Diversifying selection drives parallel evolution of gill raker number and body size along the speciation continuum of European whitefish.

Adaptive radiation is the evolution of ecological and phenotypical diversity. It arises via ecological opportunity that promotes the exploration of underutilized or novel niches mediating specialization and reproductive isolation. The assumed precondition for rapid local adaptation is diversifying natural selection, but random genetic drift could also be a major driver of this process.

Sea ice meiofauna distribution on local to pan-Arctic scales.

Arctic sea ice provides microhabitats for biota that inhabit the liquid-filled network of brine channels and the ice-water interface. We used meta-analysis of 23 published and unpublished datasets comprising 721 ice cores to synthesize the variability in composition and abundance of sea ice meiofauna at spatial scales ranging from within a single ice core to pan-Arctic and seasonal scales. Two-thirds of meiofauna individuals occurred in the bottom 10 cm of the ice.

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation.

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach.

Allometric trajectories of body and head morphology in three sympatric Arctic charr ( (L.)) morphs.

A study of body and head development in three sympatric reproductively isolated Arctic charr ( (L.)) morphs from a subarctic lake (Skogsfjordvatn, northern Norway) revealed allometric trajectories that resulted in morphological differences. The three morphs were ecologically assigned to a littoral omnivore, a profundal benthivore and a profundal piscivore, and this was confirmed by genetic analyses (microsatellites).

Regulation of gene expression is associated with tolerance of the Arctic copepod to CO-acidified sea water.

Ocean acidification is the increase in seawater CO due to the uptake of atmospheric anthropogenic CO , with the largest changes predicted to occur in the Arctic seas. For some marine organisms, this change in CO , and associated decrease in pH, represents a climate change-related stressor. In this study, we investigated the gene expression patterns of nauplii of the Arctic copepod cultured at low pH levels.

Giant invasive : Friend or foe of plant diversity?

The impact of invasion on diversity varies widely and remains elusive. Despite the considerable attempts to understand mechanisms of biological invasion, it is largely unknown whether some communities' characteristics promote biological invasion, or whether some inherent characteristics of invaders enable them to invade other communities. Our aims were to assess the impact of one of the massive plant invaders of Scandinavia on vascular plant species diversity, disentangle attributes of invasible and noninvasible communities, and evaluate the relationship between invasibility and genetic diversity of a dominant invader.

Prey diversity as a driver of resource partitioning between river-dwelling fish species.

Although food resource partitioning among sympatric species has often been explored in riverine systems, the potential influence of prey diversity on resource partitioning is little known. Using empirical data, we modeled food resource partitioning (assessed as dietary overlap) of coexisting juvenile Atlantic salmon () and alpine bullhead (). Explanatory variables incorporated into the model were fish abundance, benthic prey diversity and abundance, and several dietary metrics to give a total of seventeen potential explanatory variables.

The trade-off between fecundity and egg size in a polymorphic population of Arctic charr ( (L.)) in Skogsfjordvatn, subarctic Norway.

Reproductive traits differ between intralacustrine Arctic charr morphs. Here, we examine three sympatric lacustrine Arctic charr morphs with respect to fecundity, egg size and spawning time/site to assess reproductive investments and trade-offs, and possible fitness consequences. The littoral omnivore morph (LO-morph) utilizes the upper water for feeding and reproduction and spawn early in October.

Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling.

Methane stored in seabed reservoirs such as methane hydrates can reach the atmosphere in the form of bubbles or dissolved in water. Hydrates could destabilize with rising temperature further increasing greenhouse gas emissions in a warming climate. To assess the impact of oceanic emissions from the area west of Svalbard, where methane hydrates are abundant, we used measurements collected with a research aircraft (Facility for Airborne Atmospheric Measurements) and a ship (Helmer Hansen) during the Summer 2014 and for Zeppelin Observatory for the full year.

Community structure affects trophic ontogeny in a predatory fish.

While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e.

Good-bye to tropical alpine plant giants under warmer climates? Loss of range and genetic diversity in .

The main aim of this paper is to address consequences of climate warming on loss of habitat and genetic diversity in the enigmatic tropical alpine giant rosette plants using the Ethiopian endemic as a model. We modeled the habitat suitability of .  and assessed how its range is affected under two climate models and four emission scenarios.

Genetic diversity and connectivity within spp. in the subarctic and Arctic.

Climate changes in the Arctic are predicted to alter distributions of marine species. However, such changes are difficult to quantify because information on present species distribution and the genetic variation within species is lacking or poorly examined. Blue mussels, spp.