evolutionary uniqueness
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Urbanization, one of the most important anthropogenic impacts on Earth, is rapidly expanding worldwide. This expansion of urban land-covered areas is known to significantly reduce different components of biodiversity. However, the global evidence for this effect is mainly focused on a single diversity measure (species richness) with a few local or regional studies also supporting reductions in functional diversity. We have used birds, an important ecological group that has been used as surrogate for other animals, to investigate the hypothesis that urbanization reduces the global taxonomical and/or evolutionary diversity. We have also explored whether there is evidence supporting that urban bird communities are evolutionarily homogenized worldwide in comparison with nonurban ones by means of using evolutionary distinctiveness (how unique are the species) of bird communities. To our knowledge, this is the first attempt to quantify the effect of urbanization in more than one single diversity measure as well as the first time to look for associations between urbanization and phylogenetic diversity at a large spatial scale. Our findings show a strong and globally consistent reduction in taxonomic diversity in urban areas, which is also synchronized with the evolutionary homogenization of urban bird communities. Despite our general patterns, we found some regional differences in the intensity of the effect of cities on bird species richness or evolutionary distinctiveness, suggesting that conservation efforts should be adapted locally. Our findings might be useful for conservationists and policymakers to minimize the impact of urban development on Earth's biodiversity and help design more realistic conservation strategies.
- MeSH
- biodiverzita * MeSH
- fylogeneze MeSH
- ptáci * MeSH
- urbanizace * MeSH
- velkoměsta MeSH
- zachování přírodních zdrojů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- velkoměsta MeSH
The evolutionary distinctiveness (ED) score is a measure of phylogenetic isolation that quantifies the evolutionary uniqueness of a species. Here, we compared the ED score of parasitic and non-parasitic cuckoo species world-wide, to understand whether parental care or parasitism represents the largest amount of phylogenetic uniqueness. Next, we focused only on 46 cuckoo species characterized by brood parasitism with a known number of host species, and we explored the associations among ED score, number of host species and breeding range size for these species. We assessed these associations using phylogenetic generalized least squares (PGLS) models, taking into account the phylogenetic signal. Parasitic cuckoo species were not more unique in terms of ED than non-parasitic species. However, we found a significant negative association between the evolutionary uniqueness and host range and a positive correlation between the number of host species and range size of parasitic cuckoos, probably suggesting a passive sampling of hosts by parasitic species as the breeding range broadens. The findings of this study showed that more generalist brood parasites occupied very different positions in a phylogenetic tree, suggesting that they have evolved independently within the Cuculiformes order. Finally, we demonstrated that specialist cuckoo species also represent the most evolutionarily unique species in the order of Cuculiformes.
xx, 523 s. : il.
Evoluce lidského jazyka je předmětem sporů. Hauserova-Fitchova-Chomského hypotéza rozlišuje jazykovou vlohu v širokém slova smyslu, zahrnující senzoricko-motorický systém a systém pojmů a záměrů a jazykovou vlohu v úzkém slova smyslu, ta je výpočetním systémem rekurze a má být jedinou výlučně lidskou složkou jazyka. Hypotéza je předmětem rozsáhlé kritiky, například proto, že nezohledňuje ne-rekurzivní aspekty gramatiky, neodpovídá anatomii a neuronální kontrole lidského vokálního traktu. Arbibova-Rizzolatiho hypotéza vychází z objevu systému zrcadlových neuronů a formuluje řadu domněnek o proměnách jak uvnitř tohoto systému, tak mimo něj, jejichž výsledkem je „mozek připravený pro jazyk“. Christiansenova-Chaterova hypotéza dokazuje, že jazyk je utvářen mozkem, nikoli naopak, univerzální gramatika podle ní neexistuje.
The evolution of human language is a matter of controversy. Hauser-Fitch-Chomsky's hypothesis distinguishes between faculty of language in the broad sense, which includes sensory-motor system and conceptual-intentional system, and faculty of language in the narrow sense (FLN), which is a computational system for recursion. FLN should be the only unique human component of the faculty of language. This hypothesis is subject to much criticism: it ignores non-recursive aspects of grammar, is inconsistent with the anatomy and neural control of the human vocal tract e.g. Arbib-Rizzolati's hypothesis starts with the “mirror system” and offers hypotheses on evolutionary changes within and outside the mirror system which may have equipped our ancestors with a language-ready brain. Christiansen – Chater's hypothesis states that a language is shaped by the brain, biologically determined universal grammar is not evolutionary viable: the language has been shared to fit the brain, rather than vice versa.
... \'Intelligence\' has long been considered to be a feature unique to human beings, giving us the capacity ... ... However, like all our other features, intelligence is a product of evolutionary change. ... ... study of primates, our closest non-human relatives, giving strong impetus to the case for an \'evolutionary ... ... -- Further reading -- How to reconstruct evolutionary history -- Linnean taxomony -- Evolution -- Evolutionary ... ... taxomony: cladistics -- Molecular taxomony -- 11 imate and human evolutionary relationships -- Inventing ...
ix, 266 s. : il. ; 24 cm
Background: Refugia are island-like habitats that are linked to long-term environmental stability and, as a result, high endemism. Conservation of refugia and endemism hotspots should be based on a deep ecological and evolutionary understanding of their functioning, which remains limited. Although functional traits can provide such insights, a corresponding, coherent framework is lacking. Proposed Framework: Plant communities in refugia and endemism hotspots should, due to long-term environmental stability, display unique functional characteristics linked to distinct phylogenetic patterns. Therefore, such communities should be characterized by a functional signature that exhibits: (1) distinct values and combinations of traits, (2) higher functional diversity and (3) a prevalence of similar traits belonging to more distantly related lineages inside, compared to outside, of endemism hotspots and refugia. While the limited functional trait data available from refugia and endemism hotspots do not allow these predictions to be tested rigorously, three potential applications of the functional signature in biogeography and conservation planning are highlighted. Firstly, it allows the functional characteristics of endemism hotspots and refugia to be identified. Secondly, the strength of the functional signature can be compared among these entities, and with the surrounding landscape, to provide an estimate of the capacity of endemism hotspots and refugia to buffer environmental changes. Finally, the pattern of the functional signature can reveal ecological and evolutionary processes driving community assembly and functioning, which can assist in predicting the effect of environmental changes (e.g. climate, land-use) on communities in endemism hotspots and refugia. Conclusion: The proposed functional signature concept allows the systematic integration of plant functional traits and phylogeny into the study of endemism hotspots and refugia, but more data on functional traits in these entities are urgently needed. Overcoming this limitation would facilitate rigorous testing of the proposed predictions for the functional signature, advancing the eco-evolutionary understanding of endemism hotspots and refugia.
The Neotropical fish, Hoplias malabaricus, is one of the most cytogenetically studied fish taxon with seven distinct karyomorphs (A-G) comprising varying degrees of sex chromosome differentiation, ranging from homomorphic to highly differentiated simple and multiple sex chromosomes. Therefore, this fish offers a unique opportunity to track evolutionary mechanisms standing behind the sex chromosome evolution and differentiation. Here, we focused on a high-resolution cytogenetic characterization of the unique XX/XY1Y2 multiple sex chromosome system found in one of its karyomorphs (G). For this, we applied a suite of conventional (Giemsa-staining, C-banding) and molecular cytogenetic approaches, including fluorescence in situ hybridization FISH (with 5S and 18S rDNAs, 10 microsatellite motifs and telomeric (TTAGGG) n sequences as probes), comparative genomic hybridization (CGH), and whole chromosome painting (WCP). In addition, we performed comparative analyses with other Erythrinidae species to discover the evolutionary origin of this unique karyomorph G-specific XY1Y2 multiple sex chromosome system. WCP experiments confirmed the homology between these multiple sex chromosomes and the nascent XX/XY sex system found in the karyomorph F, but disproved a homology with those of karyomorphs A-D and other closely related species. Besides, the putative origin of such XY1Y2 system by rearrangements of several chromosome pairs from an ancestral karyotype was also highlighted. In addition, clear identification of a male-specific region on the Y1 chromosome suggested a differential pattern of repetitive sequences accumulation. The present data suggested the origin of this unique XY1Y2 sex system, revealing evidences for the high level of plasticity of sex chromosome differentiation within the Erythrinidae.
- MeSH
- hybridizace in situ fluorescenční MeSH
- karyotyp MeSH
- malování chromozomů MeSH
- mikrosatelitní repetice MeSH
- molekulární evoluce * MeSH
- pohlavní chromozomy genetika MeSH
- repetitivní sekvence nukleových kyselin MeSH
- ryby genetika metabolismus MeSH
- srovnávací genomová hybridizace MeSH
- telomery MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Despite their complex evolutionary histories, aquatic plants are highly underrepresented in contemporary biosystematic studies. Of them, the genus Callitriche is particularly interesting because of such evolutionary features as wide variation in chromosome numbers and pollination systems. However, taxonomic difficulties have prevented broader investigation of this genus. In this study we applied flow cytometry to Callitriche for the first time in order to gain an insight into evolutionary processes and genome size differentiation in the genus. Flow cytometry complemented by confirmation of chromosome counts was applied to an extensive dataset of 1077 Callitriche individuals from 495 localities in 11 European countries and the USA. Genome size was determined for 12 taxa. The results suggest that many important processes have interacted in the evolution of the genus, including polyploidization and hybridization. Incongruence between genome size and ploidy level, intraspecific variation in genome size, formation of autotriploid and hybridization between species with different pollination systems were also detected. Hybridization takes place particularly in the diploid-tetraploid complex C. cophocarpa-C. platycarpa, for which the triploid hybrids were frequently recorded in the area of co-occurrence of its parents. A hitherto unknown hybrid (probably C. hamulata × C. cophocarpa) with a unique chromosome number was discovered in the Czech Republic. However, hybridization occurs very rarely among most of the studied species. The main ecological preferences were also compared among the taxa collected. Although Callitriche taxa often grow in mixed populations, the ecological preferences of individual species are distinctly different in some cases. Anyway, flow cytometry is a very efficient method for taxonomic delimitation, determination and investigation of Callitriche species, and is even able to distinguish homoploid taxa and identify introduced species.
Together with plague, smallpox and typhus, epidemics of dysentery have been a major scourge of human populations for centuries(1). A previous genomic study concluded that Shigella dysenteriae type 1 (Sd1), the epidemic dysentery bacillus, emerged and spread worldwide after the First World War, with no clear pattern of transmission(2). This is not consistent with the massive cyclic dysentery epidemics reported in Europe during the eighteenth and nineteenth centuries(1,3,4) and the first isolation of Sd1 in Japan in 1897(5). Here, we report a whole-genome analysis of 331 Sd1 isolates from around the world, collected between 1915 and 2011, providing us with unprecedented insight into the historical spread of this pathogen. We show here that Sd1 has existed since at least the eighteenth century and that it swept the globe at the end of the nineteenth century, diversifying into distinct lineages associated with the First World War, Second World War and various conflicts or natural disasters across Africa, Asia and Central America. We also provide a unique historical perspective on the evolution of antibiotic resistance over a 100-year period, beginning decades before the antibiotic era, and identify a prevalent multiple antibiotic-resistant lineage in South Asia that was transmitted in several waves to Africa, where it caused severe outbreaks of disease.
- MeSH
- bacilární dyzentérie epidemiologie dějiny mikrobiologie MeSH
- bakteriální léková rezistence MeSH
- celosvětové zdraví MeSH
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- fylogeografie * MeSH
- genom bakteriální MeSH
- lidé MeSH
- molekulární epidemiologie MeSH
- molekulární evoluce * MeSH
- sekvenční analýza DNA MeSH
- séroskupina * MeSH
- Shigella dysenteriae klasifikace genetika izolace a purifikace MeSH
- Check Tag
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
Characterisation of G protein-coupled receptors (GPCR) relies on the availability of a toolbox of ligands that selectively modulate different functional states of the receptors. To uncover such molecules, we explored a unique strategy for ligand discovery that takes advantage of the evolutionary conservation of the 600-million-year-old oxytocin/vasopressin signalling system. We isolated the insect oxytocin/vasopressin orthologue inotocin from the black garden ant (Lasius niger), identified and cloned its cognate receptor and determined its pharmacological properties on the insect and human oxytocin/vasopressin receptors. Subsequently, we identified a functional dichotomy: inotocin activated the insect inotocin and the human vasopressin V1b receptors, but inhibited the human V1aR. Replacement of Arg8 of inotocin by D-Arg8 led to a potent, stable and competitive V1aR-antagonist ([D-Arg8]-inotocin) with a 3,000-fold binding selectivity for the human V1aR over the other three subtypes, OTR, V1bR and V2R. The Arg8/D-Arg8 ligand-pair was further investigated to gain novel insights into the oxytocin/vasopressin peptide-receptor interaction, which led to the identification of key residues of the receptors that are important for ligand functionality and selectivity. These observations could play an important role for development of oxytocin/vasopressin receptor modulators that would enable clear distinction of the physiological and pathological responses of the individual receptor subtypes.
- MeSH
- antagonisté antidiuretického hormonu izolace a purifikace metabolismus MeSH
- Formicidae MeSH
- lidé MeSH
- mutační analýza DNA MeSH
- neuropeptidy genetika izolace a purifikace metabolismus MeSH
- receptory vasopresinů agonisté MeSH
- rekombinantní proteiny genetika izolace a purifikace metabolismus MeSH
- substituce aminokyselin MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
