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Downy mildews caused by obligate biotrophic oomycetes result in severe crop losses worldwide. Among these pathogens, Pseudoperonospora cubensis and P. humuli, two closely related oomycetes, adversely affect cucurbits and hop, respectively. Discordant hypotheses concerning their taxonomic relationships have been proposed based on host–pathogen interactions and specificity evidence and gene sequences of a few individuals, but population genetics evidence supporting these scenarios is missing. Furthermore, nuclear and mitochondrial regions of both pathogens have been analyzed using microsatellites and phylogenetically informative molecular markers, but extensive comparative population genetics research has not been done. Here, we genotyped 138 current and historical herbarium specimens of those two taxa using microsatellites (SSRs). Our goals were to assess genetic diversity and spatial distribution, to infer the evolutionary history of P. cubensis and P. humuli, and to visualize genome-scale organizational relationship between both pathogens. High genetic diversity, modest gene flow, and presence of population structure, particularly in P. cubensis, were observed. When tested for cross-amplification, 20 out of 27 P. cubensis-derived gSSRs cross-amplified DNA of P. humuli individuals, but few amplified DNA of downy mildew pathogens from related genera. Collectively, our analyses provided a definite argument for the hypothesis that both pathogens are distinct species, and suggested further speciation in the P. cubensis complex.
Die Geobotanik oder Vegetationskunde mit all ihren Teildisziplinen (u.a. Biogeographie, Pflanzensoziologie, Pflanzenökologie, Biozönologie, Floren- und Vegetationsgeschichte, Paläoökologie) ist eine der wichtigsten ganzheitlichen Zugänge zur Biologie insgesamt und die Forschungsdisziplin, welche die Aufgabe hat, zeitliche und räumliche Muster der Diversität in der Pflanzenwelt zu dokumentieren, zu analysieren, visualisieren und zu interpretieren. Die Biodiversität ist zu einem Schlüsselbegriff der ökologischen wie auch geobotanischen Forschung geworden. Die belebte Welt unseres Planeten ist von unglaublicher Vielfalt. Die Anzahl bekannter Arten an Pflanzen, Tieren und Mikroorganismen wird derzeit auf 1,4 Millionen veranschlagt, 5 bis 15 Millionen Arten werden global geschätzt. Diese Zahl lässt jedoch viele Plünderte oder Tausende von bislang noch nicht oder nur schlecht bestimmten Arten in gewissen Organismengruppen (z. B. Mikroorganismen) unberücksichtigt, welche bislang noch nicht oder nur unzureichend erfasst und beschrieben sind. Die systematische Erfassung aller Arten in international angelegten und intensiv finanzierten Arten erfassungsprogrammen ist eine notwendige Zukunftsaufgabe. Die Einbindung der Pflanzen und Mikroorganismen in die natürlichen Ökosysteme, ihr euryökes oder stenökes Standortverhalten, die Erfassung ihrer Konkurrenzkraft und ihrer Migrationsfähigkeit sind beispielsweise vordergründige Aufgaben. Neben den heute bekannten Arten hat wohl ein Mehrfaches dieser Zahl - vielleicht Millionen oder gar Milliarden - in der Vergangenheit gelebt. Sie sind heute ausgestorben, ohne je einmal lebend beschrieben worden zu sein. Nur ein kleiner Rest ist uns als Fossilien erhalten. Die Biodiversität unserer heutigen Welt muss also verstärkt kausal aus paläoökologischer Sicht beleuchtet werden. Auch die natürliche Variabilität des Klimas, die Geodiversität und die Biodiversität sind als Schätze der heutigen Ökosysteme der Erde zu betrachten. Die Rekonstruktion natürlicher klimatischer Abläufe, die genaue Erfassung der Variabilität und der Schwankungsintensität des natürlichen Klimas und der gegebenenfalls anthropogenen Klimaerwärmung sind vordergründige Aufgaben hochspezialisierter, interdisziplinärer Forschung, an denen die Geobotanik ihren zukommenden Anteil haben wird. Dies wird an einigen Beispielen verdeutlicht. Vor diesem Hintergrund sollen einige Aspekte vordergründiger Probleme des 21. Jahrhunderts aus globaler bis lokaler Perspektive diskutiert und schließlich die Rolle beleuchtet werden, welche geobotanische Forschung zu Beginn dieses neuen Jahrhunderts einnehmen könnte.
Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process.
Attractiveness ratings for musicians and non-musicians: An evolutionary-psychology perspective
(2019)
From an evolutionary perspective, musical behavior such as playing an instrument can be considered as part of an individual’s courting behavior. Playing a musical instrument or singing might fulfill a function similar to that of a bird’s colored feathers: attracting attention. Therefore, musicians may be rated as more attractive than non-musicians. In an online survey, 137 volunteers (95 female) with ages ranging from 16 to 39 years rated the attractiveness of fictitious persons of the opposite sex described in short verbal profiles. These profiles differed with respect to whether the described person made music or not. Additionally, the musicians’ profiles varied with regard to whether the described person played music or sang in public or in private only. Results show that musicians’ profiles were not generally rated as more attractive than non-musicians’, but attractiveness did vary according to setting: private musicians were rated as most attractive, followed by non-musicians and public musicians. Furthermore, results indicate that participants who played a musical instrument or sang themselves gave higher ratings to profiles of musicians. But for participants who do not make music themselves, higher attractiveness ratings for musicians playing instruments or sing in private settings were found. These results indicate that the impression of sharing a common interest (making music) and furthermore making music in private instrumental settings seems to make people attractive to other people. No additional support for the sexual selection hypotheses for the evolution of music was provided by the current results. The musical status of the rater affected his or her judgements, with musicians rating other people as more attractive if they share the common interest in making music. Not the display of being a musician seems to be critical for attractiveness ratings but the perceived or imagined similarity by the rater created by information on musicality, fostering the theoretical significance of the communication aspect of music.
The taxonomy of cyclostome bryozoans is founded on characters of the skeleton, but molecular sequence data have increasingly shown that established higher taxa are not monophyletic. Here we describe the skeletal morphology of a new species from Guadeloupe (French West Indies) with erect ramose colonies consisting of long, curved zooids that are typical of the suborder Cerioporina among living cyclostomes. However, molecular evidence from nuclear ribosomal RNA genes 18S and 28S places the new taxon in the suborder Rectangulata, where this colony-form has not been previously recorded. It nests firmly within the genus Disporella Gray, 1848, in a strongly supported clade that also includes Plagioecia patina (Lamarck, 1816) (Tubuliporina) and the sister taxa Doliocoitis cyanea Gordon & Taylor, 2001 (Rectangulata) and Favosipora rosea Gordon & Taylor, 2001 (Cerioporina). The short and robust branches of the new Guadeloupe cyclostome, here named Disporella guada Harmelin, Taylor & Waeschenbach sp. nov., are well adapted to life in shallow rocky sites exposed to severe wave action, which appear to be its exclusive habitat.
A new family, Electrocambalidae fam. nov. of the suborder Cambalidea is described from Cretaceous Burmese amber based on two new genera, Electrocambala gen. nov. and Kachincambala gen. nov. with four new species, Electrocambala ornata gen. et sp. nov., E. cretacea gen. et sp. nov., Kachincambala muelleri gen. et sp. nov. and K. distorta gen. et sp. nov. The specimens are described combining classical light microscopy with drawings and photography, and modern micro-computed tomography (μCT). Morphological characters otherwise obscured are examined and visualized by creating volume renderings and 3D-segmentations from μCT data. Electrocambalidae fam. nov. is characterized by the following character combination: (1) a forward shift of leg pair 3, resulting in an apparently legless 3rd body ring, (2) presence of metazonital setae, and (3) extensive pilosity on the head. Although some of these characters are shared with other Juliformia they are unique in this combination. The described fossils are the oldest and first Mesozoic Spirostreptida and Cambalidea known and ca 70 million years older than previous records of the group.
Inhibitors against the NS3-4A protease of hepatitis C virus (HCV) have proven to be useful drugs in the treatment of HCV infection. Although variants have been identified with mutations that confer resistance to these inhibitors, the mutations do not restore replicative fitness and no secondary mutations that rescue fitness have been found. To gain insight into the molecular mechanisms underlying the lack of fitness compensation, we screened known resistance mutations in infectious HCV cell culture with different genomic backgrounds. We observed that the Q41R mutation of NS3-4A efficiently rescues the replicative fitness in cell culture for virus variants containing mutations at NS3-Asp168. To understand how the Q41R mutation rescues activity, we performed protease activity assays complemented by molecular dynamics simulations, which showed that protease-peptide interactions far outside the targeted peptide cleavage sites mediate substrate recognition by NS3-4A and support protease cleavage kinetics. These interactions shed new light on the mechanisms by which NS3-4A cleaves its substrates, viral polyproteins and a prime cellular antiviral adaptor protein, the mitochondrial antiviral signaling protein MAVS. Peptide binding is mediated by an extended hydrogen-bond network in NS3-4A that was effectively optimized for protease-MAVS binding in Asp168 variants with rescued replicative fitness from NS3-Q41R. In the protease harboring NS3-Q41R, the N-terminal cleavage products of MAVS retained high affinity to the active site, rendering the protease susceptible for potential product inhibition. Our findings reveal delicately balanced protease-peptide interactions in viral replication and immune escape that likely restrict the protease adaptive capability and narrow the virus evolutionary space.
Five new species in four new genera from Western Australia are described. All species have valve characters that are reminiscent of the genus Heterocypris Claus, 1892 and also have similar valve outlines, with highly arched valves. However, all species have a hemipenis morphology that is totally different from the typical form in Heterocypris. In Patcypris gen. nov. (with type species P. outback gen. et sp. nov.), the lateral lobe is large and shaped as a pickaxe, while the medial lobe is divided into two distal lobes. Trilocypris gen. nov. (with type species T. horwitzi gen. et sp. nov.) is characterised by a hemipenis that has three, instead of two, distal lobes. In Bilocypris gen. nov. (with type species B. fortescuensis gen. et sp. nov. and a second species, B. mandoraensis gen. et sp. nov.), the lateral lobe of the hemipenis is spatulate, rather than boot-shaped, and the medial lobe is bilobed. Billcypris gen. nov. (with type species B. davisae gen. et sp. nov.) has a large and sub-rectangular lateral lobe and a pointed medial lobe. We discuss the taxonomic value of the traditional and new morphological characters and speculate that the diversity of this cluster of genera and species may be greater than currently known.
The genus Thlaspi has been variously subdivided since its description by Linnaeus in 1753, but due to similarities in fruit shape several segregates have still not gained broad recognition, despite the fact that they are not directly related to Thlaspi. This applies especially to segregates now considered to belong to the tribe Coluteocarpeae, which includes several well-studied taxa, e.g., Noccaea caerulescens (syn. Thlaspi caerulescens), and the widespread Microthlaspi perfoliatum (syn. Thlaspi perfoliatum). The taxonomy of this tribe is still debated, as a series of detailed monographs on Coluteocarpeae was not published in English and a lack of phylogenetic resolution within this tribe was found in previous studies. The current study presents detailed phylogenetic investigations and a critical review of morphological features, with focus on taxa previously placed in Microthlaspi. Based on one nuclear (ITS) and two chloroplast (matK, trnL-F) loci, four strongly supported major groups were recovered among the Coluteocarpeae genera included, corresponding to Ihsanalshehbazia gen. nov., Friedrichkarlmeyeria gen. nov., Microthlaspi s.str., and Noccaea s.l. In addition, two new species of Microthlaspi, M. sylvarum-cedri sp. nov. and M. mediterraneo-orientale sp. nov., were discovered, which are well supported by both morphological and molecular data. Furthermore, M. erraticum comb. nov. (diploid) and M. perfoliatum s.str. (polyploid) were shown to be distinct species, phylogenetically widely separate, but with some overlap in several morphological characters. Detailed descriptions, notes on taxonomy, geographical distribution, and line drawings for the new species and each species previously included in Microthlaspi are provided. In addition, the current taxonomic state of the tribe Coluteocarpeae is briefly discussed and it is concluded that while several annual taxa are clearly distinct from Noccaea, many perennial taxa, after thorough phylogenetic and morphological investigations, may have to be merged with this genus.
Three fossil leafhopper inclusions from Eocene Baltic amber, representing three new extinct genera and species, are described and illustrated. Eomegophthalmus lithuaniensis gen. et sp. nov. is tentatively placed in Megophthalminae, although it may represent the stem group from which Megophthalminae, Ulopinae, and Membracidae arose. Xestocephalites balticus gen. et sp. nov. and Brevaphrodella nigra gen. et sp. nov. are placed in Aphrodinae: Xestocephalini based on the structure of the head, leg chaetotaxy, and male genital capsule. These new genera and species represent the oldest known representatives of their respective subfamilies and the latter is the oldest known brachypterous adult leafhopper.