Cladistic analyses of behavioural variation in wild Pan troglodytes: exploring the chimpanzee culture hypothesis

Long-term field studies have revealed considerable behavioural differences among groups of wild Pan troglodytes. Here, we report three sets of cladistic analyses that were designed to shed light on issues relating to this interpopulation variation that are of particular relevance to palaeoanthropology.In the first set of analyses, we focused on the proximate cause of the variation. Some researchers have argued that it is cultural, while others have suggested that it is the result of genetic differences. Because the eastern and western subspecies of P. troglodytes are well differentiated genetically while groups within the subspecies are not, we reasoned that if the genetic hypothesis is correct, the phylogenetic signal should be stronger when data from the eastern and western subspecies are analysed together compared to when data from only the eastern subspecies are analysed. Using randomisation procedures, we found that the phylogenetic signal was substantially stronger with in a single subspecies rather than with two. The results of the first sets of analyses, therefore, were inconsistent with the predictions of the genetic hypothesis.The other two sets of analyses built on the results of the first and assumed that the intergroup behavioural variation is cultural in nature. Recent work has shown that, contrary to what anthropologists and archaeologists have long believed, vertical intergroup transmission is often more important than horizontal intergroup transmission in human cultural evolution. In the second set of analyses, we sought to determine how important vertical transmission has been in the evolution of chimpanzee cultural diversity. The first analysis we carried out indicated that the intergroup similarities and differences in behaviour are consistent with the divergence of the western and eastern subspecies, which is what would be expected if vertical intergroup transmission has been the dominant process. In the second analysis, we found that the chimpanzee cultural data are not only comparable to a series of modern human cultural data sets in terms of how tree-like they are, but are also comparable to a series of genetic, anatomical, and behavioural data sets that can be assumed to have been produced by a branching process. Again, this is what would be expected if vertical inter-group transmission has been the dominant process in chimpanzee cultural evolution.Human culture has long been considered to be adaptive, but recent studies have suggested that this needs to be demonstrated rather than assumed. With this in mind, in the third set of analyses we investigated whether chimpanzee culture is adaptive. We found the hypothesis that chimpanzee culture is adaptive was supported by an analysis of data from the Eastern African subspecies, but not by an analysis of data from the eastern and western subspecies.The results of our analyses have implications for the number of subspecies in Pan troglodytes, the relationship between hominin taxa and Palaeolithic industries, and the evolution of hominin cognition and behaviour.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

柳属的分支系统学分析

基于61个广义的形态学性状,以杨属为外类群对柳属进行了分支系统学分析.经简约性分析,得到了21个同等简约的分支树,其严格一致树支持柳属为一个自然的分类群,但不支持将钻天柳属和心叶柳属从柳属中划分出去独立成属,也不支持对柳属进行属级水平上的细分,后两个结果得到孢粉学和分子系统学研究的支持.柳亚属为一个单系分支,皱纹柳亚属和黄花柳亚属也形成了一个单系分支.根据本研究的结果,建议将柳属划分为钻天柳亚属、柳亚属及黄花柳亚属3个亚属.由于较低的靴带支持率,其系统发育关系难于探讨.鉴于分支分析的一致性指数、保持性指数、各分支内部的支持率均不高,柳属的属下分类系统的划分有待进一步的研究.     

基于广义形态学性状对木通科的分支系统学分析

基于43个广义的形态学性状,对木通科进行了分支系统学分析。经过简约性分析,得到了68个同等简约的分支树。50％多数规则一致树的分支结构与以前建立的族划分系统基本一致。外类群大血藤属与木通科的勃奎拉藤属形成姐妹群,与以前的分支分析结果一致,但在分子系统发育树中,大血藤属却是整个木通科的姐妹群;除此之外,形态分支树的结构与分子树的结构差别不大,但一致性指数、保持性指数和各分支内部支持率均较低。单型的猫儿屎族和串果藤族位于分支树的基部,拉氏藤族与木通族是姐妹群,在木通族内,长萼木通属和木通属是姐妹群,作为一个分支;另一分支是PHS（牛藤果属、八月瓜属和野木瓜属）复合群,牛藤果属位于八月瓜属和野木瓜属各类群的基部。但八月瓜属和野木瓜属的属内系统发育关系仍有待进一步研究。     

DNA sequence analyses of the ribosomal spacer regions in theTriticeae

Two regions of the ribosomal DNA (rDNA) were sequenced from a range of species from the tribeTriticeae. One region, the central spacer, was found to be more divergent in sequence than the other, the 18 S-spacer junction. Both regions contained sequences 20–30 bp long which were more highly conserved than the remainder of the region and their possible significance in rDNA expression is discussed. Phenetic relationships based on the sequence data were generally consistent with the relationships based on other criteria. Species possessing the S, E, J₁J₂, D, and B genomes clustered together, with the H genome species being the most distinct of those examined. The R, P, and V genome species occupy an intermediate position in the overall pattern of relationships. Some relationships differed in detail from those established by other parameters, for example the position of the N genome species, and explanations for discrepancies of this type are discussed.     

Cladistic analysis of some freshwater araphid diatoms (Bacillariophyta) with particular reference toDiatoma andMeridion

Interrelationships of the ribbed araphid diatoms have been reinvestigated using a cladistic analysis of a revised morphological dataset. The presence of silicified transapical ribs has previously been used to distinguish between different groups and its ability to serve as a distinguishing feature is reevaluated. The importance of valve symmetry, not fully appreciated in a previous paper, is examined. The evolution of heteropolarity, and its importance in taxonomy appear more complex than is implied by a simple dichotomy dividing groups of species into heteropolar and isopolar forms, involving an inferred evolutionary transformation from one condition to the other. This analysis proposes a close relationship betweenDiatoma, Fragilariforma, Asterionella, Distrionella, Meridion, Tabellaria, andTetracyclus. It also confirms the sub-division ofDiatoma into two closely related taxa. The genusMeridion, however, should not include both heteropolar and isopolar species in a single genus. Although the species are closely related, the isopolar species are more closely related toTabellaria andTetracyclus than they are to the heteropolar species ofMeridion.     

Multivariate and cladistic analyses of the purple-flowered species ofErysimum (Cruciferae) from the Iberian Peninsula

A taxonomically difficult purple-flowered group within the genusErysimum, restricted to the Iberian Peninsula, is analyzed by multivariate and cladistic analyses. 51 specimens have been scored for 14 characters. Both principal components and discriminant analyses provide support to the recognition of the five species considered by the author, namelyE. linifolium, E. lagascae, E. baeticum, E. popovii, andE. cazorlense. Cladistic analysis, using 7 characters resulted in a single most parsimonious cladogram containing no homoplasies. The pattern of morphologic divergence follows a clear NW.-SE. trend, which is congruent with the topology of the cladogram. This trend significantly affects growth-form as well as fruit characters, both providing the main grounds for species recognition. The different behavior and significance of several characters in both kinds of analysis is discussed. The co-occurrence of morphologically similar individuals differing in the flower color is discussed, too. Possible explanations for this phenomenon involve hybridization in a wide sense or, alternatively, rejecting the assumption of monophyly for the group.     

Glucosinolate spectrum of some AlgerianCruciferae

Seventeen glucosinolates were identified and quantified by micro-scale GC analysis in Algerian samples fromSisymbrieae, Arabideae, Lepidieae, andBrassiceae tribes of theCruciferae. Major glucosinolates and their amino acid precursors allowed species to fall naturally into tribes as classified byJanchen.     

A cladistic analysis of the tribeAstereae (Asteraceae) with notes on their evolution and subtribal classification

TheAstereae were surveyed and the genera arranged in 23 informal groups. The generic groups were used to sample representative genera for a cladistic analysis based on morphological characters. The resulting cladogram was used for discussion of evolution and subtribal classification within the tribe. The lower basic chromosome numbers x = 4, 5, 6, and 8 are interpreted as reductions from a primitive x = 9. The subtribeGrangeinae occupies a phylogenetically basal position as sister group to the rest of the tribe. This may be divided into two large groups, largely corresponding to the homochromousSolidagininae and to the heterochromousAsterinae sensu lato, i.e. including theBellidinae, Hinterhuberinae, Conyzinae, andBaccharidinae. The latter four subtribes are derived within theAsterinae, and hence reduced to synonymy. Several intercontinental relationships indicate that a geographical subdivision of the tribe should be avoided, although in our analysis most of the groups proved to be restricted to one of five major regions.     

Giemsa C-banded karyotypes of some diploidArtemisia species

Detailed C-banded karyotypes of eight diploidArtemisia species from three different sections are reported together with preliminary observations on three additional related diploid species. In the majority, the overall amount of banding is relatively low. Bands are mostly confined to distal chromosome regions; intercalary banding is virtually absent and centromeric heterochromatin is also scarce. With the exception ofA. judaica there is in general great uniformity in karyotype structure but considerable interspecific variation in total karyotype length (and hence DNA content) ranging from 44 µm inA. capillaris (2n = 18) to 99 µm inA. atrata (2n = 18).A. judaica (2n = 16; total karyotype length 97 µm) was distinguished by its karyomorphology, with one large non-banded metacentric chromosome pair and 7 pairs of smaller terminally banded meta- or submetacentric chromosomes.     

A cladistic study of North AmericanCoreopsis (Asteraceae: Heliantheae)

A cladistic study of all 44 species of North AmericanCoreopsis was performed using 35 characters. The resulting cladogram indicated that all 11 sections are monophyletic. At the intersectional level, two lineages were revealed, one consisting of six sections occurring almost exclusively in Mexico and California, and another comprising five sections restricted largely to the eastern and southeastern United States. The cladogram is similar to phylogenies produced by less explicit methods but it differs in two major respects: the monotypic sect.Silphidium is placed with other sections from the southeastern United States rather than with Mexican sections, and sect.Anathysana from Mexico is more closely allied with the three California sections than with sect.Electra from Mexico.     

The karyology of some neotropicalStyracaceae

Chromosome numbers and karyomorphological characters have been investigated inPamphilia andStyrax (Styracaceae). Counted for the first time in the genus, two species ofPamphilia were found to have 2n = 16. The twoStyrax spp. investigated share withPamphilia the same chromosome number, a peculiar condensation behaviour of the chromosomes (Fig. 1a–c) and the same type of semi-reticulate interphase nucleus, results which indicate a close relationship of the two genera. The base number inStyracaceae is probably x = 8 (2n = 2x = 16) with stabilized triploids inHalesia andPterostyrax (2n = 3x = 24). A preliminary comparison withSapotaceae andEbenaceae does not allow a general karyological characterisation of the orderEbenales.     

Phylogenetic analyses and chromosome evolution in Convallarieae (Ruscaceae sensu lato), with some taxonomic treatments

The tribe Convallarieae, comprising 10 genera and 95 species, has recently been transferred from its own family to Ruscaceae sensu lato. In this study, sequence data from trnK and rbcL were analyzed for 19 species in 8 genera, and chromosome morphology was analyzed for 17 species in 7 genera. The parsimony analysis of trnK and rbcL sequences showed that Convallarieae are monophyletic. Although early branches did not receive strong bootstrap support, Convallaria diverged at the first branch, followed by Speirantha. The rest of the tribe was split into three, well-supported clades: one with Reineckea, the second with Campylandra and Rohdea, and the third with Tupistra, Tricalistra, and Aspidistra. Two monotypic genera, Rohdea and Tricalistra, were embedded in a clade of Campylandra and of Tupistra, respectively. Three karyotypes were distinguished in the tribe on the basis of the basic number and morphology of metaphase chromosomes: Convallaria type (with x=19 and unimodal chromosome length), Tupistra type (with x=19 and trimodal chromosome length), and Aspidistra-elatior type (with x=18 and trimodal chromosome length). The character-state distribution in the molecular tree showed that the Convallaria type is plesiomorphic, from which was derived the Tupistra type and subsequently the Aspidistra-elatior type. Taxonomic treatments to transfer Campylandra to Rohdea and Tricalistra to Tupistra are also given.     

The occurrence of vascular tracheids inBetula and some otherBetulaceae genera

The occurrence of vascular tracheids inBetula, Alnus, Carpinus andCorylus is reported. It is established that the cells are a consistent feature in early and late wood where they are associated with vessel elements in radial multiples. The possible function and taxonomic importance of these cells are briefly considered.     

On some species ofMycogloea

Three new species ofMycogloea are described and illustrated; they are:M. amethystina from Canada,M. nipponica, from Japan, andM. bullata from Thailand.Mycogloea tahitiensis is reported from Japan and additional undescribed taxa in the genus are briefly noted. Some characteristics of the genus are discussed, and a key is provided for six species recognized at this time.     

Fragrance analyses,an aid to taxonomic relationships of the genusCoryanthes (Orchidaceae)

All members of the investigated genusCoryanthes (subtribeStanhopeinae) are pollinated by male euglossine bees. The different fragrance profiles are the primary reproductive isolating mechanisms, because the flowers are interfertile. The fragrance patterns of 17 species ofCoryanthes were analyzed by gas chromatography as a means to improve the classification of this genus. A first amine (2-N-methylaminobenzaldehyde) was found to be the main fragrance compound of an as yet unclassifiedCoryanthes species.