Phylogenetic relationships of Rotifera to other veriform taxa

Arguments concerning similarities in general structure and embryogenesis in Bdelloida (Rotifera), Platyhelminthes, and Acanthocephala are considered. Evolution of egg hatching in rotifers (i.e., loss of the embryonic egg shell) is evaluated in relation to the phylogenetic similarity of rotifers to the Neodermata. Based on this analysis, I proposed uniting Rotifera and Neodermata into superphylum Squamodermata.     

Phylogenetic influences on hormone levels across the primate order

Adrenal and gonadal hormone levels were evaluated in representative species from Prosimii, Ceboidea, Cercopithecoidea, and Hominoidea to determine if endocrine activity was influenced by phylogenetic factors. Most small-bodied New World primates had extremely high levels of cortisol, progesterone, and testosterone when compared with Old World primates. In contrast to the high hormone levels and diversity found in Ceboidea, Old World primates showed a more similar pattern of hormone secretion. Thus, this survey supports earlier reports indicating that the callitricids and smaller cebid monkeys have a distinctive hormone profile. Although higher hormone levels tended to be associated with lower body weight, this effect was not evident in all taxa, and there were many notable exceptions. When species differ from their predicted hormone levels based on phylogenetic heritage and body weight (e.g., titi monkeys), we must look for other biological factors that influence endocrine activity. © 1992 Wiley-Liss, Inc.     

Phylogenetic implications of the Crustacean nauplius

The plesiomorphic mode of crustacean development is widely accepted to be via a larva called the nauplius. Extant taxa like the Cephalocarida, Branchiopoda, Ostracoda, Mystacocarida, Copepoda, Cirripedia, Ascothoracida, Facetotecta, Euphausiacea and Penaeidea hatch from an egg as a free-living nauplius. Other crustaceans show an embryonic phase of development suggestive of a naupliar organization. Several features of the nauplius larva have been proposed as diagnostic characters for the Crustacea: a median (nauplius) eye; at least three pairs of head appendages (antennules, antennae, mandibles); a posteriorly directed fold (the labrum) extending over the mouth and a cephalic (nauplius) shield. The relationship between trilobite protaspis with at least four appendages and the crustacean nauplius remains unclear, but reports of a copepod orthonauplius with four appendages are rejected. Swimming is suggested to represent the underived mode of locomotion for the crustacean nauplius, and that naupliar swimming directly results in naupliar feeding which also is underived.     

Out of Africa? Phylogenetic relationships between Falco biarmicus and the other hierofalcons (Aves: Falconidae)

The phylogeographic history of the lanner falcon ( Falco biarmicus ) and the phylogenetic relationships among hierofalcons ( F. biarmicus , Falco cherrug , Falco jugger and Falco rusticolus ) were investigated using mitochondrial (mt) DNA sequences. Of the two non-coding mt sections tested, the control region (CR) appeared more suitable as phylogenetic marker sequence compared with the pseudo control region (ΨCR). For the comprehensive analysis samples from a broad geographic range representing all four hierofalcon species and their currently recognized subspecies were included. Moreover, samples of Falco mexicanus were analysed to elucidate its phylogenetic relationships to the hierofalcons. The sequence data indicate that this species is more closely related to Falco peregrinus than to the hierofalcons. In the DNA-based trees and in the maximum parsimony network all hierofalcons appear closely related and none of the species represents a monophyletic group. The close relationships among haplotypes suggest that the hierofalcon complex is an assemblage of morphospecies not yet differentiated in the genetic markers used in the present study and that the radiation of the four hierofalcon species took place rather recently. Based on the high intraspecific diversity found within F. biarmicus we assume an African origin of the hierofalcon complex. The observed pattern of haplotype distribution in the extant species may be due to incomplete lineage sorting of ancestral polymorphisms, and interspecific gene flow through hybridization.     

Phylogenetic reconstruction of carnivore social organizations

It is generally assumed that carnivore social organizations evolved directionally from a solitary ancestor into progressively more advanced forms of group living. Although alternative explanations exist, this evolutionary hypothesis has never been tested. Here, I used literature data and maximum likelihood reconstruction on a complete carnivore phylogeny to test this hypothesis against two others: one assuming directional evolution from a non-solitary ancestor, and one assuming parallel evolutions from a socially flexible ancestor, that is, an ancestor with abilities to live in a variety of social organizations. The phylogenetic reconstructions did not support any of the three hypotheses of social evolution at the root of Carnivora. At the family level, however, there was support for a non-solitary and socially flexible ancestor to Canidae, a socially flexible or solitary ancestor to Mustelidae, a solitary or socially flexible ancestor to Mephitidae, a solitary or group living ancestor to Phocidae, a group living ancestor to Otariidae and a solitary ancestor to Ursidae, Felidae, Herpestidae and Viverridae. There was equivocal support for the ancestral state of Procyonidae and Hyaenidae. It is unclear whether the common occurrence of a solitary ancestry at the family level was caused by a solitary ancestor at the root of Carnivora or by multiple transitions into a solitary state. The failure to support a solitary ancestor to Carnivora calls for caution when using this hypothesis in an evolutionary framework, and I suggest continued investigations of the pathways of the evolution of carnivore social organizations.     

Phylogenetic relationships of the enigmatic fern families Hymenophyllopsidaceae and Lophosoriaceae: Evidence fromrbcL nucleotide sequences

Nucleotide sequences fromrbcL were used to infer relationships of Lophosoriaceae and Hymenophyllopsidaceae. The phylogenetic positions of these two monotypic fern families have been debated, and neither group had been included in recent molecular systematic studies of ferns. Maximum parsimony analysis of our data supported a sister relationship betweenLophosoria andDicksonia, and also betweenHymenophyllopsis andCyathea. Thus, both newly-examined families appear to be part of a previously characterized and well-supported clade of tree ferns. The inferred relationships ofLophosoria are consistent with most (but not all) recent treatments. However,Hymenophyllopsis includes only small delicate plants superficially similar to filmy ferns (Hymenophyllaceae), very different from the large arborescent taxa. Nevertheless, some synapomorphic characteristics are shared with the tree fern clade. Further studies on gametophytes ofHymenophyllopsis are needed to test these hypotheses of relationship.     

Phylogenetic relationships of Cornaceae and close relatives inferred from matK and rbcL sequences

Phylogenetic relationships were inferred using nucleotide sequences of the chloroplast gene matK for members of Cornales, a well-supported monophyletic group comprising Cornaceae and close relatives. The shortest trees resulting from this analysis were highly concordant with those based on previous phylogenetic analysis of rbcL sequences. Analysis of a combined matK and rbcL sequence data set (a total of 2652 bp [base pairs]) provided greater resolution of relationships and higher internal support for clades compared to the individual data sets. Four major clades (most inclusive monophyletic groups) of Cornales are indicated by both sets of genes: (1) Cornus-Alangium, (2) nyssoids (Nyssa-Davidia-Camptotheca)- mastixioids (Mastixia, Diplopanax), (3) Curtisia, and (4) Hydrangeaceae-Loasaceae. The combined evidence indicates that clades 2 and 3 are sisters, with clade 4 sister to the remainder of Cornales. These relationships are also supported by other lines of evidence, including synapomorphies in fruit and pollen morphology and gynoecial vasculature. Comparisons of matK and rbcL sequences based on one of the most parsimonious rbcL-matK trees indicate that matK has a much higher A-T content (66.9% in matK vs. 55.8% in rbcL) and a lower transition:transversion ratio (1.23 in matK vs. 2.21 in rbcL). The total number of nucleotide substitutions per site for matK is 2.1 times that of rbcL in Cornales. These findings are similar to recent comparisons of matK and rbcL in other dicots. Variable sites of matK are almost evenly distributed among the three codon positions (1.0:1.0:1.3), whereas variable sites of rbcL are mostly at the third position (1.8:1.0 :7.5). Among- lineages rates of nucleotide substitutions in rbcL are basically homogeneous throughout Cornales, but are more heterogeneous in matK.     

Phylogenetic relationships of Argentinean Creole horses and other South American and Spanish breeds inferred from mitochondrial DNA sequences

South American horses constitute a direct remnant of the Iberian horses brought to the New World by the Spanish conquerors. The source of the original horses was Spain, and it is generally assumed that the animals belonged to the Andalusian, Spanish Celtic, Barb or Arabian breeds. In order to establish the relationship between Argentinean and Spanish horses, a portion of the mitochondrial D-loop of 104 animals belonging to nine South American and Spanish breeds was analysed using SSCP and DNA sequencing. The variability found both within and between breeds was very high. There were 61 polymorphic positions, representing 16% of the total sequence obtained. The mean divergence between a pair of sequences was 2.8%. Argentinean Creole horses shared two haplotypes with the Peruvian Paso from Argentina, and the commonest haplotype of the Creole horses is identical to one of the Andalusian horses. Even when there was substantial subdivision between breeds with highly significant Wright's Fixation Index (FST), the parsimony and distance-based phylogenetic analyses failed to show monophyletic groups and there was no clear relationship in the trees between the South American and any of the other horses analysed. Although this result could be interpreted as mixed ancestry of the South American breeds with respect to the Spanish breeds, it is probably indicating the retention of very ancient maternal lineages in the breeds analysed.     

Phylogenetic conservation of chromosome numbers in Actinopterygiian fishes

The genomes of ray-finned fishes (Actinopterygii) are well known for their evolutionary dynamism as reflected by drastic alterations in DNA content often via regional and whole-genome duplications, differential patterns of gene silencing or loss, shifts in the insertion-to-deletion ratios of genomic segments, and major re-patternings of chromosomes via non-homologous recombination. In sharp contrast, chromosome numbers in somatic karyotypes have been highly conserved over vast evolutionary timescales – a histogram of available counts is strongly leptokurtic with more than 50% of surveyed species displaying either 48 or 50 chromosomes. Here we employ comparative phylogenetic analyses to examine the evolutionary history of alterations in fish chromosome numbers. The most parsimonious ancestral state for major actinopterygiian clades is 48 chromosomes. When interpreted in a phylogenetic context, chromosome numbers evidence many recent instances of polyploidization in various lineages but there is no clear indication of a singular polyploidization event that has been hypothesized to have immediately preceded the teleost radiation. After factoring out evident polyploidizations, a correlation between chromosome numbers and genome sizes across the Actinopterygii is marginally statistically significant (p = 0.012) but exceedingly weak (R ² = 0.0096). Overall, our phylogenetic analysis indicates a mosaic evolutionary pattern in which the forces that govern labile features of fish genomes must operate largely independently of those that operate to conserve chromosome numbers.     

基于染色体计数和ITS序列初步探讨横断山区柴胡属植物(伞形科)的系统发育

横断山区是中国柴胡属Bupleurum植物的分布中心。本文对横断山区6个种2变种进行了染色体记数报道,其中4个种2变种是首次报道。对横断山区的10个种4个变种、中国北方（河北和黑龙江）的3个种的nrDNA ITS进行测序,同时从GenBank里面下载同属的来自非洲和地中海西部的16个nrDNA ITS序列数据,结合染色体数目变化结果,初步探讨了横断山区柴胡属植物的系统发育。结果表明横断山区可能是现代柴胡属植物的频度中心和多样分布中心之一。它们的祖先种可能是非洲北部的木本柴胡属植物B.fruticosum,或者是地中海西部的柴胡属植物,推测是通过中东和高加索扩散而形成的,其中与非洲南部特有种B.mundtii的亲缘关系也较近;染色体基数演化趋势是：8是较原始基数,6和7是次生基数,其染色体异基数变异和多倍化可能是物种形成、进化以及向外扩散的主要方式;在ITS系统发育树中,中国柴胡属植物染色体基数为8的种类聚为一支,染色体基数为6和7的种类聚为了一支,不支持舒璞等（1998）关于中国柴胡属的属下分类系统。结合已有的形态学、细胞学、孢粉学证据和ITS系统发育树,建议窄竹叶柴胡B.marginatum var.stenophyllum独立成种。     

The origins of graptolites and other pterobranchs: a journey from ‘Polyzoa’

The graptolites, known only from fossils, have been convincingly allied to the pterobranch hemichordates, a group of tiny, mostly colonial marine invertebrates bearing feeding arms. The phylogenetic position of pterobranchs has been subject to debate and revision for over a century. Their colonial lifestyle and feeding arms were originally seen as evidence placing them among the bryozoans, until later and more careful anatomical studies revealed more characters in common with acorn worms. Pterobranchs and acorn worms are now grouped as the phylum Hemichordata. For many decades, it was thought that pterobranchs were closer to the ancestral form of hemichordates, particularly because ‘lophophorate’ invertebrates also possess feeding arms, notably the phoronids and bryozoans, as do crinoid echinoderms. This traditional view has been challenged by recent molecular evidence. First, there is strong molecular evidence to indicate that lophophorates are very distant from hemichordates and echinoderms, in a different major branch of the animal phylogenetic tree. Therefore, similarities between the feeding structures must be due to convergent evolution. Second, there is strong evidence that hemichordates and echinoderms form a clade (Ambulacraria) within the deuterostomes, rather than hemichordates being closer to chordates. Third, there is weaker evidence that pterobranchs may be derived from acorn worms, and hence that the vermiform body plan may be ancestral within hemichordates. This suggestion warrants further testing. Here we review the evidence for these conclusions, highlight strengths and weaknesses in the data and analyses, and consider the implications for the origins of pterobranchs and graptolites.     

天门冬科广义铃兰族的染色体数目与核型进化研究

广义铃兰族包括6属200余种单子叶植物,具有较为稳定的染色体数目以及明显的核型变化,是研究植物染色体进化非常理想的类群.该研究采用常规压片法对铃兰族5个物种植物的染色体形态、数目及其核型进行了观察分析,并全面收集和整理了铃兰族所有已报道的共81种253条的染色体记录,通过综合统计、重建系统发育树,探讨铃兰族属间以及各属...     

Phylogenetic relationships of the paraphyletic ‘caprimulgiform’ birds (nightjars and allies)

In the past years, paraphyly of the traditional ‘Caprimulgiformes’ (nightjars and allies) with respect to Apodiformes (swifts and hummingbirds) has been well established, but the relationships between the five ‘caprimulgiform’ family‐level taxa remain controversial. These crepuscular or nocturnal birds differ in numerous anatomical features, and here an analysis of 69 morphological characters is performed. Except for the position of the Nyctibiidae (potoos), the topology of the single most‐parsimonious tree agrees with the results of a recently published large‐scale ‘phylogenomic’ study. Whereas molecular data support a clade including Nyctibiidae and the Steatornithidae (oilbird), potoos were shown to be the sister taxon of Caprimulgidae (nightjars) in the present analysis. A sister group relationship between Nyctibiidae and Caprimulgidae is strongly supported, both in terms of bootstrap robustness and the number of synapomorphies, and it is detailed that the morphological data are more likely to reflect the true relationships of these birds. A classification is proposed, and the term Strisores is introduced for a clade including all ‘Caprimulgiformes’ and Apodiformes. It is most parsimonious to assume a single origin of dark activity in the stem lineage of Strisores and a reversal to diurnal activity in Apodiformes. However, a fourfold origin of dark‐activity in the stem lineages of Steatornithidae, Podargidae, Aegothelidae and the Caprimulgidae/Nyctibiidae cannot be conclusively excluded with the data at hand.     

基部藓类分子系统学研究

基部藓类是稳定地处于藓类系统发育树基部的类群.它包括7纲,2亚纲,10目,10科,34属,637种.基部藓类虽然只占藓类种类的5％,但由于其内部各类群孢子体形态极为丰富,因此对于理解整个藓类植物的系统发育具有重要意义.通过对48个种(36个藓类、4个维管植物、2个角苔、4个苔类和2个藻类)的9个DNA片段(NU:26S,18S; MT:nad5,cox1; CP:rbcL,rps4,cp-LSU,cp-SSU,atpB)进行分子系统学分析,综合最大似然法(maximum likelihood)、最大简约法(most parsimony)和贝叶斯分析(Bayesian inference)方法的建树结果,理清了前人研究中存在冲突的类群之间的关系并为已确定的关系提供了更高的支持率.研究结果如下:(1)藻苔纲和泥炭藓纲互为姐妹类群,处于整个藓类的最基部;(2)黑藓纲与黑真藓纲互为姐妹类群(3)长台藓纲和具齿藓类组成单系;(4)四齿藓纲是所有具齿藓类的基部类群;(5)烟杆藓亚纲处于真藓纲的最基部,其次是短颈藓亚纲.以上结论在分子系统树上得到了很高的支持率.     

Phylogenetic relationships between two rare acacias and their common, widespread relatives in south-western Australia

Knowledge of phylogenetic relationships betweentaxa is particularly valuable for conservationmanagement of threatened taxa in anevolutionarily diverse flora such as that foundin the south-west of Western Australia. Acacia sciophanes and A. lobulata aretwo threatened species that have restricteddistributions at the edge of the range of theirwidespread relatives, A. anfractuosa andA. verricula respectively. The phylogenyof these species pairs was investigated usingRFLP analysis of cpDNA. Both restricted specieswere shown to be phylogenetically distinct.Acacia sciophanes and A. anfractuosaare sister species and display the characteristics of a relatively recent evolutionary lineage. In comparison A. lobulata shows significant divergence from A. verricula and is not closely related to the species group in which A. verricula is placed. Acacia lobulataappears to represent an ancient lineage and ismost likely a relictual species. Acaciaverricula also has characteristics of a moreancient evolutionary lineage than A.sciophanes and A. anfractuosa. Ifpriority setting processes based onphylogenetic principles were to be applied tothese species A. lobulata would have thegreater biodiversity value for conservationmanagement.     

Flavonoid relationships between the commelinaceae and related families

The Commelinaceae have been related taxonomically by several authors with the Gramineae, Cyperaceae; Juncaceae; Eriocaulaceae, Restionaceae, Zingiberaceae and Bromeliaceae. The flavonoids of these families were compared and analysed by cladistic methods. The cladogram, obtained by the Wagner groundplan-divergence method and numerical techniques, shows four possible main lines of evolution, one with flavonols as the dominant compounds (Zingiberaceae). The second line is also with flavonols but with modifications of the basic molecule (Eriocaulaceae, Restioinaceae, Bromeliaceae); a third line, characterized by the presence of tricin (Commelinaceae, Gramineae and Cyperaceae) and the fourth line, lacks $\text{C-}\text{glycosyl-flavones}$, with a high production of variously substituted flavones (Juncaceae).     

Vitamin C biosynthesis in prosimians: evidence for the anthropoid affinity of Tarsius

This report examines the taxonomic distribution of the in vitro biosynthesis of ascorbic acid in the Prosimii (Order: Primates). Liver and kidney samples of 15 prosimian taxa, including Tarsius bancanus, were quantitatively tested for the enzyme L-gulono-1,4-lactone oxidase. Liver samples from all taxa except Tarsius had substantial levels of the enzyme. Furthermore, unlike other eutherian mammals, kidney tissue from members of the family Lemuridae showed low but consistent levels of enzyme activity. The result for Tarsius, by fitting with the pattern exhibited by the monkeys, apes, and man, adds significant independent evidence for this animal's relatively close genetic relationship with the Anthropoidea.     

基于线粒体Cytb基因序列探讨中国斑翅蝗科部分种类的系统发育关系

基于斑翅蝗科14种的线粒体Cytb基因462 bp序列,使用MEGA2和PAUP4.0b软件包进行分析,显示Cytb基因序列具有明显的高A、T偏向性和距离依赖的TS/TV值.采用邻接法(NJ)、最大似然法(MP)和极似然法(ML)分别构建斑翅蝗科4亚科8属的系统发育树,不同算法构建的系统发育树均支持分为四大分支(亚科):A(绿纹蝗属)、B(束颈蝗属)、C((飞蝗属+车蝗属)+小车蝗属)、D((痂蝗属+异痂蝗属)+皱膝蝗属);红胫小车蝗和黄胫小车蝗作为两个种比较合适;痂蝗亚科和异痂蝗亚科应该合并为一个亚科;飞蝗亚科与斑翅蝗亚科的分类关系尚未解决,需要进一步的研究进行分析验证.     

Phylogenetic relationships of Cheju horses to other horse breeds as determined by mtDNA D-loop sequence polymorphism

Historical records suggest that horses inhabiting the island of Cheju in Korea are descendants of Mongolian horses introduced in 1276. Other studies, however, suggest that horses may have been present on the island prior to the Mongolian introduction. To determine the origin of the Cheju horses we used a phylogenetic analysis of sequences of the mitochondrial DNA (mtDNA) D-loop region, including tRNA Pro and parts of tRNA thr and tRNA Phe sequences (1102-bp excluding the tandem repeat region). Maximum parsimony and neighbor-joining trees were constructed using sequences determined for seven Cheju, four Mongolian, one Przewalskii and two Chinese Yunnan horses, and published sequences for one Swedish and three Thoroughbred horses. Donkey mtDNA was used as an outgroup. We found that the mtDNA D-loop sequence varies considerably within Mongolian, Cheju and Thoroughbred horse breeds, and that Cheju horses clustered with Mongolian horses as well as with horses from other distantly related breeds. On the basis of these findings we propose that horses on Cheju Island are of mixed origin in their maternal lineage, and that horses may have existed and been traded on the island before the Mongolian introduction.