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11.
Svetlana A. Semerikova Vladimir L. Semerikov Martin Lascoux 《Journal of Biogeography》2011,38(2):326-340
Aim The main aim of the present study is to infer the post‐glacial history of Abies species from north‐east Asia and to test the hypotheses that coastal Abies populations suffered less from climatic fluctuations during Pleistocene glacial periods than their more continental counterparts, and that Sakhalin was a major area of introgression. Location Natural ranges of the fir species Abies nephrolepis, Abies sachalinensis and Abies holophylla in the Russian Far East, and of Abies gracilis, which is endemic to the Kamchatka Peninsula. Methods Nineteen populations were sampled for allozyme analysis. Seventeen of these populations were also screened for variation at two paternally inherited chloroplast DNA microsatellite loci (cpSSR) and variation at one maternally inherited mitochondrial marker (nad4‐3/4). Finally a subset of 11 populations was analysed with amplified fragment length polymorphism (AFLP). Comparisons were made with already available Abies sibirica data. For all sets of markers, we estimated genetic diversity and differentiation using an analysis of molecular variance (AMOVA). Population clustering was assessed with a Bayesian approach implemented in structure v.2.3. Results Among the three major species, A. sibirica, A. nephrolepis and A. sachalinensis, A. sachalinensis demonstrated the highest cytoplasmic and nuclear diversity and the most continental species, A. sibirica, the lowest. Both nuclear and mitochondrial DNA markers revealed the presence of a transitional zone on Sakhalin Island between A. nephrolepis and A. sachalinensis of south Sakhalin. The structure analysis delivered very clear results confirming the admixed origin of A. sachalinensis, with a genetic contribution from A. nephrolepis. No variation in cytoplasmic markers was found in A. gracilis, suggesting the occurrence of a recent bottleneck. Main conclusions There is a clear reduction of genetic diversity in Abies species from the Pacific coast into the continent. The higher diversity in A. sachalinensis could have two causes: a larger effective population size in the islands due to relatively stable climatic conditions and consequently less pronounced demographic fluctuations in population size and/or hybridization with continental and Japanese populations. Sakhalin Island is a major transitional zone for conifer species. Finally, the fir from Kamchatka, A. gracilis, should be regarded as a separate species closely related to the A. nephrolepis–A. sachalinensis complex. 相似文献
12.
《Acta Genetica Sinica》2010,(3)
The domestication of cattle fuelled the development of agricultural society in the history of human being.The evolution and genetic relationship of cattle can be elucidated by investigating the variation of mitochondrial DNA(mtDNA) D-loop sequence.In this study,we built a cattle phylogeny with a pool of 856 individual D-loop sequences,of which 264 Chinese cattle D-loop sequences were obtained in this study(141 ones were first analyzed,and 123 were first submitted) and the rest sequences of cattle from six A... 相似文献
13.
Aeschynanthus Jack, an epiphytic genus with c.160 species, is widespread in SE Asia. We selected 50 species for ITS nrDNA sequencing, to
include all biogeographic areas and all infrageneric groupings, which are currently based on seed morphology. Some species
were sequenced directly from PCR product; others cloned because of ITS length polymorphisms. The clone sequences were analysed
individually and combined in an elision matrix. Results extend earlier findings that Aeschynanthus is divided into two clades, one occurring primarily in mainland SE Asia and the other in Malesia. This pattern is interpreted
as indicating an ancient vicariance event followed by dispersal and plate fusion. Clade I has straight or clockwise spiral
orientation of the testa cells and clade II anticlockwise spiral orientation. In clade I some species of section Microtrichium form a basal group with other sections being polyphyletic or paraphyletic. In clade II the monophyletic section Aeschynanthus is nested within the paraphyletic basal Microtrichium.
Received February 8, 2001 Accepted June 8, 2001 相似文献
14.
Jean-Marc Thiollay 《Journal of Biogeography》1998,25(1):52-72
Ten diurnal raptor communities (Falconiformes) were studied in continental and peninsular situations, and on landbridge and oceanic islands of various sizes, from Southern India to Southern Vietnam and from Sri Lanka to Java. An index of abundance was derived from 1-km2 sample plots. A consistent decrease of species richness occurred from continent to peninsulas and to large landbridge islands, then more abruptly to oceanic islands. The impoverishment process was much faster for open habitat raptors than for forest species, and for rarest and most specialized raptors than for common and more generalist species. Large taxa survived on islands as well as smaller species. Specific habitat requirements, historical factors and forest fragmentation were probably more important determinants of community composition than land area itself. An insular syndrome was documented in forest species on islands, including significant examples of habitat niche expansion, interspecific segregation and density compensation. Some cases suggested that interspecific competition was involved. Such relaxation of habitat and density constraints may enhance the survival probability of these species on islands. 相似文献
15.
Tree growth sensitivity to climate can vary over space and time. This variability generates inconsistency in growth response to climate, which makes it difficult to assess the effects of past climate and global climate change on tree growth. A previous short-term study of Pseudopiptadenia contorta found a consistent growth response to climate in distinct locations, which raises the question, is the growth response of P. contorta to climate consistent over the long-term? We aimed to assess whether there is a common pattern of variation in tree-ring width, build tree-ring width chronologies, and verify the consistency of the climate-growth response of P. contorta in two Atlantic Forest remnants. Wood samples were collected in Reserva Biológica de Poço das Antas (RBPA) and Reserva Biológica de Tinguá (RBT) in the state of Rio de Janeiro, Brazil. Conventional dendrochronology methods were used for cross-dating, to build chronologies and to assess the climate-growth relationship. A common growth pattern was detected for P. contorta, and two tree-ring width chronologies were constructed. A congruent growth response was found for trees of RBPA and RBT to annual and spring precipitation as well as precipitation in the rainy months. Other climate-growth relationships were detected with other precipitation and temperature variables. Considering that P. contorta is a widespread species, occurring in other Brazilian biomes and forest formations, it is a promising model for developing further dendrochronological research including regional networks of replicated site chronologies, which could facilitate the reconstruction of historical climatic series and predictions of future impacts of climate change in tropical areas. 相似文献
16.
Michael Banton 《Ethnic and racial studies》2013,36(5):990-994
The question whether there are ethnic groups in South Asia is relevant to the application of international law, as when states report under the International Convention on the Elimination of All Forms of Racial Discrimination. Whether it is important to the advancement of social science is less certain. To classify certain groups as ethnic groups adds little to the explanation of the character of inter-group relations in the region. 相似文献
17.
N. Maaranen C. Stantis A. Kharobi S. Zakrzewski H. Schutkowski C. Doumet-Serhal 《American journal of physical anthropology》2023,182(3):428-439
Objectives
The Levantine Middle Bronze Age (MBA, circa 2000–1500 BCE) marks a period of increased trade and regional interaction, spurred on by technological developments. In light of previous research exhibiting limited mobility in Sidon, further investigation was conducted using biodistance analysis to understand local population history and site development.Materials and Methods
Dental nonmetric traits, a proxy for genetic information, were explored using ASUDAS on a sub-sample of primary inhumations (n = 35). The biodistance matrix was generated using Gower distance measures, and further tested using PERMDISP, PERMANOVA, Mantel test and hierarchical cluster analysis. The data was also contrasted to 87Sr/86Sr and δ18O as well as δ13C and δ15N values.Results
There were no significant diachronic differences in isotopes values, and there was biological continuity (n = 35, Mantel test r = 0.11, p = 0.02, comparing local phases and biodistance). The analysis also suggested of a sub-group of individuals with biological proximity shared a more limited range of mobility and dietary habits.Conclusions
The isotopes (87Sr/86Sr, δ18O, δ13C, δ15N) and biodistance analysis conducted on the Sidon College site skeletal assemblage exhibits stability and continuity of the people, despite the site's increasing role in the maritime network. This continuity may have been a key factor in Sidon's success, allowing it to accumulate wealth and resources for centuries to come.18.
Assessment of the conservation status of partridges and pheasants in South East Asia 总被引:3,自引:2,他引:1
The recent compilation of IUCN Action Plans for partridges and pheasants has highlighted the need for locality data to be used in conservation evaluation. Here we used locality data to measure changes in the proportion of localities from which each of 25 South East Asian species has been recorded, changes in their geographic extent and the amount of habitat that is potentially available to them. These are measures that use the data which are most readily available. Single landmass endemics from both montane and lowland forests appear to have fared badly with peacock pheasants Polyplectron and hill-partridges Arborophila suffering particularly large declines, although for montane forest species, these apparent declines are probably the result of relatively less survey effort in highland areas. Species previously widespread that give cause for concern include the green peafowl, Pavo muticus, and the blue-breasted quail, Coturnix chinensis. Conservation priorities include action on behalf of lowland forest specialists, some of which have suffered substantial reductions in the area of habitat that is potentially available. Surveys are required on the hills and mountains of Borneo, the Malay Peninsula and Sumatra, and in the Lesser Sundas. Increased resolution of vegetation data would permit more accurate prediction of species ranges. 相似文献
19.
20.
Nalini M. Nadkarni 《Oecologia》1994,100(1-2):94-97
Some of the proximate factors that would induce aboveground stems to produce adventitious roots were investigated experimentally on Senecio cooperi, a tropical cloud forest tree. Stem segments were air-layered with different treatments to promote root formation, and the number of roots initiated and rates of root growth were monitored for 20 weeks. Treatments were the application of wet epiphytes or dry epiphytes plus associated humus, sponges wetted with either water or nutrient solutions, or dry sponges. Controls (stem segments with nothing applied) were also monitored. Numbers of adventitious roots formed and rates of subsequent root growth differed among treatments. Wet epiphyte/humus and nutrient solutions were most effective in producing roots, which suggests that epiphytes and the nutrients they intercept and retain within the canopy may cue adjacent host tissue to exploit this resource. 相似文献