藏马鸡分类地位和马鸡属系统进化问题的探讨

藏马鸡的分类地位问题以及马鸡属内各物种的系统进化关系,一直存在着较大的争议。本文以线粒体DNA细胞色素b基因的部分序列作为遗传标记,对藏马鸡的分类地位和马鸡属的系统进化问题做了进一步探讨。结果表明：藏马鸡更适合作为白马鸡的一个亚种;蓝马鸡与褐马鸡亲缘关系相对较近,而与白马鸡较远;白马鸡是马鸡属内较为原始的类型。     

马鸡属鸟类的系统发育关系

马鸡属（Crossoptilon）为我国鸟类的特有属,隶属于鸡形目（Galliformes）雉科（Phasianidae）（郑作新等,1978）。其中褐马鸡（C．mantchuricum）为我国Ⅰ级重点保护动物和全球易危物种,藏马鸡（C．harmani）、白马鸡（C．crossoptilon）及蓝马鸡（C．auritum）为国家Ⅱ级重点保护动物（郑光美、王岐山,1998;I-UCN,2004）。就分布而言,藏马鸡生活于喜马拉雅山东北麓和念青唐古拉山之间;白马鸡见于云南西北部、四川西部、西藏东部以及青海南部;蓝马鸡分布于青海东部、东北部、甘肃西北部及南部、四川西北部以及宁夏贺兰山地;褐马鸡分布于山西西北部、陕西省黄龙山、河北西北部及北京门头沟地区（郑作新等,1978;徐振武等,1998）。     

蓝马鸡

蓝马鸡属于鸡形目Galliformes雉科Phasianidae的马鸡属Crossoptilon,是我国特产。马鸡在我国共有三种: 1、褐马鸡(角鸡、鸡)Crossoption mantchuricumSwinhoe分布在山西北部、河北北部和西北部。 2、蓝马鸡(马鸡、松鸡)Crossoptilon auritum(Pallas)分布在青海东北部、甘肃西部。 3、藏马鸡或称白马鸡Crossoptilon crossoptilon(Hodgson)有五亚种。分布在西藏东南与昌都地区西南部、青海南都、四川西部及云南。 送三种马鸡可依下列检索表加以区别:     

西藏藏马鸡生态初步观察

藏马鸡Crossoptilon crossoptilon因分布于青藏高原而得名,藏语叫“夏娃”即白鸡,尚有白马鸡、雪鸡、白雉等名称。 本篇资料是根据1976年5—9月参加中国     

用等电聚焦技术对三种马鸡亲缘关系的研究

本文用0.5mm薄层等电聚焦电泳技术对三种马鸡的卵清蛋白进行了比较分析。电泳谱和扫描结果表明,藏马鸡和蓝马鸡的亲缘关系比褐马鸡更近些。而且地理分布、骨骼和化石材料方面的分析结果和等电聚焦的结果是一致的。     

三种马鸡的核型及染色体G-带带型

采用外周血淋巴细胞培养和NaOH显带的方法制备了白马鸡、蓝马鸡和褐马鸡的核型与染色体G－带带型。结果表明：3种马鸡的核型基本相同,2n=82,有7对大染色体,其余为微小染色体;Z染色体为第4对大染色体,W染色体的长度介于第6、7对大染色体之间;除第1对大染色体为m型、Z染色体为sm型外,其余的染色体均为t型,3种马鸡染色体G－带带型表现出较明显的差异,7对大染色体中,有6对大染色体的G－带带型有差异,利用数值分类学方法计算3种马鸡G－带带型的相似性系数并进行聚类分析,结果表明,蓝马鸡与褐马鸡新缘关系较近,二者与白马鸡的新缘关系较远。     

我国马鸡属三种的生态调查暨亲缘关系的研讨

褐马鸡Crossoptilon mantchuricum、藏马鸡Crossoptilon crossoption和蓝马鸡Crossoptilon auritum隶属于鸡形目Galliformes、雉科Phasianidae、马鸡属Crossoptilon,是我国雉科鸟类中的特有属。其中褐马鸡和藏马鸡已被列入世界濒危物种(King,1981)。褐马鸡属于国家一级保护动物,后两者为国家二级保护动物。1982—85年在河北、山西、四川、云南等省进行三种马鸡的野外考察。现就其生态学进行比较分析并探讨其亲缘关系。地理分布及垂直分布一、地理分布(图1)褐马鸡见于山西省北部,河北省西北部,分布范围狭小,且与其他两种马鸡间断分布。蓝…     

藏马鸡(封面说明)

藏马鸡(Crossoptilos crossoptilon)过去通称“白马鸡”,属鸟纲、雉科。雌雄体羽颜色相似,体重约2-3公斤。通体大都白色,头侧绯红,头顶具黑色短羽,耳羽簇白色,向后延长成短角状。尾羽特长,尾端具紫色光泽。为典     

蓝马鸡,褐马鸡及其杂种蛋白质聚焦电泳观察

本文比较了在笼养情况下,蓝马鸡、褐马鸡及杂种的形态和红细胞内的血红蛋白（Ｈｂ）、乳酸脱氢酶和苹果酸脱氢酶（ＬＤＨ和ＭＤＨ）,血浆中的淀粉酶和酯酶（Ａｍｙ和Ｅｓ）的聚焦电泳图谱。结果指出ＬＤＨ、ＭＤＨ和Ｅｓ同工酶在三种鸟之间差别不明显;而Ｈｂ和Ａｍｙ表现出较显著的差异;杂种不管在电泳图谱方面,还是在形态方面都介于蓝马鸡和揭马鸡之间。     

褐马鸡生态和生物学研究

褐马鸡(Xrossoptilon mantchuricum)生态生物学研究是“中国珍稀濒危雉类生态和生物学研究”课题的部分工作,该课题组是在本所郑作新教授领导下进行的。 马鸡属(Crossoptilon)是我国特产属。该属有褐马鸡、蓝马鸡(Crossoptilon auritum)和藏马鸡(Crossoptilon crossoptilon)等3种。 褐马鸡别名角鸡、褐鸡,古代称鹃,是我国特有的珍稀濒危的一类保护动物(图版Ⅰ:1)。 古时从汉武帝起(公元前156—87年)就有武将戴鹖冠之制以识其勇,一直到了清代,不用鹖冠而改用蓝翎和花翎的制度,但依旧沿用鹖羽。从上面历史记载,表示由于褐马鸡具有斗死乃止的本性,历代帝王就利用它的尾羽来激发武将的斗志。     

中国特产雉类—褐马鸡,藏马鸡和蓝马鸡卵壳的电镜观察

迄今为止,在国内有关野生鸟类卵壳的超微结构报道尚少。我们对中国特产鸡类——三种马鸡卵壳的表皮、气孔、木栅层、锥体层、乳头结、壳膜和基帽进行了扫描巨镜观察,并对结果进行了比较、讨论。认为三种马鸡不同结构的形态,对研究它们的亲缘关系提供了新的价值。     

壳斗科原始植物轮叶三棱栎在云南西双版纳的发现及其生物地理意义

于云南西双版纳发现了壳斗科植物的原始类群——轮叶三棱栎（Trigonobalanus verticillata Forman）。轮叶三棱栎被认为是栎属（Quercus L.）和水青冈属（Fagus L.）植物的祖先之一,原纪录分布于印度尼西亚和马来西亚,后来在我国海南岛被发现,其分布格局的形成一直未能合理解释。本次在云南新发现轮叶三棱栎,不仅可以解释它在海南岛的分布,也为海南岛历史上可能曾经连接着越南北部和广西西南部的假设提供了科学支持,具有重要的科研价值和生物地理学意义。     

IS FLORAL SPECIALIZATION AN EVOLUTIONARY DEAD‐END? POLLINATION SYSTEM TRANSITIONS IN RUELLIA (ACANTHACEAE)

Pollination systems frequently reflect adaptations to particular groups of pollinators. Such systems are indicative of evolutionary specialization and have been important in angiosperm diversification. We studied the evolution of pollination systems in the large genus Ruellia. Phylogenetic analyses, morphological ordinations, ancestral state reconstructions, and a character mapping simulation were conducted to reveal key patterns in the direction and lability of floral characters associated with pollination. We found significant floral morphological differences among species that were generally associated with different groups of floral visitors. Floral evolution has been highly labile and also directional. Some specialized systems such as hawkmoth or bat pollination are likely evolutionary dead-ends. In contrast, specialized pollination by hummingbirds is clearly not a dead-end. We found evidence for multiple reverse transitions from presumed ancestral hummingbird pollination to more derived bee or insect pollination. These repeated origins of insect pollination from hummingbird-pollinated ancestors have not evolved without historical baggage. Flowers of insect-pollinated species derived from hummingbird-pollinated ancestors are morphologically more similar to hummingbird flowers than they are to other more distantly related insect-pollinated flowers. Finally, some pollinator switches were concomitant with changes in floral morphology that are associated with those pollinators. These observations are consistent with the hypothesis that some transitions have been adaptive in the evolution of Ruellia.     

Testing heterochrony: Connecting skull shape ontogeny and evolution of feeding adaptations in baleen whales

Ontogeny plays a key role in the evolution of organisms, as changes during the complex processes of development can allow for new traits to arise. Identifying changes in ontogenetic allometry—the relationship between skull shape and size during growth—can reveal the processes underlying major evolutionary transformations. Baleen whales (Mysticeti, Cetacea) underwent major morphological changes in transitioning from their ancestral raptorial feeding mode to the three specialized filter-feeding modes observed in extant taxa. Heterochronic processes have been implicated in the evolution of these feeding modes, and their associated specialized cranial morphologies, but their role has never been tested with quantitative data. Here, we quantified skull shapes ontogeny and reconstructed ancestral allometric trajectories using 3D geometric morphometrics and phylogenetic comparative methods on sample representing modern mysticetes diversity. Our results demonstrate that Mysticeti, while having a common developmental trajectory, present distinct cranial shapes from early in their ontogeny corresponding to their different feeding ecologies. Size is the main driver of shape disparity across mysticetes. Disparate heterochronic processes are evident in the evolution of the group: skim feeders present accelerated growth relative to the ancestral nodes, while Balaenopteridae have overall slower growth, or pedomorphosis. Gray whales are the only taxon with a relatively faster rate of growth in this group, which might be connected to its unique benthic feeding strategy. Reconstructed ancestral allometries and related skull shapes indicate that extinct taxa used less specialized filter-feeding modes, a finding broadly in line with the available fossil evidence.     

Diet and the frequency of the alanine:glyoxylate aminotransferase Pro11Leu polymorphism in different human populations

The intermediary metabolic enzyme alanine:glyoxylate aminotransferase (AGT) contains a Pro11Leu polymorphism that decreases its catalytic activity by a factor of three and causes a small proportion to be mistargeted from its normal intracellular location in the peroxisomes to the mitochondria. These changes are predicted to have significant effects on the synthesis and excretion of the metabolic end-product oxalate and the deposition of insoluble calcium oxalate in the kidney and urinary tract. Based on the evolution of AGT targeting in mammals, we have previously hypothesised that this polymorphism would be advantageous for individuals who have a meat-rich diet, but disadvantageous for those who do not. If true, the frequency distribution of Pro11Leu in different extant human populations should have been shaped by their dietary history so that it should be more common in populations with predominantly meat-eating ancestral diets than it is in populations in which the ancestral diets were predominantly vegetarian. In the present study, we have determined frequency of Pro11Leu in 11 different human populations with divergent ancestral dietary lifestyles. We show that the Pro11Leu allelic frequency varies widely from 27.9% in the Saami, a population with a very meat-rich ancestral diet, to 2.3% in Chinese, who are likely to have had a more mixed ancestral diet. F_ST analysis shows that the differences in Pro11Leu frequency between some populations (particularly Saami vs Chinese) was very high when compared with neutral loci, suggesting that its frequency might have been shaped by dietary selection pressure.     

Biogeography and evolution of Dolichandra (Bignonieae,Bignoniaceae)

Little information on evolutionary relationships of Neotropical organisms or on the factors that have shaped the diversity currently encountered in this region is available. However, it is clear that biotic interactions and abiotic aspects have played important roles for species diversification in the region. This study focuses on Dolichandra (Bignonieae, Bignoniaceae), a clade of Neotropical lianas that is distributed broadly across different habitats and with diverse pollination and dispersal systems. We used sequences from two plastid DNA markers (ndhF and rpl32‐trnL) and one nuclear gene (PepC) to infer phylogenetic relationships in Dolichandra using parsimony and Bayesian approaches. We then used this phylogenetic framework as basis to study the biogeographic history, reconstruct the evolution of morphological characters and test the impact of morphology and environment on the diversification of the genus. More specifically, we: (1) time‐calibrate the phylogenetic tree of Dolichandra; (2) estimate the ancestral areas of the various lineages; (3) estimate the ancestral states of discrete and continuous morphological traits; (4) test for phylogenetic signal in environmental and phenotypic data; and (5) test whether morphological characters and/or niche evolution are correlated with cladogenesis. All Dolichandra spp. are monophyletic in the combined molecular phylogeny; relationships among species are generally well resolved, although poorly supported in some instances. The genus is inferred to have originated 36.43–26.23 Mya, possibly in eastern South America. Ancestral state reconstructions of continuous and discrete floral characters inferred a mixed morphology as the ancestral condition for the group. Phylogenetic signal differed between perianth and sexual whorls and gradual evolution was recovered for all traits except style length and anther length. Environmental variables showed no phylogenetic signal and a pattern of variation that was not correlated with branch length, suggesting that environmental transitions were concomitant with speciation. Dispersal is inferred to be the main driver of the differential distribution observed among species. In addition, climatic preferences and floral characters seem to have been important reproductive barriers in Dolichandra. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 403–420.     

Genetic differentiation,polyploidization and hybridization in northern EuropeanDactylorhiza (Orchidaceae): Evidence from allozyme markers

Taxa endemic to North-western Europe are rare, but the orchid genusDactylorhiza contains several species restricted to this area. Evidence from morphological and cytological studies have indicated that some species may have arisen recently and may be of hybrid origin. In the present report, I use allozymes to characterize the genomes in various species ofDactylorhiza and evaluate the possibilities for rapid evolutionary change in the genus. Allotetraploid species have evolved repeatedly from two principal diploid ancestral lineages. These lineages include extant diploid and autotetraploid species, from which allotetraploid derivatives may still arise. It is suggested that allotetraploidization dominates over introgression as speciation mechanism in the genus. The more common and widespread allotetraploid species could be characterized by their allozyme characters over considerable distances, indicating that each of them may have a unique origin and that they have spread from their ancestral populations to the present distribution areas. However, it is also possible that some allotetraploid species contain local populations that have been independently derived from the ancestral lineages.     

Phylogenetic distribution of compatible solute synthesis genes support a freshwater origin for cyanobacteria

Previous work using ancestral state reconstruction of habitat salinity preference proposed that the early cyanobacteria likely lived in a freshwater environment. The aim of this study was to test that hypothesis by performing phylogenetic analyses of the genes underlying salinity preferences in the cyanobacteria. Phylogenetic analysis of compatible solute genes shows that sucrose synthesis genes were likely ancestral in the cyanobacteria, and were also likely inherited during the cyanobacterial endosymbiosis and into the photosynthetic algae and land plants. In addition, the genes for the synthesis of compatible solutes that are necessary for survival in marine and hypersaline environments (such as glucosylglycerol, glucosylglycerate, and glycine betaine) were likely acquired independently high up (i.e., more recently) in the cyanobacterial tree. Because sucrose synthesis is strongly associated with growth in a low salinity environment, this independently supports a freshwater origin for the cyanobacteria. It is also consistent with geologic evidence showing that the early oceans were much warmer and saltier than modern oceans—sucrose synthesis alone would have been insufficient for early cyanobacteria to have colonized early Precambrian oceans that had a higher ionic strength. Indeed, the acquisition of an expanded set of new compatible solute genes may have enabled the historical colonization of marine and hypersaline environments by cyanobacteria, midway through their evolutionary history.