Classical and non-classical taxonomy: where does the boundary pass?

Rise of non-classical science during XX century had certain influence upon development of biological taxonomy. Scientific pluralism (especially normative naturalism of Laudan), contrary to positivist and early post-positivist treatments, made taxonomy acknowledged scientific discipline of its own right. The present state of some schools of taxonomy makes it possible to consider them as a part of non-classical science and constituting the non-classical taxonomy. The latter is characterized by the following most important features. Ontological substantiation of both classificatory approaches and particular classifications is requested which invalidates such formal approaches as nominalistic and phenetic (numerical) schools. This substantiation takes a form of content-wise background preferably causal models which include certain axioms and presumptions about taxonomic diversity being studied, together with its causes, and thus define initial conditions of classificatory procedures. From this viewoint, phylogenetic classificatory approach is the most developed part of non-classical taxonomy. The entire taxonomic diversity is structured into several aspects of different levels of generality, each being outlined by a particular consideration aspect. The latter makes personal knowledge constituting an irremovable part of any scientific statement about taxonomic diversity, thus opposition of "objectively" and "subjectively" elaborated classifications becomes vague. Interrelation of various species concepts corresponding to its different consideration aspects is described by uncertainty relation principle. Classificatory algorithms are to be compatible with the conditions of a background model to ensure particular classifications obtained by their means are interpretable within the same model: this is provided by the correspondence principle. Classification is considered as a taxonomic hypothesis, i.e. a conjectural judgement about structure of particular fragment of taxonomic diversity considered within given consideration aspect; wich is to be forwarded and tested according to certain rules. Recognition of different aspects of taxonomic diversity makes it "legal" to elaborate several classifications of equal status, each reflecting a particular aspect of a fixed fragment of that diversity. This viewpoint makes classical ideas of the "ultimate" Natural (whatever might be its definition) or the best reference systems futile. In general, any pretension of an approach to be "the best" in reflecting taxonomic divesrity is contr-productive. Instead, elaboration of particular spectra of complementary classifications becomes the main task of non-classical taxonomy which describes in sum the entire taxonomic diversity. So, not opposition but correct mutual interpretation of such classifications and uniting them into the comprehensive picture of taxonomic diversity become focal points of non-classical taxonomy.     

民间植物分类系统与区域性物种多样性快速评估——以西双版纳傣族为例

生物多样性的快速流失 ,使传统分类工作在热带物种多样性评估中显出不足 ,而民间分类系统在区域性物种多样性快速评估中的作用已经引起人们的重视。前人对西双版纳傣族民间植物命名和分类系统已做过研究 ,该文在此基础上 ,探讨能否将这种知识用于区域性物种多样性快速评估。利用生物多样性快速编目、样方调查及民族植物学中民间访谈的方法 ,考察了三个傣族村寨原住民的植物识别能力。结果表明 ,傣族原住民的植物识别程度与其年龄呈显著正相关 ,中年以后识别能力趋于稳定 ,识别率高达 91 %以上。通过与长期在西双版纳地区工作的野外植物分类学家相比较 ,我们发现傣族原住民的植物识别率不低于分类学家 ,且所需时间比分类学家少。作者认为 ,民间植物分类系统可以用于局部地区的物种多样性快速评估。     

Pheneticism reconsidered

The pheneticist philosophy holds that biological taxa are clusters of entities united by a form of all-things-considered resemblance. This view of taxonomy has come in for almost universal criticism from philosophers, and has received little praise from biologists, over the past 30 years or so. This article defends a modest pheneticism, understood as part of a pluralist view of taxonomy. First, phenetic approaches to taxonomy are alive and well in biological practice, especially in the areas of microbiology and botany. Second, the pheneticist notion of overall similarity is defensible, and is implicitly endorsed even by those (such as Quine) usually implicated in attacks on similarity. Third, there are limited biological domains within which pheneticism’s conception of species as kinds (rather than heterogeneous individuals) remains applicable.     

It is normal for classification approaches to be diverse

It is asserted that the postmodern concept of science, unlike the classical ideal, presumes necessary existence of various classification approaches (schools) in taxonomy, each corresponding to a particular aspect of consideration of the "taxic reality". They are set up by diversity of initial epistemological and ontological backgrounds which fix in a certain way a) fragments of that reality allowable for investigation, and b) allowable methods of exploration of the fragments being fixed. It makes it possible to define a taxonomic school as a unity of the above backgrounds together with consideration aspect delimited by them. Two extreme positions of these backgrounds could be recognized in recent taxonomic thought. One of them follows the scholastic tradition of elaboration of a formal and, hence, universal classificatory method ("new typology", numerical phenetics, pattern cladistics). Another one asserts dependence of classificatory approach on the judgment of the nature of taxic reality (natural philosophy, evolutionary schools of taxonomy). Some arguments are put forward in favor of significant impact of evolutionary thinking onto the theory of modern taxonomy. This impact is manifested by the correspondence principle which makes classificatory algorithms (and hence resulting classifications) depending onto initial assumptions about causes of taxic diversity. It is asserted that criteria of "quality" of both classifications proper and classificatory methods can be correctly formulated within the framework of a particular consideration aspect only. For any group of organisms, several particular classifications are rightful to exist, each corresponding to a particular consideration aspect. These classifications could not be arranged along the "better-worse" scale, as they reflect different fragments of the taxic reality. Their mutual interpretation depends on degree of compatibility of background assumptions and of the tasks being resolved. Extensionally, classifications are compatible as much as they coincide by context and hierarchical structure of included taxa. Intentionally, typological classifications are compatible if included taxa are comparable by their diagnoses, while phylogenetic classifications are compatible if the included taxa are ascribed monophyletic status. A brief consideration is given to the "new phylogenetics" (= "genophyletics") as to a classificatory approach aimed at elaboration of parsimonious phylogenetic hypotheses based on molecular biology data and employing numerical methods of cladistic analysis. This approach is shown to borrows some phenetic ideas and revives scholastic principle of unified classificatory basis. It is supposed that, in a time, biological classification would get escaping from plethora of positivistic ideas (including those being developed by nowaday cladistics) and would assimilate (revive) more actively holistic worldview.     

Evaluating Maclaurin and Sterelny’s conception of biodiversity in cases of frequent,promiscuous lateral gene transfer

The recent conception of biodiversity proposed by James Maclaurin and Sterelny was developed mostly with macrobiological life in mind. They suggest that we measure biodiversity by dividing life into natural units (typically species) and quantifying the differences among units using phenetic rather than phylogenetic measures of distance. They identify problems in implementing quantitative phylogenetic notions of difference for non-prokaryotic species. I suggest that if we focus on microbiological life forms that engage in frequent, promiscuous lateral gene transfer (LGT), and their associated reticulated phylogenies, we need to rethink the notion of species as the natural unit, and we discover additional problems with phylogenetic notions of distance. These problems suggest that a phenetic approach based on morphospaces has just as much appeal, if not more, for microbes as they do for multi-cellular life. Facts about LGT, however, offer no new insight into the additional challenge of reconciling units and differences into a single measure of biodiversity.     

Entomopathogenic Nematodes: Biodiversity, Geographical Distribution and the Convention on Biological Diversity

This paper addresses three major issues. Firstly, molecular taxonomy and its application to elucidate the biodiversity and biogeography of entomopathogenic nematodes is considered. Accurate identification is fundamental for understanding biodiversity, and because these nematodes are morphologically conservative, molecular techniques will provide the insights necessary to develop a robust, morphologically based taxonomy. Secondly, a review of the knowledge on their biogeography and habitat specificity, including a consideration of the limitations to the available data is given. Much of the information is presented in two tables which summarize the distributions of recognized species at continental and national levels. Thirdly, this paper provides a brief consideration of the Convention on Biological Diversity and its implications for future work with entomopathogenic nematodes and biological control.     

Latitudinal gradients in the phenetic diversity of New World bat communities

Although the examination of latitudinal gradients of species richness is common, little attention has been devoted to other components of biodiversity such as phenetic diversity. Because the phenotype reflects aspects of an organism's environment, ecological relationships and evolutionary history, measures of phenetic diversity likely provide complimentary information to that of species richness, and may provide unique insights for understanding the mechanistic basis to patterns of biodiversity. Herein, we evaluate latitudinal gradients in the phenetic diversity of 32 New World bat communities. Seven morphological characters were used to estimate phenotypic variation among bat species within local communities. Principal components analysis decomposed this variation into axes of size and shape. Three measures of phenetic diversity were calculated separately for size and for shape axes. The range of species scores on a particular axis described the amount of phenetic variation encompassed by species in a community. The standard deviation of minimum spanning‐tree segment lengths described uniformity of species. Average nearest‐neighbor distances described local packing. We separately regressed these six measures on local species richness and latitude separately. Variation in species richness accounted for a significant amount of variation in each measure of phenetic diversity. Latitude also accounted for significant variation in phenetic diversity except for the standard deviation of minimum‐spanning tree segment lengths and the average nearest‐neighbor distance on the shape axis. More importantly, gradients in phenetic diversity were significantly different than would be expected as a consequence of latitudinal gradients in species richness. Nonetheless, when variation among communities regarding the richness and composition of their regional faunas was taken into consideration, differences between empirical and simulated gradients were nonsignificant. Thus, factors that determine the composition of regional faunas have a great impact on the phenetic diversity of communities and ultimately the latitudinal gradient in biodiversity.     

Concepts of taxonomy and concepts of biodiversity: the problem of interaction

There is, or there should be, an interaction between concepts of taxonomy and biodiversity. On the one hand, taxonomy develops some general and particular classificatory paradigms, which own diversity is to be taken into account to understand the nature of variety of natural kinds. On the other hand, analysis of the properties of biodiversity may put forward nontrivial problems for taxonomy that cannot be deduced directly from its own statements. From the point view of taxonomy, it is argued that the current concept of biodiversity based entirely on the species concept is deeply rooted in reductionistic view of nature. It is outdated epistemologically and should be replaced by the modern taxonomic concept of the hierarchical phylogenetic pattern. Operationally, the latter presumes a possibility for each species to be assigned a certain "phylogenetic weight", according to its phylogenetic uniqueness. From the point view of biodiversity, it is argued that the global biodiversity is a three component entity, as it includes, in addition to phylogenetic and ecological hierarchies, a biomorphic hierarchy, as well. This calls for taxonomy to elaborate the general principles of classification of biomorphs.     

生物多样性的进化原理及其保护对策

本文论述了传统进化论学说对生物多样性解释的不足,探讨用生物适化学说解释生物多样性的形成,提出生物多样性产生的表达式： B_d=∫^T_Ｏ［(G_c-m+M)·E_c-(N_t+A_p+H_f)］dt, 并以此说明制订保育它们的原则对策。     

Incongruence between cladistic and taxonomic systems

Cladistic and taxonomic treatments of the same plant group usually exhibit a mixture of congruences and incongruences. The question arises in the case of the incongruences as to which version is right and which is wrong. Many cladists believe that cladistics is a superior approach and gives the best results. There are several conceptual and methodological differences between cladistics and taxonomy that cause incongruence. One important conceptual difference is the use of different criteria for grouping: order of branching vs. similarity and difference (clades vs. taxa). Another is the policy regarding paraphyletic groups: to ban them in cladistics but ignore the ban in taxonomy. These two differences automatically lead to some incongruences. One approach is not right and the other wrong; each is operating by its own standards. However, when cladists apply the paraphyly rule to a taxonomic system and conclude that it needs revision to eliminate paraphyly, as cladists often do, they are judging the taxonomic system by a wrong standard. Several differences between the two schools in the use and handling of characters can also cause incongruence. First consider phenetic characters. Taxonomy uses a very wide range of these, whereas phenetic cladistics sets restrictions on the selection of characters, which deprive it of potentially useful evidence. Taxonomic systems generally rest on a broader empirical foundation than phenetic cladistic systems. Next, consider molecular cladistics, which is the leader in the use of DNA evidence. Two sources of incongruence between molecular cladistics and taxonomic systems can come into play here. First, the molecular evidence used in cladistics comes mainly from cytoplasmic organelles, whereas taxonomic systems are based on characters that are determined mainly by the chromosomal genome. More generally, the database in a molecular cladogram is, in itself, too narrow to serve as a foundation for an organismic classification. In cases of incongruence, the molecular evidence can be a reliable indicator of taxonomic relationships sometimes, misleading other times, and may afford no clear basis for a systematic decision. In this situation, it is helpful, indeed necessary, to integrate the molecular evidence with the phenetic evidence and bring more characters to bear on the question.     

中国栎属植物的数量分类研究

在全面衡量中国栎属49种4变种性状特征的基础上,观测了25个定性性状和18个数量性状。通过聚类分析,可以将中国栎属分为5个特征明显的表征群,即5组:麻栎组(Section Aegilops)、槲栎组(Section Quercus)、高山栎组(Section Brachylepides)、巴东栎组(Section Engleriana)和橿子栎组(Section Echinolepides)。在主成分分析中,虽然性状的累积贡献率增长不明显,前3个主成分累积贡献率仅有50.4%,但结果仍然显示出和聚类分析同样的结果。说明栎属的分类性状仍存在主要方面,只不过在演化过程中由于性状变异的多样性,产生了多个不同的表征类群。分析结果对我们解决个别有疑问种的分类地位也有启示作用。因此,数量分类方法对解决栎属组间及种间的分类问题有重要的意义。     

Some ideas for activities involving the construction of computer-based identification keys

Conserving global biodiversity depends on public awareness, hence the vital role of education and the recent thinking that biodiversity conservation should form part of a new and general scientific literacy taught in schools. A crucial aspect of biodiversity conservation is species identification. Taxonomy in general, and identification keys in particular, are often seen as boring and outdated. Indeed, curricula focused on contemporary areas of biology tend to give a low priority to taxonomy or ignore it completely. However, concern for diminishing global biodiversity has provoked a renewed interest in both traditional and more innovative identification methods, including computer-aided taxonomy.

Some ideas for applying information and communication technology (ICT) to constructing identification keysare discussed. The use of linked web pages is proposed as the most easily used and readily accessible method for Year 8 pupils (ages 12 – 13). It is suggested that there is more educational value in pupils then testing and evaluating each other's keys rather than simply using them and that to facilitate this, web-based keys can easily be exchanged via a network.

It is concluded that this approach promotes a wide range of transferable ICT skills, but applies them in the context of a current problem facing real biologists, so illustrating how computer technology is assisting biodiversity research.     

Foundations of the new phylogenetics

Evolutionary idea is the core of the modern biology. Due to this, phylogenetics dealing with historical reconstructions in biology takes a priority position among biological disciplines. The second half of the 20th century witnessed growth of a great interest to phylogenetic reconstructions at macrotaxonomic level which replaced microevolutionary studies dominating during the 30s-60s. This meant shift from population thinking to phylogenetic one but it was not revival of the classical phylogenetics; rather, a new approach emerged that was baptized The New Phylogenetics. It arose as a result of merging of three disciplines which were developing independently during 60s-70s, namely cladistics, numerical phyletics, and molecular phylogenetics (now basically genophyletics). Thus, the new phylogenetics could be defined as a branch of evolutionary biology aimed at elaboration of "parsimonious" cladistic hypotheses by means of numerical methods on the basis of mostly molecular data. Classical phylogenetics, as a historical predecessor of the new one, emerged on the basis of the naturphilosophical worldview which included a superorganismal idea of biota. Accordingly to that view, historical development (the phylogeny) was thought an analogy of individual one (the ontogeny) so its most basical features were progressive parallel developments of "parts" (taxa), supplemented with Darwinian concept of monophyly. Two predominating traditions were diverged within classical phylogenetics according to a particular interpretation of relation between these concepts. One of them (Cope, Severtzow) belittled monophyly and paid most attention to progressive parallel developments of morphological traits. Such an attitude turned this kind of phylogenetics to be rather the semogenetics dealing primarily with evolution of structures and not of taxa. Another tradition (Haeckel) considered both monophyletic and parallel origins of taxa jointly: in the middle of 20th century it was split into phylistics (Rasnitsyn's term; close to Simpsonian evolutionary taxonomy) belonging rather to the classical realm, and Hennigian cladistics that pays attention to origin of monophyletic taxa exclusively. In early of the 20th century, microevolutionary doctrine became predominating in evolutionary studies. Its core is the population thinking accompanied by the phenetic one based on equation of kinship to overall similarity. They were connected to positivist philosophy and hence were characterized by reductionism at both ontological and epistemological levels. It led to fall of classical phylogenetics but created the prerequisites for the new phylogenetics which also appeared to be full of reductionism. The new rise of phylogenetic (rather than tree) thinking during the last third of the 20th century was caused by lost of explanatory power of population one and by development of the new worldview and new epistemological premises. That new worldview is based on the synergetic (Prigoginian) model of development of non-equilibrium systems: evolution of the biota, a part of which is phylogeny, is considered as such a development. At epistemological level, the principal premise appeared to be fall of positivism which was replaced by post-positivism argumentation schemes. Input of cladistics into new phylogenetics is twofold. On the one hand, it reduced phylogeny to cladistic history lacking any adaptivist interpretation and presuming minimal evolution model. From this it followed reduction of kinship relation to sister-group relation lacking any reference to real time scale and to ancestor-descendant relation. On the other hand, cladistics elaborated methodology of phylogenetic reconstructions based on the synapomorphy principle, the outgroup concept became its part. The both inputs served as premises of incorporation of both numerical techniques and molecular data into phylogenetic reconstruction. Numerical phyletics provided the new phylogenetics with easily manipulated algorithms of cladogram construing and thus made phylogenetic reconstructions operational and repetitive. The above phenetic formula "kinship = similarity" appeared to be a keystone for development of the genophyletics. Within numerical phyletics, a lot of computer programs were elaborated which allow to manipulate with evolutionary scenario during phylogenetic reconstructions. They make it possible to reconstruct both clado- and semogeneses based on the same formalized methods. Multiplicity of numerical approaches indicates that, just as in the case of numerical phenetics, choice of adequate method(s) should be based on biologically sound theory. The main input of genophyletics (= molecular phylogenetics) into the new phylogenetics was due to completely new factology which makes it possible to compare directly such far distant taxa as prokaryotes and higher eukaryotes. Genophyletics is based on the theory of neutral evolution borrowed from microevolutionary theory and on the molecular clock hypothesis which is now considered largely inadequate. The future developments of genophyletics will be aimed at clarification of such fundamental (and "classical" by origin) problems as application of character and homology concepts to molecular structures. The new phylogenetics itself is differentiated into several schools caused basically by diversity of various approaches existing within each of its "roots". Cladistics makes new phylogenetics splitted into evolutionary and parsimonious ontological viewpoints. Numerical phyletics divides it into statistical and (again) parsimonious methodologies. Molecular phylogenetics is opposite by its factological basis to morphological one. The new phylogenetics has significance impact onto the "newest" systematics. From one side, it gives ontological status back to macrotaxa they have lost due to "new" systematics based on population thinking. From another side, it rejects some basical principles of classical phylogenetic (originally Linnean) taxonomy such as recognitions of fixed taxonomic ranks designated by respective terms and definition of taxic names not by the diagnostic characters but by reference to the ancestor. The latter makes the PhyloCode overburdened ideologically and the "newest" systematics self-controversial, as concept of ancestor has been acknowledged non-operational from the very beginning of cladistics. Relation between classical and new phylogenetics is twofold. At the one hand, general phylogenetic hypothesis (in its classical sense) can be treated as a combination of cladogenetic and semogenetic reconstructions. Such a consideration is bound to pay close attention to the uncertainty relation principle which, in case of the phylogenetics, means that the general phylogenetic hypothesis cannot be more certain than any of initial cladogenetic or semogenetic hypotheses. From this standpoint, the new phylogenetics makes it possible to reconstruct phylogeny following epistemological principle "from simple to complex". It elaborates a kind of null hypotheses about evolutionary history which are more easy to test as compared to classical hypotheses. Afterward, such hypotheses are possible to be completed toward the classical, more content-wise ones by adding anagenetic information to the cladogenetic one. At another hand, reconstructions elaborated within the new phylogenetics could be considered as specific null hypotheses about both clado- and semogeneses. They are to be tested subsequently by mean of various models, including those borrowed from "classical" morphology. The future development of the new phylogenetics is supposed to be connected with getting out of plethora of reductionism inherited by it from population thinking and specification of object domain of the phylogenetics. As the latter is a part of an evolutionary theory, its future developments will be adjusted with the latter. Lately predominating neodarwinism is now being replaced by the epigenetic evolutionary theory to which phylistics (one of the modern versions of classical phylogenetics) seems to be more correspondent.     

中国生物多样性保护的变革性转变及路径

全球正在经历第六次物种大灭绝。为了应对生物多样性丧失速率日益加快的严峻挑战, 《生物多样性公约》第十届缔约方大会通过了《生物多样性战略计划》(2011-2020年)及20项爱知生物多样性目标。然而, 2019年IPBES全球评估报告表明, 大部分爱知目标可能无法在2020年实现, 因此, 自然保护需要变革性转变。中国虽然在生物多样性保护方面取得了巨大成就, 提出了系统完整的生态文明制度及建立“以国家公园为主体的自然保护地体系”的目标, 并通过绿盾行动和环保督察提升了生物多样性保护的重要性, 陆地自然保护地覆盖率也已达到18%, 但仍未有效遏制生物多样性下降的趋势, 物种濒危程度持续加剧。尽管生态文明一系列改革已经做出了变革性转变, 中央层面大力推行生物多样性“主流化”的相关政策, 通过机构改革初步解决了自然保护地“九龙治水”的问题, 在国土空间规划和生态保护红线划定中强调了生物多样性保护的重要性, 但是, 生物多样性保护仍然缺乏系统性的解决策略, 需要在不同层面进一步落实“主流化”, 建立完整的法律体系和统一规范高效的保护机制, 保障保护资金, 明确生物多样性在生产、生活空间中的地位, 打通自然保护成果与经济利益的转化渠道。因此, 中国的生物多样性保护应当借助生态文明建设的历史性机遇, 在保护意识、空间布局和保护行动3个方面充分实现变革性的转变, 借助五位一体总体布局, 采用系统化的解决方法, 进一步整合法律、行政、市场、技术和社会等五方面力量, 提出具体的实现路径, 实现保护意识主流化、保护利用统筹化和保护行动全民化等三方面变革性的转变, 形成高效一体化的机制, 以实现“人与自然和谐相处”的生物多样性保护理想状态。     

A multigene molecular assessment of cryptic biodiversity in the iconic freshwater blackfishes (Teleostei: Percichthyidae: Gadopsis) of south‐eastern Australia

Freshwater biodiversity is under ever increasing threat from human activities, and its conservation and management require a sound knowledge of species‐level taxonomy. Cryptic biodiversity is a common feature for aquatic systems, particularly in Australia, where recent genetic assessments suggest that the actual number of freshwater fish species may be considerably higher than currently listed. The freshwater blackfishes (genus Gadopsis) are an iconic group in south‐eastern Australia and, in combination with their broad, naturally divided distribution and biological attributes that might limit dispersal, as well as ongoing taxonomic uncertainty, they comprise an ideal study group for assessing cryptic biodiversity. We used a multigene molecular assessment including both nuclear (51 allozyme loci; two S7 introns) and matrilineal markers (cytb) to assess species boundaries and broad genetic substructure within freshwater blackfishes. Range‐wide examination demonstrates the presence of at least six candidate species across two nominal taxa, Gadopsis marmoratus and Gadopsis bispinosus. Phylogeographical patterns often aligned to purported biogeographical provinces but occasionally reflected more restricted and unexpected relationships. We highlight key issues with taxonomy, conservation, and management for a species group in a highly modified region. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 521–540.     

An evaluation of the systematic value of skull morphology in the Trimeresurus radiation (Serpentes: Viperidae: Crotalinae) of Asian pitvipers

Trimeresurus (in its widest sense) is a very diverse and widespread radiation of Asian pitvipers, which has been subject to numerous taxonomic revisions, some of which have been based on characteristics of the skull. In order to evaluate the taxonomic utility of such characters, we conducted a comparison of the skulls of 57 specimens representing nine genera, and two currently unassigned species that are very closely related to each other. A canonical variate analysis reveals three distinct phenetic groups: the Protobothrops group, a group containing Ovophis monticola , ' Ovophis ' okinavensis , and ' Trimeresurus ' gracilis , and finally a group comprising the remaining species and characterized by considerable overlap between most genera with the exception of the monotypic Peltopelor and Himalayophis . Agreement between phenetic similarity based on skull characteristics and phylogenetic relationships based on molecular evidence varies between different groups: the morphological similarity of the skull of Protobothrops sieversorum to the other Protobothrops species is congruent with their recent synonymization while the phenetic similarity among the species within the second group does not reflect current molecular phylogenetic relationships and indicates that convergent or parallel evolution may be responsible for at least some of the phenetic similarity detected among skulls of the Asian pit vipers examined. A test of phylogenetic independence, however, indicates that there is still a significant phylogenetic signal that can be recovered from several skull characteristics. Thus, we conclude that skull morphology can contribute to an overall understanding of pitviper taxonomy, but that it would be unwise to rely on skull characteristics alone.     

Assessing conservation status and trends for the world��s butterflies: the Sampled Red List Index approach

Red List Indices provide a method for assessing global trends in species?? conservation status, and for monitoring progress towards achieving conservation targets (for example, commitments under the Convention on Biological Diversity). Red List Indices are based on categorization of taxa in terms of their threat status using information on, for example, current and projected abundances, distributions, and threats. Global assessments have now been undertaken for a suite of well-known vertebrate taxa. However, highly diverse invertebrate taxa are currently very poorly represented in such assessments, and there is a danger that their threats and their utility as biodiversity indicators will be overlooked. Unlike most invertebrates, butterflies are relatively well-known globally. We describe ongoing efforts to incorporate butterflies into the Red List Index process. Because of high species richness (approximately 15,000 Papilionoidea globally) a comprehensive assessment is not feasible. Instead, we apply a ??Sampled Red List Index?? approach which draws on a subset of 1,500 focal taxa. We illustrate the process and the challenges (particularly taxonomic issues and issues of data deficiency) using a variety of case studies. The information provided should be relevant to other researchers seeking to apply the Red List Index approach to invertebrates and other diverse but poorly studied taxa.     

Methods of classifying nemerteans: an assessment

Phenetic, cladistic and phyletic methods of classifying animals are discussed with particular reference to nemerteans. It is concluded that phenetic (numerical) taxonomy is particularly inapplicable to any group of invertebrates for which well defined character differences are relatively few, whilst both the phenetic and cladistic methods fail through their fundamental assumption that convergent evolution is a rare occurrence. Terrestrial and freshwater nemerteans especially demonstrate convergent evolution in many ways; cladistic classifications proposed for these animals are therefore untenable. Convergence is shown to be a common occurrence in other nemerteans also. It is concluded that because the traditional phyletic approach does not implicitly assume that resemblances between organisms are more likely to be due to common ancestry than to convergence, it is far more likely to reveal true evolutionary relationships between taxa.