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1.
A method based on morphological characters is proposed to evaluate biological diversity of a sockeye salmon population. In all samples, morphological diversity of males is greater than that of females. In addition, the inter-annual dynamics determined on the basis of separate morphological characters differs in individuals of different sex. The necessity of studying biological diversity for preserving population homeostasis is also considered.  相似文献   

2.
本文首次提出了生物性状的系统分析理论,指出了多元分析在生物性状应用研究中,应使统计分析模型适应于生物性状之间的相互作用规律,而不应是使生物性状适应于统计分析模型。生物性状多元分析时,统计上或任何人为增加或减少某些性状将影响生物性状之间的相互作用的大小,并得出不符合生物规律的错误结论,只有根据生物性状的系统理论分析生物性状之间的相互作用关系,才能准确评价各性状之间的相互作用大小。  相似文献   

3.
4.
殷宗俊  张勤 《遗传》2006,28(5):578-582
动物中有许多重要的离散性状,与常规的数量性状类似,其遗传基础受多基因控制并受到环境因子的修饰。由于多基因离散性状的表型特殊性,利用常规的QTL连锁分析方法很难获得理想的统计效果,相应地发展了许多基于广义线性模型框架内的非线性方法。本文就目前离散性状的QTL连锁分析方法作简要综述,并对可预期的改进方法进行了展望。  相似文献   

5.
根据1988年11月至1991年3月间野外收集的资料,本文记述了云南抚仙湖鱇(鱼良)白鱼的空间分布、食性和繁殖生物学特性。在此基础上,本文首次尝试从进化的观点出发,结合湖泊环境的演变历史深入一步分析了鱇(鱼良)白鱼生物学特性的形成和演化。研究结果表明,鱇(鱼良)白鱼喜在山泉水口等流水环境产卵及幼体喜居湖泊沿岸浅水区等生活习性属较原始的性状,提示了鱇(鱼良)白鱼的祖先是营溪流生活的鱼类。成体喜居湖泊敞水区中上层、营滤食为主、繁殖季节较长、各产卵群体的产卵时间间隔有明显规律性、繁殖力较低、性比较悬殊等特性则属较特化的性状,这些较特化性状的形成与湖泊环境的总体演变过程密切相关。在性状分析的基础上还进一步探讨了生物学特性的适应意义。  相似文献   

6.
Summary In this article we argue that an organismic perspective in character identification can alleviate a structural deficiency of mathematical models in biology relative to the ones in the physical sciences. The problem with many biological theories is that they do not contain the conditions of their validity or a method of identifying objects that are appropriate instances of the models. Here functionally important biological characters are introduced as conceptual abstractions derived within the context of an ontologically prior object, such as a cell or an organism. To illustrate this approach, we present an analytical method of character decomposition based on the notion of the quasi-independence of traits. Two cases are analyzed: context dependent units of inheritance and a model of character identification in adaptive evolution. We demonstrate that in each case the biological process as represented by a mathematical theory entails the conditions for the individualization of characters. Our approach also requires a conceptual re-orientation in the way we build biological models. Rather than defining a set of biological characters a priori, functionally relevant characters are identified in the context of a higher level biological process.  相似文献   

7.
A branch and bound algorithm is described for searching rapidlyfor minimal length trees from biological data. The algorithmadds characters one at a time, rather than adding taxa, as inprevious branch and bound methods. The algorithm has been programmedand is available from the authors. A worked example is givenwith 33 characters and 15 taxa. About 8 x 1012 binary treesare possible with 15 taxa but the branch and bound program findsthe minimal tree in <5 min on an IBM PC. Received on January 15, 1987; accepted on February 23, 1987  相似文献   

8.
Most biological homologues involve comparison of single characters in two or more taxa. It is possible, however, to recognize homologous characters between two or more taxa that involve the transformation of one character into many characters or many characters into one character. This type of homology is recognized as field homology and it has been widely used in comparative neuroanatomy. The emergence of the cladistic analysis of embryonic stages in the development of neural characters, however, strongly suggests that field homology is a meaningless concept. When it appears necessary to recognize field homologues, it is because comparisons are being made at an inappropriate level within a given biological hierarchy. Furthermore, recognition of field homologues restricts evolutionary mechanisms to a single mechanism of parcellation as defined by Ebbesson.  相似文献   

9.
A gametic model of quantitative character dynamics is introduced that fills the gap between the two existing models: genic and zygotic/phenotypic. In this model, a gamete is treated as the elementary unit of evolution, all biological processes at the levels below gametic remain unspecified, and a gamete is characterized by its effect on the quantitative character rather than by the genotype. The hereditary and developmental processes are accounted for in a generalized form by gametogenetic and developmental functions defined for a pair of gametic effects representing an individual. A parameterization of these functions is suggested that imposes constraints on the heredity of quantitative characters similar to the constraints imposed by traditional genic models. It is shown that this parameterization can be derived for some polygenic additive models. General expressions for the dynamics of the mean and variance of additive quantitative characters are obtained, and the dynamics under random mating for sex-independent, sex-controlled, and sex-linked characters are considered. Comparisons with the dynamics predicted by genic models are made.  相似文献   

10.
A phylogeny of the families of Scarabaeoidea (Coleoptera)   总被引:1,自引:1,他引:0  
Abstract. A study, based on examination of thirteen scarabaeoid families, was made of 134 adult and larval characters from the following character suites: 105 adult characters of the antennae, eye, epipharynx, mandible, maxillae, labium, tentorium, trochantin, procoxae, mesocoxae, mesothoracic spiracles, hind wing articulation, hind wing base, hind wing venation, hind wing folding, abdominal sternites, abdominal spiracles, male genitalia, ovarioles and karyotype; twenty larval characters of the antennae, fronto-clypeal suture, stemmata, labial palpi, maxillae, mandibles, legs, stridulatory apparatus, spiracles and ecdysial process; and nine adult and larval biological characters. In order to assess the reliability of different characters in resolving scarabaeoid family relationships, six data sets were subjected to cladistic analysis: the total evidence character set (134 characters), restricted adult character set (thirty-two characters, not including those of the wings), wing character set (seventy-three characters), larval character set (twenty characters), biological character set (nine characters) and re-coded Howden (1982) character set (thirty-nine characters). The complete character set and wing character set both produced phylograms with all nodes resolved; the restricted adult data set, larval data set, Howden (1982) data set and biological data set produced phylograms with diminishing levels of node resolution. The reconstructed phylogeny, from the preferred phylogram of the total evidence character set, shows that the Scarabaeoidea comprises three major lineages; a glaresid, passalid and scarabaeid lineage. The glaresid lineage consists only of the Glaresidae. The passalid lineage comprises two major lines; a glaphyrid line (containing Glaphyridae, Passalidae, Lucanidae, Diphyllostomatidae, Trogidae, Bolboceratidae and Pleocomidae) and a geotrupid line (containing Geotrupidae, Ochodaeidae, Ceratocanthidae and Hybosoridae). The scarabaeid lineage contains those taxa traditionally included within the Scarabaeidae (Aphodiinae, Scarabaeinae, Orphninae, Melolonthinae, Acoma, Chasmatopterinae, Hopliinae, Oncerinae, Rutelinae, Dynastinae, Trichiinae, Cetoniinae and Valginae).  相似文献   

11.
谐波分析在遗传学中的应用探讨   总被引:1,自引:0,他引:1  
李晓方 《遗传学报》1991,18(6):545-551
本文以油菜籽粒蛋白质和油分的积累过程为例,探讨了谐波分析描述生物指标量变过程的可能性。通过分解出指标动态变化过程中的遗传分量,了解特定指标表现型过程的遗传规律。初步认为油菜籽粒蛋白质和油份积累的过程中,有两个显著优势的简谐波,并表现一定的遗传特点。表明谐波分析对于揭示生物指标表现型过程的遗传规律,将有一定的实际意义和提供了一种新的探索途径。  相似文献   

12.
In the course of haematological and biological investigations among Aymara and Quechua populations in Bolivia, an anthropological study of the erythrocytary respiratory function was carried out on the two groups at two altitudes: 3,600 m and 450 m. A difference in the intensity of the biological variations of the two populations is observed at high altitude. In the Quechuas, as in any lowland native, the adaptative phenomena are totally and quickly reversible. In the Aymaras, we detected the existence of more marked haematological and biochemical characters: moderate polycythemia, hyperhaemoglobinemia, microcytosis, metabolical hyperactivity with accumulation of 2-3 di-phosphoglycerate and ATP, and methaemoglobinemia with a drop in the activity of the methaemoglobin reductases. The Aymaras preserve some of those characters (methaemoglobinemia excepted) when they settle in lowlands.  相似文献   

13.
Under brief consideration is the problem of primary or secondary status of the judgments about taxa relative to the judgments about characters in the biological classifications. The following formal definition of taxonomic system (classification) TS is provided: TS = BT[T, C(t), R(t), R(c), R(tc)], where BT is a biological theory constituting content-wise background of the system, T is a set of taxa, C(t) is a set of taxonomic characters, R(t) is a set of relationships among taxa (similarity, kinship, etc.), R(c) is a set of relationships among characters (homology, etc.), and R(tc) is a set of correspondences among taxa and characters. The latter correspondences may be complete or incomplete. At ontological level, there two basical traditions exist in biological systematics regarding R(tc) according to which the biological diversity is patterned either as a set of groups of organisms (taxa) or as a set of their properties (characters). In the first case, taxon is "primary" relative to character (in cladistics); in its opposite, character is "primary" relative to taxon (in scholasticism, classical typology, classical phylogenetics). At epistemological level, incompleteness of the taxon-character correspondence makes classificatory procedure iterative and taxonomic diagnoses context-dependent. The interative nature of classificatory procedure makes the "primary" or "secondary" status of both taxa and characters relative and alternating. This makes it necessary to introduces a kind of uncertainty relation in biological systematics which means impossibility of simultaneous definition of both extensional and intentional parameters of the taxonomic system at each step of classificatory iterations.  相似文献   

14.
Morphological phylogenetics of termites (Isoptera)   总被引:6,自引:0,他引:6  
Isoptera (termites) are an ecologically important order, with both a high abundance and biomass in tropical ecosystems. However, there have been few phylogenetic hypotheses for termites, and we present here the first comprehensive cladistic analysis for the group. We analysed relationships between all seven termite families, including representatives of all known feeding group, plus a number of systematically critical taxa. Termite species richness is biased towards the higher termites (Termitidae), and our taxon sampling reflects this. Our analysis was based essentially on morphological characters (96 workers, 93 soldiers) plus seven biological characters. The cladistic analysis gave four equally parsimonious trees, representing two islands of topologies. The strict consensus tree is fully resolved for the higher termites, but less so for the lower termites. Overall there is low statistical support for the suggested topology, and this can be explained by the high incongruence between the data sets (worker, soldier and biological). This study highlights the particular problems of coding morphological characters in social insects with multiple castes. Without the input of additional data sets, e.g. alates, biological, behavioural and molecular, it will not be possible to obtain a well-supported termite phylogeny.  相似文献   

15.
水螨群总科阶元系统发育的支序分析 (蜱螨亚纲:水螨群)   总被引:1,自引:0,他引:1  
金道超 《昆虫学报》2000,43(3):309-317
对水螨群9总科进行了系统发育分析,支序分析选用了23个形态学特征和3个生物学特征。据分析结果所揭示的9总科间的系统发育关系和姐妹群关系,将水螨群9总科划分为5类:拟水螨类,含冥绒螨总科;始水螨类,含溪螨总科;真水螨类,含古水螨类和新水螨类;古水螨类,含水螨总科、盾水螨总科和皱喙螨总科;新水螨类,含刺触螨总科、腺水螨总科、湿螨总科和雄尾螨总科。类间姐妹群关系为:拟水螨类与始水螨类+真水螨类为姐妹群,始水螨类与真水螨类(古水螨类+新水螨类)为姐妹群,古水螨类与新水螨类为姐妹群。该文还就所提出的水螨群5类9总科的阶元排列建议与已有的观点进行了比较。  相似文献   

16.
A numerical taxonomic study of a graft chimaera is presented. This was made with the primary aim of elucidating the phonetic relationships between the chimaera and the two parents, but also illustrates some points concerning the weighting of characters and congruence between different sets of characters.
Branches were used as Operational Taxonomic Units, three of each of the biological kinds. The different branches of each kind were highly similar, with the chimaera being the most variable. Phonetically, the chimaera lay well offset from the line joining the parents, but otherwise about midway. Analyses made with characters determined mainly by one parent or the other showed that there is considerable interaction between the parental genotypes to yield the phenotype of the chimaera.
These relationships are much the same whether based on spatial or non-spatial quantitative characters, provided that the values are standardized; otherwise size and shape differences may be misleading. Qualitative characters can give rise to difficulties in such work, though they had little effect in the present example. The findings are discussed in relation to gene dominance.  相似文献   

17.
The notion that two characters evolve independently is of interest for two reasons. First, theories of biological integration often predict that change in one character requires complementary change in another. Second, character independence is a basic assumption of most phylogenetic inference methods, and dependent characters might confound attempts at phylogenetic inference. Previously proposed tests of correlated character evolution require a model phylogeny and therefore assume that nonphylogenetic correlation has a negligible effect on initial tree construction. This paper develops "tree-free" methods for testing the independence of cladistic characters. These methods can test the character independence model as a hypothesis before phylogeny reconstruction, or can be used simply to test for correlated evolution. We first develop an approach for visualizing suites of correlated characters by using character compatibility. Two characters are compatible if they can be used to construct a tree without homoplasy. The approach is based on the examination of mutual compatibilities between characters. The number of times two characters i and j share compatibility with a third character is calculated, and a pairwise shared compatibility matrix is constructed. From this matrix, an association matrix analogous to a dissimilarity matrix is derived. Eigenvector analyses of this association matrix reveal suites of characters with similar compatibility patterns. A priori character subsets can be tested for significant correlation on these axes. Monte Carlo tests are performed to determine the expected distribution of mutual compatibilities, given various criteria from the original data set. These simulated distributions are then used to test whether the observed amounts of nonphylogenetic correlation in character suites can be attributed to chance alone. We have applied these methods to published morphological data for caecilian amphibians. The analyses corroborate instances of dependent evolution hypothesized by previous workers and also identify novel partitions. Phylogenetic analysis is performed after reducing correlated suites to single characters. The resulting cladogram has greater topological resolution and implies appreciably less change among the remaining characters than does a tree derived from the raw data matrix.  相似文献   

18.
郭顺星  王秋颖 《菌物学报》2001,20(3):408-412
通过对不同菌株特性及作用研究,筛选出了适应性强、能显著提高天麻种子发芽率及产量的优良菌株石斛小菇(Mycena dendrobii)。该菌株伴播天麻种子后,种子发芽率高达84.18% 、播后1.5年天麻鲜产达16Kg / m2。其优良特性在实验室和天麻大面积栽培推广中得到了证实。  相似文献   

19.
为了开发利用天敌资源防治害虫,科学而客观地评价肿腿蜂对蛀干害虫的控害作用,研究了松脊吉丁肿腿蜂(Sclerodermus sp.)对松褐天牛3龄幼虫的功能反应,建立了肿腿蜂类寄生蜂室内控害效能评价体系,并证明了其可行性。该评价体系包括供试虫源标准、寄生蜂生物学与寄生行为学观察、寄生蜂对寄主的功能反应和寻找寄主效应以及寄生蜂的忠岐指数(Y)4个部分。研究结果表明:松脊吉丁肿腿蜂具有较强的控害潜力,单头雌成虫能防治3—4头松褐天牛3龄幼虫,21d内最多可致死9.07头寄主幼虫;寄主密度对单头寄生蜂寄生作用功能反应的测定结果与对寄生作用寻找效应的测定结果以及对产卵量影响的测定结果一致;综合评价该蜂对松褐天牛3龄幼虫控制效能,释放比为1∶1(即1头肿腿蜂雌蜂:1头3龄松褐天牛幼虫)时最高,其忠岐指数Y为39.63,这可能是肿腿蜂类天敌特有的抚幼习性所致,结论也与寄生蜂生物学特性及寄生行为学观察结果相同。研究结论证明该评价体系是稳定可靠的。评价体系在利用天敌昆虫生物防治害虫时为筛选最佳寄生性天敌种类提供了可行的方法和依据。  相似文献   

20.
罗焕荣   《广西植物》1988,(2):203-205
<正> 甘木通(Clematis filamentosa Dunn)又称丝铁线莲,为多年生常绿木质藤本植物。经临床验证,为对心血管疾病有显著疗效的植物新药,具有高度经济价值。为迅速推广繁殖甘木通新药源,现将它的生物学特性资料整理如下,供各地引种栽培参考。  相似文献   

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