Taxonomic Sense Research Articles

The nature of expression of avian immunity genes during infection with GALLID ALPHAHERPESVIRUS 2 and MELEAGRID ALPHAHERPESVIRUS 1

Marek's disease is a dangerous immunosuppressive viral disease of poultry. Most egg poultry farm in the Russian Federation vaccinate their chickens on the first day of life against this viral disease. Thanks to this vaccine prevention tactic, poultry farms protect themselves from the outbreak of this disease and economic damage. Traditionally, among the viruses related to this disease, there are the 1st serotype of the Marek's disease virus (Gallid alphaherpesvirus 2) and the 3rd serotype of the Marek's disease virus, which is not such in a strict taxonomic sense (Meleagrid alphaherpesvirus 1, also called turkey herpesvirus). When poultry is infected, this virus causes a significant change in the expression of the main immunity genes (IL6, PTGS2, IRF7). Based on the results obtained, it was concluded that the expression of the IL6 and PTGS2 genes was slightly higher than the level of expression of these genes in the control group. It is possible that local immunity was suppressed by the immunosuppressive properties of the Marek's disease virus. When studying the expression of the IRF7 gene, a strong effect of viruses of both serotypes on this gene was found, and Gallid alphaherpesvirus 2 exceeded the level of this effect compared to the effect of Meleagrid alphaherpesvirus 1 by 4 times. These results may indicate that sharply increasing expression of the IRF7 gene may be a sign of Marek's disease virus replication (since Gallid alphaherpesvirus 2 and Meleagrid alphaherpesvirus 1 interact with the same cellular receptor, the vaccine effect of Meleagrid alphaherpesvirus 1 is based on this). On the other hand, we can conclude that the introduction of these viruses does not cause inflammatory and immune reactions in the ileocecal tonsils of birds.

Resurrection of <i>Boiga ranawanei</i> Samarawickrama, Samarawickrama, Wijesena et Orlov, 2005, with Expanded Descriptions and Species Distribution Modelling of Some Indian Taxa of the <i>B. ceylonensis</i> Group (Reptilia: Colubridae)

We resurrect the nominal taxon Boiga ranawanei Samarawickrama, Samarawickrama, Wijesena et Orlov, 2005 as a valid species endemic to Sri Lanka. We uphold the view that B. ranawanei is conspecific with what was previously considered as the Sri Lankan population of ‘B. beddomei’. The revised concept of B. beddomei as a species endemic to the Western Ghats of India and altogether absent from Sri Lanka necessitated the Sri Lankan ‘B. beddomei’ population be conferred with the available nomen B. ranawanei. We also report on further specimens of the two Indian species closely associated with B. ranawanei – B. beddomei that was associated in a nomenclatural sense and B. flaviviridis that is associated in a taxonomic sense. Here, we expand the descriptions of B. beddomei and especially that of B. flaviviridis based on many more additional specimens from several localities across Peninsular India. We again update the key to this group with the inclusion of B. ranawanei. We perform Species Distribution Modelling (SDM) to elaborate on the recorded and simulated distribution range envelopes of the Indian taxa (B. flaviviridis, B. beddomei, B. nuchalis, B. thackerayi) in the B. ceylonesis group. Thus we explain the geographical discontinuity among these taxa to further corroborate our findings on their taxonomic statuses.

New genera and species of Rohrthripidae (Thysanoptera: Tubulifera) from Burmese Cretaceous amber.

The Rohrthripidae is a family of fossil tubuliferan thrips known exclusively from the Cretaceous. Despite typical tubuliferan features, these thrips show terebrantian character states, particularly on the wings and antennae, which have been interpreted as plesiomorphic. At present, the family includes only a single genus, with seven species. In the present study, 11 new species and four new genera of these ancestral thrips are described from Burmese Cenomanian amber: Adstrictubothrips mirapterus gen. et sp. n., Gemineurothrips microcephalus gen. et sp. n., Gemineurothrips peculiaris gen. et sp. n., Paralleloalathrips bivenatus gen. et sp. n., Rohrthrips brachyvenis sp. n., Rohrthrips multihamuli sp. n., Rohrthrips pandemicus sp. n., Rohrthrips rhamphorhynchus sp. n., Rohrthrips setiger sp. n., Sesquithrips markpankowskii gen. et sp. n. and Sesquithrips rostratus gen. et sp. n. Furthermore, Alavathrips moralesi, a species from Spanish Cretaceous amber, is placed into the Rohrthripidae and its sex is reinterpreted as male. The present study, moreover, provides a tighter definition of the Rohrthripidae and a more detailed description of important character states. Finally, it is outlined why it makes taxonomic sense to distinguish Rohrthripidae from the modern Tubulifera, the Phlaeothripidae.

Bot Gummosis of Lemon (Citrus × limon) Caused by Neofusicoccum parvum.

Neofusicoccum parvum, in the family Botryosphaeriaceae, was identified as the causal agent of bot gummosis of lemon (Citrus × limon) trees, in the two major lemon-producing regions in Italy. Gummy cankers on trunk and scaffold branches of mature trees were the most typical disease symptoms. Neofusicoccum parvum was the sole fungus constantly and consistently isolated from the canker bark of symptomatic lemon trees. It was identified on the basis of morphological characters and the phylogenetic analysis of three loci, i.e., the internal transcribed spacer of nuclear ribosomal DNA (ITS) as well as the translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes. The pathogenicity of N. parvum was demonstrated by wound inoculating two lemon cultivars, ‘Femminello 2kr’ and ‘Monachello’, as well as citrange (C. sinensis × Poncirus trifoliata) ‘Carrizo’ rootstock. In artificial inoculations, the fungus was very aggressive on lemons and weakly virulent on citrange, consistently with symptoms observed in the field as a consequence of natural infections. This is the first report of N. parvum, both in a wide and in a strict taxonomic sense, as a pathogen of lemon in Italy.

Diversification of yellow-flowered Sempervivum (crassulaceae) species from the Balkan Peninsula: Evidence from the morphometric study of the epidermal structures of rosette leaves

Several related yellow-flowered houseleek species which occur on the Balkan Peninsula are divided into two complexes: Sempervivum ciliosum (S. ciliosum, S. jakucsii, S. klepa, S. octopodes, and S. galicicum) and the S. ruthenicum complex (S. ruthenicum, S. leucanthum, S. kindingeri, and S. zeleborii). Due to strong phenotypic plasticity and a limited number of studies, it is difficult to assert at this point whether all the above species are well defined in the taxonomic sense. Detailed studies of the epidermal structures have not been conducted for any of the species in either complex. The aim of this study was to investigate the degree of variability of the epidermal structures together with their potential usefulness for the taxonomic characterization of the species studied. A total of 18 quantitative characters of the epidermal structures of the adaxial and abaxial surfaces of the rosette leaves were analysed within 16 populations. In all species, the epidermal cells are polygonal or irregularly shaped, with straight or sinuous anticlinal walls, while the rosette leaves are amphistomatic with anisocytic stomata. Simple biseriate multicellular glandular trichomes were found on the adaxial and abaxial surfaces and the margins of the rosette leaves. The results of the descriptive statistics, univariate (ANOVA) and multivariate statistical analysis (CDA, AHC) showed low to high variability in the epidermal cells, guard cells and trichomes. The multivariate analysis showed diversification among the complexes and species. The length of the marginal and apical trichomes of the rosette leaves contributed most to diversification.

Unlocking plant resources to support food security and promote sustainable agriculture

Societal Impact StatementBiodiversity is essential to food security and nutrition locally and globally. By reviewing the global state of edible plants and highlighting key neglected and underutilized species (NUS), we attempt to unlock plant food resources and explore the role of fungi, which along with the wealth of traditional knowledge about their uses and practices, could help support sustainable agriculture while ensuring better protection of the environment and the continued delivery of its ecosystem services. This work will inform a wide range of user communities, including scientists, conservation and development organizations, policymakers, and the public of the importance of biodiversity beyond mainstream crops.SummaryAs the world's population is increasing, humanity is facing both shortages (hunger) and excesses (obesity) of calorie and nutrient intakes. Biodiversity is fundamental to addressing this double challenge, which involves a far better understanding of the global state of food resources. Current estimates suggest that there are at least 7,039 edible plant species, in a broad taxonomic sense, which includes 7,014 vascular plants. This is in striking contrast to the small handful of food crops that provide the majority of humanity's calorie and nutrient intake. Most of these 7,039 edible species have additional uses, the most common being medicines (70%), materials (59%), and environmental uses (40%). Species of major food crops display centers of diversity, as previously proposed, while the rest of edible plants follow latitudinal distribution patterns similarly to the total plant diversity, with higher species richness at lower latitudes. The International Union for Conservation of Nature Red List includes global conservation assessments for at least 30% of edible plants, with ca. 86% of them conserved ex situ. However, at least 11% of those species recorded are threatened. We highlight multipurpose NUS of plants from different regions of the world, which could be key for a more resilient, sustainable, biodiverse, and community participation‐driven new “green revolution.” Furthermore, we explore how fungi could diversify and increase the nutritional value of our diets. NUS, along with the wealth of traditional knowledge about their uses and practices, offer a largely untapped resource to support food security and sustainable agriculture. However, for these natural resources to be unlocked, enhanced collaboration among stakeholders is vital.

Use cases for Taxonomic Name Services

Catalogue of Life Plus (CoL+) was started in 2017 as a collaborative project between the Catalogue of Life (COL), the Global Biodiversity Information Facility (GBIF), Naturalis Biodiversity Center, Barcode of Life Database (BOLD), Biodiversity Heritage Library (BHL), Encyclopedia of Life (EOL), Integrated Taxonomic Information System (ITIS) and representatives from natural history museum collections. The participants jointly recognized a need for the wider biodiversity community to coalesce around common and coordinated approaches for mobilizing and inter-linking biodiversity data and information across a range of scales, themes and types. The Catalogue of Life was identified as being the clear choice to deliver taxonomic services to support these partners. Taxonomic services refer to solutions that address challenges inherent to scientific names: the ubiquitous, and often sole, contextual linkage between a biodiversity data object and the taxon to which it is linked. Without access to expert-mediated taxonomic knowledge, biodiversity data networks risk integrating or delivering biodiversity data that is incomplete or may not make taxonomic sense. As a globally comprehensive and expert-mediated taxonomic resource, the Catalogue of Life is well-positioned to provide the underlying data and services to address these challenges and support a broad community of stakeholders. With financial support from the Netherlands Biodiversity Information Facility, the Netherlands Ministry of Education, Science, and Culture as well as technical support from GBIF, CoL+ represents an effort to stabilize the Catalogue of Life checklist products and refine a roadmap for future services -services that must be informed by the needs of users. The COL+ initiative provides an opportunity to document and understand the requirements of both Col current users and a wider future user base. Key to any expansion is ensuring a clear understanding and the appropriate response to user needs. This includes not only the requirements of "taxonomic data consumer" stakeholders, such as those listed above, but also the needs and motivations of the expert taxonomic community behind the current and future Catalogue of Life. This session will focus on reviewing the user requirements of a diverse community of both taxonomic data producers and consumers and organizing these stories into a set of categories from which we will identify clear and useful tools and services. These will establish the basis for a compelling roadmap for the Catalogue of Life as an enabling foundation to an interlinked and global biodiversity data infrastructure.

Seasonal Distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1 Species and Impact on Incidence of Begomoviral Diseases in Baja California Sur.

For more than four decades, the presence of the whitefly Bemisia tabaci Gennadius complex as a pest and transmitter of begomoviral diseases has been one of the most important phytopathological events in cultivated species worldwide. In addition, the number of whitefly species, as well as the viruses they transmit, has been increasing over time. In the state of Baja California Sur (BCS), Mexico, the diversity of B. tabaci has been delimited to MEAM1 and NW species, affecting mainly tomato, pepper, and squash. However, the relationship of these species with the dispersion of the begomoviruses previously detected in the study area is still unknown. In a 5-yr study (2012-2016), these species of whiteflies and begomoviruses were identified. Moreover, the recurrence, seasonal distribution, and impact they have on the spread of the begomoviral diseases were assessed. The identification of whiteflies was done targeting the mtCOI by PCR-DNA barcoding assay. For begomoviruses identification, a set of degenerate and specific primers targeting the IR region and CP gene were used. To determine seasonal abundance, monitoring was performed every 15 d by means of yellow traps. The MEAM1 species in all localities was observed with the highest peak population (>10 whiteflies/trap) from March to April. The guidelines for naming begomovirus species for the International Committee on Taxonomy of Viruses (ICTV) establish that the names when they are preceded by the acronym the whole name is in lowercase, not italicized (e.g. bean golden mosaic virus (BGMV)); when the name goes alone without the acronym then its capitalizes the first letter (e.g. Bean golden mosaic virus) and when these are referred to in a taxonomic sense they are italicized and the first letter is capitalized (e.g. Bean golden mosaic virus). This study provides details of the distribution and occurrence of MEAM1 species and diversity of begomoviruses that could be useful in disease management in BCS and worldwide.

New mitogenome and nuclear evidence on the phylogeny and taxonomy of the highly zoonotic tapeworm Echinococcus granulosus sensu stricto

Cystic echinococcosis, a zoonotic disease caused by Echinococcus granulosus sensu lato (s. l.), is a significant global public health concern. Echinococcus granulosus s. l. is currently divided into numerous genotypes (G1–G8 and G10) of which G1–G3 are the most frequently implicated genotypes in human infections. Although it has been suggested that G1–G3 could be regarded as a distinct species E. granulosus sensu stricto (s. s.), the evidence to support this is inconclusive. Most importantly, data from nuclear DNA that provide means to investigate the exchange of genetic material between G1–G3 is lacking as none of the published nuclear DNA studies have explicitly included G2 or G3. Moreover, the commonly used relatively short mtDNA sequences, including the complete cox1 gene, have not allowed unequivocal differentiation of genotypes G1–G3. Therefore, significantly longer mtDNA sequences are required to distinguish these genotypes with confidence. The main aim of this study was to evaluate the phylogenetic relations and taxonomy of genotypes G1–G3 using sequences of nearly complete mitogenomes (11,443bp) and three nuclear loci (2984bp). A total of 23 G1–G3 samples were analysed, originating from 5 intermediate host species in 10 countries. The mtDNA data demonstrate that genotypes G1 and G3 are distinct mitochondrial genotypes (separated by 37 mutations), whereas G2 is not a separate genotype or even a monophyletic cluster, but belongs to G3. Nuclear data revealed no genetic separation of G1 and G3, suggesting that these genotypes form a single species due to ongoing gene flow. We conclude that: (a) in the taxonomic sense, genotypes G1 and G3 can be treated as a single species E. granulosus s. s.; (b) genotypes G1 and G3 should be regarded as distinct genotypes only in the context of mitochondrial data; (c) we recommend excluding G2 from the genotype list.

Getting specific: making taxonomic and ecological sense of large sequencing data sets.

Eukaryotic microbes comprise a diverse collection of phototrophic and heterotrophic creatures known to play fundamental roles in ecological processes. Some can be identified by light microscopy, generally the largest and with conspicuous shapes, while the smallest can be counted by epifluorescence microscopy or flow cytometry but remain largely unidentified. Microbial diversity studies greatly advanced with the analysis of phylogenetic markers sequenced from natural assemblages. Molecular surveys began in 1990 targeting marine bacterioplankton (Giovannoni et al. ) and first approached microbial eukaryotes in three studies published in 2001 (Díez et al. ; López-García et al. ; Moon-van der Staay et al. ). These seminal studies, based on cloning and Sanger sequencing the complete 18S rDNA, were critical for obtaining broad pictures of microbial diversity in contrasted habitats and for describing novel lineages by robust phylogenies, but were limited by the number of sequences obtained. So, inventories of species richness in a given sample and community comparisons through environmental gradients were very incomplete. These limitations have been overcome with the advent of high-throughput sequencing (HTS) methods, initially 454-pyrosequencing, today Illumina and soon others to come. In this issue of Molecular Ecology, Egge et al. () show a nice example of the use of HTS to study the biodiversity and seasonal succession of a particularly important group of marine microbial eukaryotes, the haptophytes. Temporal changes were analysed first at the community level, then at the clade level, and finally at the lowest rank comparable to species. Interesting and useful ecological insights were obtained at each taxonomic scale. Haptophyte diversity differed along seasons in a systematic manner, with some species showing seasonal preferences and others being always present. Many of these species had no correspondence with known species, pointing out the high level of novelty in microbial assemblages, only accessible by molecular tools. Moreover, the number of species detected was limited, agreeing with a putative scenario of constrained evolutionary diversification in free-living small eukaryotes. This study illustrates the potential of HTS to address ecological relevant questions in an accessible way by processing large data sets that, nonetheless, need to be treated with a fair understanding of their limitations.

A taxonomic survey of the genus Vitis L. (Vitaceae) in Italy, with special reference to Elba Island (Tuscan Archipelago)

As resulted from recent floristic investigations conducted in southern and central Europe, the genus Vitis proved to be, in these areas, an intricate critical group, whose interpretation, often influenced by ampelographic approaches, needed to be clarified in a strict taxonomic sense. The current paper analyzes the taxonomy and the distribution of seven taxa recorded in Italy and assigns new names to three nothospecies, naturalized and/or invasive in additional European countries: V. ×instabilis (= V. riparia × V. rupestris), V. ×koberi (= V. berlandieri × V. riparia), V. ×ruggerii (= V. berlandieri × V. rupestris). Nomenclatural and systematic aspects regarding V. vinifera are also discussed. Original and detailed descriptions, identification keys, illustrations and information on distribution and ecology are provided.

Visions of Technology, Gender, and Knowledge Production

Visions of Technology, Gender, and Knowledge Production Joy V. Fuqua (bio) Katie King’s Networked Reenactments: Stories Transdisciplinary Knowledges Tell, foreword by Donna Haraway, Durham: Duke University Press, 2011 Knut Holtan Sørensen, Wendy Faulkner, and Els Rommes’s Technologies of Inclusion: Gender in the Information Society, Trondheim, Norway: Akademika Publishing, 2011 It is often the case that I read a book that inspires me to rethink a particular phenomenon. However, it is rare that a book challenges me to think differently about what it means to think. Katie King’s Networked Reenactments accomplishes both things. It is, in significant ways, a very tough act to follow. Technologies of Inclusion, collaboratively researched and written by Knut Holtan Sørensen, Wendy Faulkner, and Els Rommes, presents an overview of recent work on women and information and computer technologies (ICT) conducted in Europe. This volume contributes to an already existing field of knowledge and challenges the dominance of the “exclusion” paradigm in relation to women and ICT. It is a synthesizing text that represents a summary of research regarding some of the key, structuring assumptions about women and ICT. That, in addition to its focus on European contexts, is its strength. These two books, Networked Reenactments and Technologies of Inclusion, represent markedly different ways of (1) conceptualizing knowledge production and (2) engaging with gender and “the digital.” The two books share a concern for gender and digital technologies. Yet this is where they part company in terms of conceptualization, methodology, and findings. As a queer feminist media studies scholar, I found that Networked Reenactments consistently challenged my own assumptions about disciplinarity, the idea of discrete objects of study, and temporal categorization. As a queer feminist media studies scholar, I found that Technologies of Inclusion tended to reconfirm what I already thought I knew about women and ICT. King’s book gathers an impressive array of disparate objects, yet in doing so, the text tends to avoid what might be understood as a straight-forward [End Page 280] textual analysis of these various objects. Yes, King’s book is about reenactment as a transdisciplinary phenomenon, but for readers who have a strict, taxonomic sense of what reenactment means, they may be disappointed. From her approach to the multiple texts of Highlander, Xena: Warrior Princess, and the digital fandom that has grown around these programs, King rarely settles on one thing. This can be felt as frustration or as a dizzying, even exhilarating, movement through varying intensities of engagement across, rather than within, transmedia. King’s prose, at times poetic and at other times anecdotally provocative, is the reader’s guide. It’s an invitation to go on a journey in which the destination is not known in advance. That, for this reader, was a welcome change in relation to knowledge production in which so much contemporary scholarship tends to lead the reader on a cozy trek down anticipated paths. Using the key concepts of transmedia, posthumanities, and pastpresents, King is interested in the ways that reenactment, as a nongeneric mode, may be a hybrid frame for displacing interpretive, textual exercises. In the book’s conclusion, King offers the following explanation for her approach to this form of knowledge production: “It makes for an odd sort of book, this reenactment R and D. At one level it is a demonstration of how one sort of case study within a feminist transdisciplinary posthumanities might work. Reenactments are sometimes then an object for illustration, but never only that” (273). This book is a queer one, it is an odd one, in that it refuses to engage in scholarship that is predictable or reassuringly recognizable. To be sure, one of the things we learn most about in this book is King as a curious reader, as an odd reader who expresses queer affection for multiple “care abouts.” The main “care about” of Technologies of Inclusion: Gender in the Information Society is women’s relationship to computer technologies. The book’s collective contribution is the result of a series of research projects that examined the ways that women use and engage with computer and information technologies in the early years of the twenty-first century. If one of...

EmilianiaSánchez, 1999 is not a homonym ofEmilianiaHay and Mohler, 1967

In the July issue of Journal of Paleontology, 84(4), Sánchez (2010) proposed the new genus nameEmiliodontafor the Ordovician bivalve genusEmilianiaSánchez, 1999 because of assumed homonymy withEmilianiaHay and Mohler, 1967 (in Hay et al., 1967). The supposed senior name, the genusEmilianiaHay and Mohler, belongs to the coccolithophores, a group of unicellular eukaryotic algae, which have traditionally been treated as plants (e.g., Glaessner, 1945; Tappan, 1980; see also Green and Jordan, 1994; Andersen, 2004 for modern classification) and to which the International Code of Botanical Nomenclature (ICBN) applies. In the original description ofEmilianiaHay and Molher the ICBN was used (Hay et al., 1967, p. 447) and the name was validly published under its rules. Animals such as the bivalveEmilianiaSánchez, 1999, in contrast, are treated under the International Code for Zoological Nomenclature (ICZN). Both codes are independent (ICBN, Principle I: Greuter et al., 1993, 2000; McNeill et al., 2006; ICZN Article 1: Ride et al., 1985, 1999), and therefore the same names (“homonyms” sensu lato) can coexist under different codes. Consequently,EmilianiaSánchez andEmilianiaHay and Molher are not homonyms in a taxonomic sense but are both legitimate names under the respective code. Furthermore, the nameEmiliodontaSánchez 2010 is superfluous and illegitimate, as “[…] the name of an animal taxon is not to be rejected merely because it is identical with the name of a taxon that is not animal.” (ICZN Article 1.4: Ride et al., 1999).

Strain, clone and species: comments on three basic concepts of bacteriology

Different aspects of the terms strain, clone and species are discussed. The term strain is commonly used to denote a pure culture - here called 'the strain in the taxonomic sense' - but does also refer to a natural concept closely related to the clone. The term clone on the other hand is used both in a general and in a more restricted sense, the latter indicating a low degree of genetic exchange. The important distinction between the definition of a species and the criteria for a species is emphasised and the main kinds of criteria are considered.

Multivariate Discrimination of Colorado PlateauGilaspp.: The “Art of Seeing Well” Revisited

Fishery managers have long been troubled by phenotypic variation within and among Colorado Plateau Gila. The problem is twofold. From an historical perspective, there was reticence to investigate fishes long considered as “undesirable.” In a taxonomic sense, there is confusion over within- and among-species variability. We document the former, then clarify the latter by applying discriminant analysis to meristic and morphometric data collected from museum specimens. We test three hypotheses: roundtail chub G. robusta humpback chub G. cypha and bonytail G. elegans are morphologically indistinguishable; juveniles are assignable to species based upon adult characters; and putative hybrids are morphologically intermediate between parental forms. Through the use of meristic characters in a nonparametric discriminant analysis, over 95% of all adults were segregated to species. By using morphometric characters, 97% could be allocated to species. Gila robusta was easily separated from G. cypha and G. elegans. The latter were most difficult of all species-pairs to discriminate, yet field characters still segregated them at better than 95%. A discriminant function, based upon five morphometric characters, will allocate unknowns to species. Juvenile G. robusta were easily discriminated (>97%), but juveniles of G. cypha and G. elegans were often misidentified as G. robusta. Putative hybrids were generally assigned to one or the other parental form; thus, hybrid intermediacy could not be rejected. However, paucity of hybrids weakened the test. We conclude that factors most important in segregating these species are character selection, adequate analyses, and “the art of seeing well.”

How Did Bacteria Come to Be?

Bacteria in the modern taxonomic sense are one of the three Domains. They must have split from the other two after the bulk of the development of biochemistry and cell biology had taken place. Up to the time of the Last Universal Ancestor (LUA) the world had been monophyletic with little stable diversity. This is to say that as advances took place the older forms were eliminated and diversity was only temporary. Two kinds of events could, in principle, permit stable diversity to arise. One kind occurs when two nearly simultaneous, different advances occur, both of which overcome the same problem. While the previous type would be supplanted, if the new types did not compete with each other, new niches and habitats could lead to stable diversity. The second kind is a saltation or macroevolutionary event that greatly expands the biota and reduces previous constraints and thereby drastically reduces competition; this generally leads to a 'species radiation' and results in the development of a spectrum of biological types some of which persist and do not compete with each other. It is proposed that the two splits to yield the three Domains of Bacteria, Archaea, and Eukarya, resulted from one of each of these two processes leading to diversity. One arose from the consequences of cells accumulating substances from the environment, thus increasing their internal osmotic pressure. This resulted in two nearly simultaneous biological solutions: one (Bacteria) was the development of the external sacculus, i.e. the formation of a stress-bearing exoskeleton. The other (Eukarya) was the development of cytoskeletons and mechanoenzymes, i.e. formation of an endoskeleton. The other event causing diversity was the invention of an effective way to tap a new energy source and allow the biomass to increase extensively permitting a radiation of many different types of organisms. I suggest that this seminal advance was the development of methanogenesis. This caused a short-lived expansion and radiation before oxygen-producing photosynthesis allowed a still more major expansion and decreased the number of methanogens. Some details of these processes are elaborated. In particular, the evolutionary process that permitted the development of a sacculus, interpreted in light of the bacterial physiology of today's organisms is presented. It is argued that many great advances arise by developing a number of totally different processes for other purposes that can then each be modified to combine for yet another purpose.

Notes on Marsdenieae (Asclepiadaceae): A New, Unusual Species of Hoya from Northern Borneo

Notes on Marsdenieae (Asclepiadaceae): A New, Unusual Species of Hoya from Northern Borneo

Dental development in South African australopithecines. Part I: Problems of pattern and chronology

AbstractIt is well known that humans take about twice as long as apes to mature. The traditional view that such delayed maturation was already present in australopithecines has been called into question during the past several years. We have approached this problem by looking at patterns of dental development in gracile and robust australopithecines from South Africa and comparing them to patterns found in extant humans and apes. We have employed both 2 and 3 dimensional computed tomography in our research. The dental growth patterns in these two australopithecine morphs differ, particularly in M1/I1 development. The robust australopithecines are more humanlike and the gracile australopithecines more apelike in this feature (“humanlike” and “apelike” are not used in any taxonomic sense). Pattern and chronology of dental development must be considered separately. Several major problem areas for future research are identified, most of which revolve around the issue of intra‐ versus interspecific variation.

Fossil Mastixioid (Cornaceae) Alive in Eastern Asia

The tree species Diplopanax stachyanthus, wrongly placed in the Araliaceae, belongs in fact to the mastixioid subfamily of Comaceae. Fruit features make it congeneric with Mastixicarpum, part of a woody-fruited complex known heretofore from Tertiary fossils. WHEN A GROUP of organisms known just from fossils turns out to have survivors, the finding attracts wide attention. Among animals the famed example is a fish, the coelacanth. Among higher plants the one example has been Metasequoia, found alive in the 1940s. We report the discovery of a living woody-fruited mastixioid, member of a plant group thought to have expired some 4 million years ago. No fossils are more prominent in lignite beds of Europe than mastixioid fruits. Collectors of the 19th century called them palm fruits, acorns, orAnnona seeds. By the early 1930s, however, British paleobotanists had trained their lenses on internal structure and had made correct comparison with fruits of Mastixia, a genus of trees now confined to Southeast Asia and islands of the western Pacific. The 19 living species of Mastixia have fruits that are much alike, but related fruits from fossil beds are diverse-so diverse that fossil species have been added to Mastixia and fossil genera established near Mastixia, to make taxonomic sense of the diversity. Species of Mastixia, extant and extinct, with species of related fossil genera, comprise subfamily Mastixioideae of the dogwood family, Cornaceae. Following the British lead, German paleobotanist Franz Kirchheimer searched the rich fossil fruit collections of the European mainland with mastixioids in mind and found kinds not represented in the British record (Kirch1 Received for publication 5 December 1989; revision accepted 25 January 1990. Research began while Xiang was a visiting fellow at the National Museum of Natural History. A. L. Takhtajan, leaming of our work, graciously gave up his research on Diplopanax and sent us his slides. We thank M. Leighton for information, D. Dean and S. Yankowski for technical help, and V. Krantz for photographs. 2 Current address: Department of Botany, Washington State University, Pullman, WA 99164. heimer, 1957, for review). Fifteen genera of mastixioid fruit remains came into print eventually, but current taxonomic views reduce the worldwide list to eight fossil genera, 33 fossil species. Mastixioids are relatively few in North America, and the record ends in the early Tertiary. The European record, however, reaches from uppermost Cretaceous to late Miocene, roughly from 65 million to 7 million years ago. Some of these fruits are superbly preserved, and in some places they abound; Poland's Turow mine alone has yielded 2,400 fruits in five mastixioid genera. Though Mastixia-like leaves and pollen grains occur as fossils, they lack the diversity that makes mastixioid fruits important for inferring past climatic changes. Mastixioid flora is the European term for the subtropical to paratropical broad-leaved evergreen vegetation that once covered much of the northern hemisphere. Mastixioid fruits are stone fruits; as the fruit grows, its inner cell layers turn into a woody housing for a chamber that contains a single seed. Some ofthe ancient mastixioids had multiple seed chambers in their stones, and the various kinds differed with regard to the hardness of the fruit's outer layers. Fossils indicate that the Mastixioideae evolved in two main lines: a single-genus line (Mastixia itself) having fruits with soft outer cell layers, and a several-genus line having fruits with hard outer layers. For convenience we call the latter group woody-fruited, even though the outer tissue was more leathery than woody in some species. Tooth marks and gnawed holes in fossil and modern stones show that mastixioid fruits can be moved about, and often destroyed, by rodents. The fleshy outer layers of Mastixia's fruits give it the advantage of nondestructive bird dispersal, and that may be the reason for Mastixia's survival into modern times. It was long supposed that Mastixia's woody-

Comment on Offner

OFFNER'S PAPER PRESENTS a strange combination of theoretical ignorance, faulty scholarship, distortions, and snide remarks (refer to American Antiquity 46:43-61). I agreed to write this reply only because the editor wrote me that the paper had already been accepted for publication, and I assume, from the usual content of this journal, that its readers may not be especially familiar with analyses of economic systems on the basis of historical documentation. I will not bother to comment on Offner's disparaging remarks about scholars who have discussed ancient Mexico with reference to Marxian theory, specifically Kirchhoff and Monz6n. Anyone acquainted with the history of ethnohistorical research on Mesoamerica will be aware of the significance of the contribution of Paul Kirchhoff and of the influence he has had on Mesoamerican studies. In his paper, Offner objects to the use of the Marxian concept of the Asiatic mode of production; he denies the importance of irrigation; and he concentrates his attacks upon my work, particularly in regard to the issues of private property in land, the importance of the market, and government control of the economy. He also raises questions of method. I see no point in dealing with his handling of the Asiatic mode of production or of Wittfogel's theory of Oriental Society. Offner seems to have obtained his ideas primarily from secondhand summaries; he does not take into account the various was ways in which Marx's formulation has been developed in recent years, although I refer to this in one of the articles he criticizes (Carrasco 1978:66 ff.), and he obviously does not understand that in Wittfogel's theory there are types of Oriental society with little or no irrigation, with private property in land, and with widespread market activities, the major points presented by Offner as arguments against the applicability of the model to ancient Mexico. Further, he does not realize that basically I use this model as a heuristic device. My analysis stands whether we label the ancient Mexican economy as Asiatic mode of production or not, and in my conclusion I raise questions about the use of the model in a taxonomic sense. Offner's ignorance of the general concepts I derive from Polanyi is equally obvious in his references to redistribution and in his failure to understand the difference between price-making markets and set-price markets. Since Offner questions my views, whether they refer to Tetzcoco or to other areas, I will not go at length into the differences between Tetzcoco and other political units of ancient central Mexico. It is well known that there were significant differences between the various Nahuatl groups of the Central Highlands, but it would take too much space to discuss this problem adequately, and in any case some of those differences are not related to the issues raised by Offner. Basically I will restrict my comments to his attacks on my published work. I have never denied the importance of irrigation in ancient Mexico. As I have stated clearly elsewhere, basically I agree with the work of Palerm and his associates (Palerm 1972, 1973;