SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Alpha taxonomy

158

Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970-2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization.

Concepts: Time, Human migration, Taxonomic rank, Centuries, Alpha taxonomy

110

The capability of animals to emit light, called bioluminescence, is considered to be a major factor in ecological interactions. Because it occurs across diverse taxa, measurements of bioluminescence can be powerful to detect and quantify organisms in the ocean. In this study, 17 years of video observations were recorded by remotely operated vehicles during surveys off the California Coast, from the surface down to 3,900 m depth. More than 350,000 observations are classified for their bioluminescence capability based on literature descriptions. The organisms represented 553 phylogenetic concepts (species, genera or families, at the most precise taxonomic level defined from the images), distributed within 13 broader taxonomic categories. The importance of bioluminescent marine taxa is highlighted in the water column, as we showed that 76% of the observed individuals have bioluminescence capability. More than 97% of Cnidarians were bioluminescent, and 9 of the 13 taxonomic categories were found to be bioluminescent dominant. The percentage of bioluminescent animals is remarkably uniform over depth. Moreover, the proportion of bioluminescent and non-bioluminescent animals within taxonomic groups changes with depth for Ctenophora, Scyphozoa, Chaetognatha, and Crustacea. Given these results, bioluminescence has to be considered an important ecological trait from the surface to the deep-sea.

Concepts: Animal, Greek loanwords, Categorization, Cnidaria, Jellyfish, Taxonomic rank, Ocean, Alpha taxonomy

39

What do you think of when you think of taxonomy? An 18th century gentlemen in breeches? Or perhaps botany drawings hung on the walls of a boutique hotel? Such old-fashioned conceptions to the contrary, taxonomy is alive today although constantly struggling for survival and recognition. The scientific community is losing valuable resources as taxonomy experts age and retire, and funding for morphological studies and species descriptions remains stagnant. At the same time, organismal knowledge (morphology, ecology, physiology) has never been more important: genomic studies are becoming more taxon focused, the scientific community is recognizing the limitations of traditional “model” organisms, and taxonomic expertise is desperately needed to fight against global biodiversity declines resulting from human impacts. There has never been a better time for a taxonomic renaissance.

Concepts: Gene, Biodiversity, Biology, Life, Genome, Species, Greek loanwords, Alpha taxonomy

39

Ocean acidification represents a threat to marine species worldwide, and forecasting the ecological impacts of acidification is a high priority for science, management, and policy. As research on the topic expands at an exponential rate, a comprehensive understanding of the variability in organisms' responses and corresponding levels of certainty is necessary to forecast the ecological effects. Here, we perform the most comprehensive meta-analysis to date by synthesizing the results of 228 studies examining biological responses to ocean acidification. The results reveal decreased survival, calcification, growth, development and abundance in response to acidification when the broad range of marine organisms is pooled together. However, the magnitude of these responses varies among taxonomic groups, suggesting there is some predictable trait-based variation in sensitivity, despite the investigation of approximately 100 new species in recent research. The results also reveal an enhanced sensitivity of mollusk larvae, but suggest that an enhanced sensitivity of early life history stages is not universal across all taxonomic groups. In addition, the variability in species' responses is enhanced when they are exposed to acidification in multi-species assemblages, suggesting that it is important to consider indirect effects and exercise caution when forecasting abundance patterns from single-species laboratory experiments. Furthermore, the results suggest that other factors, such as nutritional status or source population, could cause substantial variation in organisms' responses. Last, the results highlight a trend towards enhanced sensitivity to acidification when taxa are concurrently exposed to elevated seawater temperature.

Concepts: Biology, Life, Oceanography, Greek loanwords, Taxonomic rank, Ocean, Alpha taxonomy, Ocean acidification

26

Current taxonomic practices require corroboration from multiple lines of evidence to provide sufficient rigor for species discovery and description. However, many recently named taxa (species-families) are defined by nucleotide sequence with little or no description of the features that traditionally define higher taxa and link nucleotide-based information to the existing taxonomic system. Without knowledge of form, it may be impossible to identify conspecifics, congeners, and confamiliars of new taxa among the hundreds of specimens and described species for which nucleotide sequencing is not now, and may never be, available. Additionally, some nucleotide sequences are invariant or inconsistently differentiated between congeners; severely limiting the utility of nucleotide-based taxon definitions. Here we use serial histology of paratypes to reveal the microanatomy of internal structures and revise the definitions of the Zoanthidea taxa Corallizoanthus tsukaharai Reimer, Antipathozoanthus hickmani Reimer & Fujii, Parazoanthus darwini Reimer & Fujii, Terrazoanthus onoi Reimer & Fujii, Terrazoanthus sinnigeri Reimer & Fujii, Microzoanthus kagerou Fujii & Reimer, and Zoanthus kuroshio Reimer & Ono; examination of Mesozoanthus lilkweminensis Reimer & Sinniger failed to produce interpretable sections. The results described here, with individual measurements documented in Morphbank (collection 829724) and Encyclopedia of Life (by taxon name), indicate a notably rich diversity of form for an order that is often characterized as depauperate in morphological diversity. One prominent example is a novel marginal muscle structure (cyclically transitional) that is not observable without serial sections. These findings may renew interest in morphological characters and provide the foundation for revision of Zoanthidea higher taxa, particularly now that phylogenetic relationships for these taxa can be inferred.

Concepts: Biology, Coral, Definition, Phylogenetic nomenclature, Sequence, Phylogenetics, Anthozoa, Alpha taxonomy

15

We present a consensus classification of life to embrace the more than 1.6 million species already provided by more than 3,000 taxonomists' expert opinions in a unified and coherent, hierarchically ranked system known as the Catalogue of Life (CoL). The intent of this collaborative effort is to provide a hierarchical classification serving not only the needs of the CoL’s database providers but also the diverse public-domain user community, most of whom are familiar with the Linnaean conceptual system of ordering taxon relationships. This classification is neither phylogenetic nor evolutionary but instead represents a consensus view that accommodates taxonomic choices and practical compromises among diverse expert opinions, public usages, and conflicting evidence about the boundaries between taxa and the ranks of major taxa, including kingdoms. Certain key issues, some not fully resolved, are addressed in particular. Beyond its immediate use as a management tool for the CoL and ITIS (Integrated Taxonomic Information System), it is immediately valuable as a reference for taxonomic and biodiversity research, as a tool for societal communication, and as a classificatory “backbone” for biodiversity databases, museum collections, libraries, and textbooks. Such a modern comprehensive hierarchy has not previously existed at this level of specificity.

Concepts: Biology, Life, Species, Phylogenetic nomenclature, Cladistics, Biological classification, Alpha taxonomy, Integrated Taxonomic Information System

10

Current science evaluation still relies on citation performance, despite criticisms of purely bibliometric research assessments. Biological taxonomy suffers from a drain of knowledge and manpower, with poor citation performance commonly held as one reason for this impediment. But is there really such a citation impediment in taxonomy? We compared the citation numbers of 306 taxonomic and 2,291 non-taxonomic research articles (2009-2012) on mosses, orchids, ciliates, ants, and snakes, using Web of Science and correcting for journal visibility. For three of the five taxa, significant differences were absent in citation numbers between taxonomic and non-taxonomic papers. This was also true for all taxa combined, although taxonomic papers received more citations than non-taxonomic ones. Our results show that, contrary to common belief, taxonomic contributions do not generally reduce a journal’s citation performance and might even increase it. The scope of many journals rarely featuring taxonomy would allow editors to encourage a larger number of taxonomic submissions. Moreover, between 1993 and 2012, taxonomic publications accumulated faster than those from all biological fields. However, less than half of the taxonomic studies were published in journals in Web of Science. Thus, editors of highly visible journals inviting taxonomic contributions could benefit from taxonomy’s strong momentum. The taxonomic output could increase even more than at its current growth rate if (i) taxonomists currently publishing on other topics returned to taxonomy and (ii) non-taxonomists identifying the need for taxonomic acts started publishing these, possibly in collaboration with taxonomists. Finally, considering the high number of taxonomic papers attracted by the journal Zootaxa, we expect that the taxonomic community would indeed use increased chances of publishing in Web of Science indexed journals. We conclude that taxonomy’s standing in the present citation-focussed scientific landscape could easily improve - if the community becomes aware that there is no citation impediment in taxonomy.

Concepts: Taxonomy, Biological classification, Alpha taxonomy

8

Metagenomes provide access to the taxonomic composition and functional capabilities of microbial communities. Although metagenomic analysis methods exist for estimating overall community composition or metabolic potential, identifying specific taxa that encode specific functions or pathways of interest can be more challenging. Here we present MetAnnotate, which addresses the common question: “which organisms perform my function of interest within my metagenome(s) of interest?” MetAnnotate uses profile hidden Markov models to analyze shotgun metagenomes for genes and pathways of interest, classifies retrieved sequences either through a phylogenetic placement or best hit approach, and enables comparison of these profiles between metagenomes.

Concepts: Bacteria, Evolution, Metabolism, Biology, Organism, Series, Species, Alpha taxonomy

7

Microbial communities often exhibit incredible taxonomic diversity, raising questions regarding the mechanisms enabling species coexistence and the role of this diversity in community functioning. On the one hand, many coexisting but taxonomically distinct microorganisms can encode the same energy-yielding metabolic functions, and this functional redundancy contrasts with the expectation that species should occupy distinct metabolic niches. On the other hand, the identity of taxa encoding each function can vary substantially across space or time with little effect on the function, and this taxonomic variability is frequently thought to result from ecological drift between equivalent organisms. Here, we synthesize the powerful paradigm emerging from these two patterns, connecting the roles of function, functional redundancy and taxonomy in microbial systems. We conclude that both patterns are unlikely to be the result of ecological drift, but are inevitable emergent properties of open microbial systems resulting mainly from biotic interactions and environmental and spatial processes.

Concepts: Bacteria, Metabolism, Biology, Organism, Species, Emergence, Microorganism, Alpha taxonomy

7

BACKGROUND: A so called “taxonomic impediment” has been recognized as a major obstacle to biodiversity research for the past two decades. Numerous remedies were then proposed. However, neither significant progress in terms of formal species descriptions, nor a minimum standard for descriptions have been achieved so far. Here, we analyze the problems of traditional taxonomy which often produces keys and descriptions of limited practical value. We suggest that phylogenetics and phenetics had a subtle and so far unnoticed effect on taxonomy leading to inflated species descriptions. DISCUSSION: The term “turbo-taxonomy” was recently coined for an approach combining cox1 sequences, concise morphological descriptions by an expert taxonomist, and high-resolution digital imaging to streamline the formal description of larger numbers of new species. We propose a further development of this approach which, together with open access web-publication and automated pushing of content from journal into a wiki, may create the most efficient and sustainable way to conduct taxonomy in the future. On demand, highly concise descriptions can be gradually updated or modified in the fully versioned wiki-framework we use. This means that the visibility of additional data is not compromised, while the original species description -the first version- remains preserved in the wiki, and of course in the journal version. A DNA sequence database with an identification engine replaces an identification key, helps to avoid synonyms and has the potential to detect grossly incorrect generic placements. We demonstrate the functionality of a species-description pipeline by naming 101 new species of hyperdiverse New Guinea Trigonopterus weevils in the open-access journal ZooKeys. SUMMARY: Fast track taxonomy will not only increase speed, but also sustainability of global species inventories. It will be of great practical value to all the other disciplines that depend on a usable taxonomy and will change our perception of global biodiversity. While this approach is certainly not suitable for all taxa alike, it is the tool that will help to tackle many hyperdiverse groups and pave the road for more sustainable comparative studies, e.g. in community ecology, phylogeography and large scale biogeographic studies.

Concepts: DNA, Biodiversity, Ecology, Taxonomy, Sustainability, Identification, Open access, Alpha taxonomy