richness reflects greater habitat variety available for non-native species, and dense human populations (that preferentially occupy areas rich in native species) increase non-native species importation and disturbance of local habitats.     

北京东灵山地区辽东栎、大叶白蜡和五角枫种群分布格局与动态

对北京东灵山地区 3块样地中的辽东栎 (QuercusliaotungensisKoidz .)、大叶白蜡 (FraxinusrhynchophyllaHance)和五角枫 (AcermonoMaxim .)种群的分布格局和种群动态进行了考察。调查 3块样地中每个树种的全部个体 ,按高度将它们分为 4个不同龄级 ,用相邻格子样方法进行取样。在研究分布格局时 ,计算了扩散系数C、扩散型指数Iδ 与IA、CA 指数和聚块指数m /m等各项指标 ,测定它们的分布格局 ,并通过计算拟合它们的分布类型。结果表明 ,不同地点各种群的幼苗 (<0 .4m)、小幼树 (0 .4～ 1m)和大幼树 (1～ 2m)绝大多数呈聚集分布 ,少量呈随机分布 ;成林辽东栎成熟个体 (≥ 2m)是一种介于均匀分布和随机分布之间的状态 ,幼林辽东栎成林和灌丛大叶白蜡属于随机分布 ,成林大叶白蜡和五角枫、灌丛辽东栎呈聚集分布。在研究种群动态时 ,分别作出每个种群的龄级结构图 ,再对同一样地不同种群以及同一种群不同龄级个体的数量差异进行最小显著差法 (LSD)检验和比较 ,结果表明检验结果和龄级结构图显示出来的趋势是一致的 ,即成林辽东栎种群具有较稳定的结构 ,成林大叶白蜡和五角枫表现为增长型结构 ,幼林辽东栎、大叶白蜡和五角枫都表现为衰退型结构 ,灌丛辽东栎具有稳定型结构 ,灌丛大叶白蜡具有增长型结构。研究     

蔬菜花期蓟马的种群动态与空间分布研究

西花蓟马是近年来在我国局部地区暴发成灾的重要外来入侵害虫,有关西花蓟马入侵对本地蓟马种群动态、空间分布及优势种影响的报道较少。对云南省昆明市近郊蔬菜花期的蓟马种群动态和空间分布研究表明,蔬菜上的蓟马种类主要是西花蓟马Frankliniella occidentalis(Pergande)、花蓟马F.intonsa(Trybom)、棕榈蓟马T.palmi(Karny)和端大蓟马Megalurothrips distalis(Karny);不同蔬菜上的蓟马优势种存在一定差异,其中辣椒和茼蒿上的蓟马优势种为西花蓟马;韭菜、茄子和四季豆上的蓟马优势种分别为花蓟马、棕榈蓟马和端大蓟马。各蔬菜上的蓟马种群数量以花期为多,盛花期达最大值,其中茄子花上的蓟马成虫平均虫口密度最高,为14.93头/朵。利用聚集度指标进行空间分布检测表明,不同蔬菜上蓟马成虫的空间分布型均为聚集分布,且聚集程度随密度的增加而增大。本研究可为深入探讨西花蓟马对本地蓟马的竞争取代机制积累资料,同时为西花蓟马的综合治理奠定理论基础。     

Decline of Native Freshwater Fishes in a Mediterranean Watershed on the Iberian Peninsula: A Quantitative Assessment

We examined changes in the distribution of 9 native and 18 introduced freshwater fishes in the south-eastern Pyrenees watershed, Iberian Peninsula, using data from 1996, 1984–1988 and historical information. This region suffers many modifications to its freshwater ecosystems that are linked to human activity in the Mediterranean regions. Fish communities, stream physical habitat and environmental degradation were assessed at 168 sites from 11 basins in 1996. Seven native species (78%) showed decline from previous data, one of which became extirpated in the first half of the 20th century. On the other hand, introduced species are expanding. As a consequence, intact native communities are increasingly rare, declining from presence in 22% of river courses in 1984–1988 to 15% in 1996. The most typical community type is a mixture of native and introduced species occupying 30% of river courses. Stream degradation seems to be the main cause of this process because fish communities differed between degraded streams and streams suffering less impact. A principal component analysis showed that water pollution and modifications to the habitat were the two anthropogenic factors that accounted for most changes in the fish community integrity. Habitat alteration, primarily through construction of dams and water diversions, has fragmented habitats and isolated native fish communities in headwater streams. Current protection measures do not offer effective conservation of threatened species and communities. A global conservation and restoration programme from an ecosystem-based approach is essential to reverse the trend affecting native freshwater fishes in this Mediterranean region.     

From the Apennines to the Alps: colonization genetics of the naturally expanding Italian wolf (Canis lupus) population

Wolves in Italy strongly declined in the past and were confined south of the Alps since the turn of the last century, reduced in the 1970s to approximately 100 individuals surviving in two fragmented subpopulations in the central-southern Apennines. The Italian wolves are presently expanding in the Apennines, and started to recolonize the western Alps in Italy, France and Switzerland about 16 years ago. In this study, we used a population genetic approach to elucidate some aspects of the wolf recolonization process. DNA extracted from 3068 tissue and scat samples collected in the Apennines (the source populations) and in the Alps (the colony), were genotyped at 12 microsatellite loci aiming to assess (i) the strength of the bottleneck and founder effects during the onset of colonization; (ii) the rates of gene flow between source and colony; and (iii) the minimum number of colonizers that are needed to explain the genetic variability observed in the colony. We identified a total of 435 distinct wolf genotypes, which showed that wolves in the Alps: (i) have significantly lower genetic diversity (heterozygosity, allelic richness, number of private alleles) than wolves in the Apennines; (ii) are genetically distinct using pairwise F(ST) values, population assignment test and Bayesian clustering; (iii) are not in genetic equilibrium (significant bottleneck test). Spatial autocorrelations are significant among samples separated up to c. 230 km, roughly correspondent to the apparent gap in permanent wolf presence between the Alps and north Apennines. The estimated number of first-generation migrants indicates that migration has been unidirectional and male-biased, from the Apennines to the Alps, and that wolves in southern Italy did not contribute to the Alpine population. These results suggest that: (i) the Alps were colonized by a few long-range migrating wolves originating in the north Apennine subpopulation; (ii) during the colonization process there has been a moderate bottleneck; and (iii) gene flow between sources and colonies was moderate (corresponding to 1.25-2.50 wolves per generation), despite high potential for dispersal. Bottleneck simulations showed that a total of c. 8-16 effective founders are needed to explain the genetic diversity observed in the Alps. Levels of genetic diversity in the expanding Alpine wolf population, and the permanence of genetic structuring, will depend on the future rates of gene flow among distinct wolf subpopulation fragments.     

珍稀濒危树种陆均松天然种群结构与空间分布格局

为研究陆均松(Dacrydium pectinatum)种群生存现状及分布格局,对BWL、DLS、JFL三种不同分布区域的陆均松天然种群进行了调查,分析了其天然群落乔木层物种多样性及优势种组成、龄级结构及分布格局三个方面的空间异质性,结果表明:(1)三种陆均松天然群落乔木层物种丰富度及多样性指数均较高,基本表现为BWL>JFL>DLS,且远高于中高纬度温带及亚热带森林群落;群落内多为小密度种群,少有占绝对优势地位的树种,符合热带山地雨林物种组成的一般规律。(2)龄级结构有所差异,BWL和JFL种群呈衰退趋势,共同特点是幼年树数量较少,成年和老年树比例较高;DLS种群幼年树数量在所有个体中比例最高,属于增长型种群。(3)BWL和DLS种群整体呈聚集分布,幼年至老年阶段由聚集分布转变为均匀分布,JFL种群整体及不同发育阶段均呈均匀分布状态;聚集强度表现为DLS>BWL>JFL,幼年树>成年树>老年树。陆均松是热带山地雨林的关键种和建群种,对研究海南热带雨林的起源及其区系特征具有重要意义,针对其生存现状,可根据实际情况,利用人工辅助措施如开辟林窗、合理疏伐...