Species’ ecological preferences are often deduced from habitat characteristics thought to represent more or less optimal conditions for physiological functioning. Evolution has led to stenotopic and eurytopic species, the former having decreased niche breadths and lower tolerances to environmental variability. Species inhabiting freshwater springs are often described as being stenotopic specialists, adapted to the stable thermal conditions found in these habitats. Whether due to past local adaptation these species have evolved or have lost intra-generational...

Females and males within a species commonly have distinct reproductive roles, and the associated traits may be under perpetual divergent natural selection between the sexes if their sex-specific control has not yet evolved. We here explore whether such sexually antagonistic selection can be detected based on the magnitude of differentiation between the sexes across genome-wide genetic polymorphisms by whole-genome sequencing of large pools of female and male threespine stickleback fish. We find numerous autosomal genome...

Malaria infections occurring below the limit of detection of standard diagnostics are common in all endemic settings. However, key questions remain surrounding their contribution to sustaining transmission and whether they need to be detected and targeted to achieve malaria elimination. In this study we analyse a range of malaria datasets to quantify the density, detectability, course of infection and infectiousness of subpatent infections. Asymptomatically infected individuals have lower parasite densities on average in low transmission...

Parasite-mediated selection varying across time and space in metapopulations is expected to result in host local adaptation and the maintenance of genetic diversity in disease-related traits. However, non-adaptive processes like migration and extinction-(re)colonization dynamics might interfere with adaptive evolution. Understanding how adaptive and non-adaptive processes interact to shape genetic variability in life-history and disease-related traits can provide important insights into their evolution in subdivided populations. Here we investigate signatures of spatially fluctuating, parasite-mediated selection in...

Aim: We mapped the geographical pattern of body sizes in sphingid moths and investigated latitudinal clines. We tested hypotheses concerning their possible environmental control, i.e., effects of temperature (negative: temperature size rule or Bergmann’s rule; positive: converse Bergmann rule), food availability, robustness to starvation during extreme weather, and seasonality. Location: Old World and Australia/Pacific region Methods: Body size data of 950 sphingid species were compiled and related to their distribution maps. Focusing on body length,...

The process of ecotype formation has been invoked as an important driver of postglacial biodiversity, because many species colonized heterogeneous habitats and subsequently experienced divergent selection. Ecotype formation has been predominantly studied in outcrossing taxa, while far less attention has been paid to the implications of mating system shifts. Here we studied the genomic footprint of ecotype formation in Arabidopsis lyrata subsp. lyrata. The species colonized both rocky and sandy substrates during its postglacial range...

Abstract Background Perennity of giant rosette species in combination with a single “big bang“ reproduction followed by death of the genetic individual is relatively rare among plants. Such long-lived monocarpic plants are usually slow growing and can be found in deserts, bogs or in alpine regions of the tropics or subtropics. Due to their longevity monocarpic perennials risk to lose everything before reproduction, which make them particularly susceptible to disturbances. Because of the inherent difficulties...

In many organisms, host-associated microbial communities are acquired horizontally after birth. This process is believed to be shaped by a combination of environmental and host genetic factors. We examined whether genetic variation in animal behavior could affect the composition of the animal’s microbiota in different environments. The freshwater crustacean Daphnia magna is primarily planktonic but exhibits variation in the degree to which it browses in benthic sediments. We performed an experiment with clonal lines of...

The homeoviscous adaptation hypothesis states that the relative abundance of polyunsaturated fatty acids (PUFAs) in membrane phospholipids of ectothermic organisms decreases with increasing temperatures to maintain vital membrane properties. We reared Daphnia magna at 15°, 20°, and 25°C and increasing dietary concentrations of the long-chain PUFA eicosapentaenoic acid (EPA) to test the hypothesis that the well-documented increase in heat tolerance of high-temperature-reared Daphnia is due to a reduction in body PUFA concentrations. Heat tolerance was...

Genomic studies of parallel (or convergent) evolution often compare multiple populations diverged into two ecologically different habitats to search for loci repeatedly involved in adaptation. Because the shared ancestor of these populations is generally unavailable, the source of the alleles at adaptation loci, and the direction in which their frequencies were shifted during evolution, remain elusive. To shed light on these issues, we here use multiple populations of stickleback fish adapted to two different types...

1. Available underwater visual census methods such as line transects or point count observations are widely used to obtain community data of underwater species assemblages, despite their known pit-falls. As interest in the community structure of aquatic life is growing, there is need for more standardized and replicable methods for acquiring underwater census data. 2. Here, we propose a novel approach, Point-Combination Transect (PCT), which makes use of automated image recording by small digital cameras...

Due to the lack of recombination, asexual organisms are predicted to accumulate mutations and show high levels of within-individual allelic divergence (heterozygosity) however, empirical evidence for this prediction is largely missing. Instead, evidence of genome homogenization during asexual reproduction is accumulating. Ameiotic crossover recombination is a mechanism that could lead to long genomic stretches of loss of heterozygosity (LOH) and unmasking of mutations that have little or no effect in heterozygous state. Therefore, LOH might...