Department Aquatic Ecology

In the Afrotropical Region, Sphyracephala beccarii (Rondani) and S. munroi Curran are found, the former just extending into the Palaearctic Region. In the latter region, S. babadjanidesi Zaitzev occurs in the Balkan and Caucasus Regions and S. nigrimana Loew in Far Eastern Russia and North-Eastern China. The European stalk-eyed fly S. europaea Papp & Földvári is proposed as junior synonym of the Eurasian stalk-eyed fly S. babadjanidesi. In North America S. brevicornis (Say) and S. subbifasciata Fitch occur. The four true Holarctic Sphyracephala are shown to reach their northern limits between 45°30'N and 48°20'N. These species hibernate and show characteristic clustering behaviour in spring and autumn. The four Palaearctic and Afrotropical Sphyracephala are redescribed and extensively illustrated. A key is given to all nine Sphyracephala presently recognised. The subdivisions within the genus are discussed. A cladogram, based on morphological, molecular, wing morphometric and allometric considerations, is presented. It shows the two species groups recognised. Each species group is divided into two subtaxa. Geometric morphometric analysis supports the grouping in four subtaxa as well as the synonymy of S. babadjanidesi and S. europaea. In Sphyracephala, both sexual monomorphism and dimorphism with relation to eye span occur. The allometric lines for males and females of eight species are compared. A clear link is found between allometric slopes and the four subtaxa distinguished. In Sphyracephala, female-biased, balanced, and male-biased sex ratios are found. A remarkable case of female-biased sex ratio distortion is reported for Sphyracephala beccarii. In Continental Africa and the Arabian Peninsula, a balanced sex ratio was found, while in Madagascar a female-biased 2:1 ratio was found. This represents the first case of a female-biased sex-ratio in a geographically isolated population of a monomorphic diopsid.

The spatial distribution of genetic diversity within a species' range reflects its past demographic history, and its knowledge is essential to better understand the limits of species ranges and to predict range shifts in response to a changing environment. We present GenDivRange, a unified dataset of published geo-referenced estimates of genetic diversity for 1,109 species, each represented by at least five populations placed on their range maps estimated from Global Biodiversity Information Facility (GBIF) observations. A total of 19,173 populations across the globe and from most major taxa, covering terrestrial, freshwater, and marine organisms, are included. At least one of the three genetic diversity estimates is available for each study: expected heterozygosity, Nei's gene diversity, or allelic richness, mostly estimated from microsatellite markers. Additionally, the dataset contains the detailed taxonomy, biome, breeding, and adult habitat of each species.

Global health is threatened by the rise of antibiotic resistance. Bacteria of the Mycobacterium tuberculosis complex (Mtbc) are a major contributor to this antibiotic crisis, with about 450,000 new multidrug-resistant tuberculosis (MDR-TB) cases per year. This study investigates resistance evolution by defining the resistance mutant selection window (MSW) for the important MDR-TB treatment drugs moxifloxacin and bedaquiline. We employed a combination of long-term in vitro experiments supplemented with mathematical modeling that combined pharmacodynamics with population genetics. We assessed resistance selection at concentrations below the minimum inhibitory concentration (MIC), the MSW and fitness cost of eight mutant clones with different resistance-associated variants. Both computational and experimental results show that mutant clone populations are selected far below the MIC, leading to a major growth advantage of resistant populations under weak selection pressure. An eighth of the MIC was enough to enrich mutant clone populations in the short term (five bacterial passages or 20 generations), even in mutant clones with a major competitive fitness loss. In fact, gyrA, gyrB and most Rv0678 mutations have virtually no effect on the bacteria's competitive fitness in vitro. This work highlights the risk that ineffective drug delivery and dosing can lead to the emergence of resistance.