Ecology and Evolution

The complex speciation–richness relationship in a simple neutral model: as the number of communities in the metacommunity grows, the relationship changes from positive to negative. When we model the metacommunity as a network with only a few communities, the most connected communities are both more diverse and witness more speciation events, but the opposite is true for metacommunities composed of a great number of communities.

We studied the effect of inbreeding rate on offspring production and extinction of experimental Drosophila littoralis populations from low to increasing levels of inbreeding. The results suggest that highly deleterious recessive alleles can be purged from small populations, and that at low levels of inbreeding selection is more efficient when inbreeding is slow. However, purging did not protect the small populations from eventual genetic deterioration and extinction.

Local populations of Rhinogobius sp. YB above waterfalls found in Iriomote Island were evolved independently from amphidromous R. brunneus, suggesting parallel evolution. Genetic distance between each Rhinogobius sp. YB local population and R. brunneus was significantly correlated with waterfall height due to the constant geological erosion. Simultaneous multiple phases of allopatric/parallel evolution of the goby can be seen because of variations in waterfall height.

Ecological gradients have been shown to shape species diversity, abundance, and interactions. Here, we show that during radiation into high altitude, butterfly species encounter low plant species richness. This, concomitant with plants being less resistant in altitude, has favored increased butterfly polyphagy when compared to low altitude species.

We assess the phylogeny of the enigmatic virus family, Filoviridae, which includes Ebola and Marburg viruses. This family has not seen detailed phylogenetic study before; our analyses show the existence of a second species – or at least a distinct lineage – of Marburg virus. Appreciation of the distinctiveness of this lineage has important implications for understanding the biogeography and host associations of the filoviruses.

Evolutionary quantitative genetic studies increasingly often attempt to infer pleiotropic constraints to evolution based on the eigenvectors of the G matrix. I here use models of genetic architecture to show that this research strategy is flawed because of potential instability in the eigenvectors of G, and their disconnect to genetic architecture arising from spectral decomposition.

The objective of this experiment was to identify links between plant C exudation and belowground C and N turnover caused by rhizosphere priming effects. Our findings suggest that increased belowground allocation of plant C results in a massive stimulation of soil organic matter decomposition, with concurrent release of plant available N. The increase could be assigned to rhizosphere priming effects, and the extent of priming seems to be intimately linked to C and N availability.

Jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta var. latifolia) are two North American boreal hard pines that hybridize in their zone of contact in western Canada. The main objective of this study was to characterize their patterns of introgression resulting from past and recent gene flow, using cytoplasmic markers having contrasted maternal and paternal inheritance.

Acropora rongelapensis is a recently described species of Acropora. New population genetic data suggest that despite an exceedingly low global population size, this rare species has high genetic diversity resulting from a hybrid ancestry.

This manuscript describes the population structure and extent of hybridization between two mosquito sibling species, Culex pipiens and Culex quinquefasciatus, in the islands of Macaronesia. These species are important vectors of disease. The observed population structure reflects both the biogeography of the islands and historical aspects of human peopling.

Adult female of Sceloporus grammicus from Tepeapulco, Hidalgo, México. Interpopulation variation, Life history, Reproduction and sexual dimorphism in lizard.

Male condition is likely to be correlated with male acoustic signal traits, which signal male quality and provide choosy females indirect benefits. We tested whether stressing food plants influence acoustic signal traits of males via a condition-dependent expression of these traits. We suggest that food plant stress and therefore food plant quality led to shifts in loudness of male grasshopper songs via body condition changes.

Life history leaves an evolutionary signal in long-term density feedbacks estimated from census data across species of vertebrates, invertebrates, and plants. Where there is a lack of detailed demographic data, broad life-history information can inform about a population's rebound capacity from low numbers and propensity to fluctuate.

Fungal communities are playing key roles in ecosystem functioning. However, only scarce knowledge exists about their assemblages in roots and soil of biomass plantations. The goal of this study was to analyze fungal biodiversity in their belowground habitats and to gain information on the ectomycorrhizal (ECM) fungal colonization strategy. In a 2-year-old plantation, fungal communities in soil and roots of transgenetically modified poplars were analyzed by 454 pyrosequencing using rDNA ITS1 region as the target region.

The native range of the honeybee Apis mellifera encompasses Europe, Africa, and the Middle East, but its origins are unclear. This analysis of >1000 single-nucleotide polymorphism markers from individuals across this range suggests that previous reports of an African origin are not well supported, favoring instead an origin in Asia, where all of the other Apis species are found.

At methane seeps along the Cascadian margin, sulfide-tolerant dorvilleid annelids dominate the benthos. A combination of preadaptation to high-sulfide and low-oxygen conditions, release from predation and competition, and resource specialization probably enabled multiple lineages of these worms to invade cold seeps and radiate into a diverse species assemblage.

If some predator species are capable of coping with the secondary defenses of prey, selection can favor reduced conspicuousness of signaling via reduced detectability or recognition of the prey. In this study, we combine data collected during three large-scale field experiments to assess whether the variation in avian predator species affects the predation pressure on warningly and non-warning colored artificial snakes. Predation pressure varied among locations and interestingly, if common buzzards were abundant, there were disadvantages of warning signaling snakes.

We tested whether songs or contact calls of silvereyes (Zosterops lateralis) might be subject to convergent cultural evolution by comparing syllable repertoires of geographically dispersed urban and rural population pairs throughout southeastern Australia. Results of meme comparisons and partial redundancy analysis of repertoires provided support for the role of acoustic adaptation in shaping urban silvereye dialects.

Tropical reef macroalgae play an important role in the coral reef ecosystem. We measured the effect of elevated nutrient concentrations on macro algae physiology by linking the relative element content of organisms to algal growth rate and investment in ribosomes. We found that these coral reef algae do not maintain the stoichiometry that would facilitate maximum growth rates but instead invest in luxury uptake of phosphate for future use in a unique adaptation to the low and patchy nutrient environment in many tropical waters.

In this study, with genome-wide in-depth investigation, 31 Poplar KT/HAK/KUP transporter genes including six pairs of tandem duplicated and eight pairs of segmental duplicated paralogs have been identified, suggesting segmental and tandem duplication events contributed to the expansion of this family in Poplar.

Western corn rootworm (Diabrotica virgifera) (WCR) depends on the continuous availability of corn. Broad adoption of annual crop rotation between corn (Zea mays) and nonhost soybean (Glycine max) exploited WCR biology to provide excellent WCR control, but this practice dramatically reduced landscape heterogeneity in East-central Illinois and imposed intense selection pressure. This selection resulted in behavioral changes and ‘rotation-resistant’ (RR) WCR adults. Our data strongly suggest that higher constitutive activity of cathepsin L and differential gene expression are components of the mechanism that enables U.S. Corn Belt populations of WCR that enter soybean fields to circumvent soybean defenses, and thus, crop rotation. These new insights into the mechanism of WCR tolerance of soybean herbivory transcend the issue of RR WCR diagnostics and management to link changes in insect gut proteolytic activity and behavior with landscape heterogeneity. The RR WCR illustrates how agro-ecological factors can affect the evolution of insects in human-altered ecosystems.

The natterjack toad (Bufo calamita) is distributed across a wide geographic range that qualifies the species as interesting for a geographic analysis of its genetic variability. We analyzed the altitudinal and latitudinal genetic variation in B. calamita using genetic diversity parameters. Genetic variability in B. calamita along its wide altitudinal and latitudinal geographic distribution mainly reflects the colonization history of the species after the last glacial period.

In a spatially heterogeneous environment, the rate at which individuals move among habitats affects whether selection favors phenotypic plasticity or genetic differentiation, with high dispersal rates favoring trait plasticity. We examined the effects of their joint evolution on selection for plasticity using an individual-based computer simulation model. When dispersal rate and trait plasticity evolve jointly, the system tends to dichotomous outcomes of either high trait plasticity and high dispersal, or low trait plasticity and low dispersal.

Global amphibian declines suggest a major shift in the amount and quality of habitat for these sensitive taxa. The northern leopard frog (Rana [Lithobates] pipiens] has undergone significant declines particularly in the western United States and Canada. The western Nevada populations are geographically isolated and highly differentiated from each other and populations in eastern Nevada.

Phylogenetic analyses of the Black Tiger shrimp (Penaeus monodon) from its natural range of Indo-Pacific distribution including the South Pacific islands of Fiji, Palau, and Papua New Guinea (PNG) were conducted. The data identified that shrimp from Fiji were genetically distinct, but shrimp from Palau and PNG were genetically similar to shrimp indigenous to Southeast Asia and eastern Australia, respectively. The data supported shrimp from the South Pacific (Palau, PNG, and Fiji) being colonized relatively recently by neighboring populations closest in proximity.

The extent and duration of sea-ice habitats used by Pacific walruses (Odobenus rosmarus divergens) are diminishing resulting in altered walrus behavior, mortality, and distribution. Associated stressors were modeled as most likely-case, worst-case, and best-case scenarios for the mid- and late-21st century, resulting in four comprehensive working hypotheses that can help identify and prioritize management and research projects, identify comprehensive mitigation actions, and guide monitoring programs to track future developments and adjust programs as needed.