The Mitochondrial Genome of Melipona fasciculata (Apidae, Meliponini): Genome Organization and Comparative Analyses, Phylogenetic Implications and Divergence Time Estimations.

The native stingless bee Melipona fasciculata is economically and ecologically important to the Brazilian Northeast, providing a sustainable source of income to family farmers and being considered an effective pollinator in most ecosystems and crops. This study describes, for the first time, the mitogenome of the species and its phylogenetic position. The mitochondrial genome was sequenced using a MiSeq Sequencer (Illumina Inc.

Multifaceted framework for defining conservation units: An example from Atlantic salmon () in Canada.

Conservation units represent important components of intraspecific diversity that can aid in prioritizing and protecting at-risk populations, while also safeguarding unique diversity that can contribute to species resilience. In Canada, identification and assessments of conservation units is done by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). COSEWIC can recognize conservation units below the species level (termed "designatable units"; DUs) if the unit has attributes that make it both discrete and evolutionarily significant.

Fine-scale environmentally associated spatial structure of lumpfish () across the Northwest Atlantic.

Lumpfish, , have historically been harvested throughout Atlantic Canada and are increasingly in demand as a solution to controlling sea lice in Atlantic salmon farms-a process which involves both the domestication and the transfer of lumpfish between geographic regions. At present, little is known regarding population structure and diversity of wild lumpfish in Atlantic Canada, limiting attempts to assess the potential impacts of escaped lumpfish individuals from salmon pens on currently at-risk wild populations. Here, we characterize the spatial population structure and genomic-environmental associations of wild populations of lumpfish throughout the Northwest Atlantic using both 70K SNP array data and whole-genome re-sequencing data (WGS).

Female preference for rare males is maintained by indirect selection in Trinidadian guppies.

When females prefer mates with rare phenotypes, sexual selection can maintain rather than deplete genetic variation. However, there is no consensus on why this widespread and frequently observed preference might evolve and persist. We examine the fitness consequences of female preference for rare male color patterns in a natural population of Trinidadian guppies, using a pedigree that spans 10 generations.

Genomics reveal population structure, evolutionary history, and signatures of selection in the northern bottlenose whale, Hyperoodon ampullatus.

Information on wildlife population structure, demographic history, and adaptations are fundamental to understanding species evolution and informing conservation strategies. To study this ecological context for a cetacean of conservation concern, we conducted the first genomic assessment of the northern bottlenose whale, Hyperoodon ampullatus, using whole-genome resequencing data (n = 37) from five regions across the North Atlantic Ocean. We found a range-wide pattern of isolation-by-distance with a genetic subdivision distinguishing three subgroups: the Scotian Shelf, western North Atlantic, and Jan Mayen regions.

Environmentally associated chromosomal structural variation influences fine-scale population structure of Atlantic Salmon (Salmo salar).

Chromosomal rearrangements (e.g., inversions, fusions, and translocations) have long been associated with environmental variation in wild populations.

Reference genome of lumpfish Cyclopterus lumpus Linnaeus provides evidence of male heterogametic sex determination through the AMH pathway.

Teleosts exhibit extensive diversity of sex determination (SD) systems and mechanisms, providing the opportunity to study the evolution of SD and sex chromosomes. Here we sequenced the genome of the common lumpfish (Cyclopterus lumpus Linnaeus), a species of increasing importance to aquaculture, and identified the SD region and master SD locus using a 70 K single nucleotide polymorphism array and tissue-specific expression data. The chromosome-level assembly identified 25 diploid chromosomes with a total size of 572.

Chromosome level reference of Atlantic halibut Hippoglossus hippoglossus provides insight into the evolution of sexual determination systems.

Changes in the genetic mechanisms that control sexual determination have occurred independently across the tree of life, and with exceptional frequency in teleost fishes. To investigate the genomic changes underlying the evolution of sexual determination, we sequenced a chromosome-level genome, multitissue transcriptomes, and reduced representation population data for the Atlantic halibut (Hippoglossus hippoglossus), which has an XY/XX sex determination mechanism and has recently diverged (0.9-3.

Environmental Change, If Unaccounted, Prevents Detection of Cryptic Evolution in a Wild Population.

AbstractDetecting contemporary evolution requires demonstrating that genetic change has occurred. Mixed effects models allow estimation of quantitative genetic parameters and are widely used to study evolution in wild populations. However, predictions of evolution based on these parameters frequently fail to match observations.

Resistance and resilience of genetic and phenotypic diversity to "black swan" flood events: A retrospective analysis with historical samples of guppies.

Rare extreme "black swan" disturbances can impact ecosystems in many ways, such as destroying habitats, depleting resources, and causing high mortality. In rivers, for instance, exceptional floods that occur infrequently (e.g.

Divergent and linked selection shape patterns of genomic differentiation between European and North American Atlantic salmon (Salmo salar).

As populations diverge many processes can shape genomic patterns of differentiation. Regions of high differentiation can arise due to divergent selection acting on selected loci, genetic hitchhiking of nearby loci, or through repeated selection against deleterious alleles (linked background selection); this divergence may then be further elevated in regions of reduced recombination. Atlantic salmon (Salmo salar) from Europe and North America diverged >600,000 years ago and despite some evidence of secondary contact, the majority of genetic data indicate substantial divergence between lineages.

Multiple decades of stocking has resulted in limited hatchery introgression in wild brook trout () populations of Nova Scotia.

Many populations of freshwater fishes are threatened with losses, and increasingly, the release of hatchery individuals is one strategy being implemented to support wild populations. However, stocking of hatchery individuals may pose long-term threats to wild populations, particularly if genetic interactions occur between wild and hatchery individuals. One highly prized sport fish that has been heavily stocked throughout its range is the brook trout ().

Resolving fine-scale population structure and fishery exploitation using sequenced microsatellites in a northern fish.

The resiliency of populations and species to environmental change is dependent on the maintenance of genetic diversity, and as such, quantifying diversity is central to combating ongoing widespread reductions in biodiversity. With the advent of next-generation sequencing, several methods now exist for resolving fine-scale population structure, but the comparative performance of these methods for genetic assignment has rarely been tested. Here, we evaluate the performance of sequenced microsatellites and a single nucleotide polymorphism (SNP) array to resolve fine-scale population structure in a critically important salmonid in north eastern Canada, Arctic Charr ().

Parasite diversity and ecology in a model species, the guppy () in Trinidad.

The guppy () is a model species in ecology and evolution. Many studies have examined effects of predators on guppy behaviour, reproduction, survival strategies, feeding and other life-history traits, but few have studied variation in their parasite diversity. We surveyed parasites of 18 Trinidadian populations of guppy, to provide insight on the geographical mosaic of parasite variability, which may act as a source of natural selection acting on guppies.

Modular chromosome rearrangements reveal parallel and nonparallel adaptation in a marine fish.

Genomic architecture and standing variation can play a key role in ecological adaptation and contribute to the predictability of evolution. In Atlantic cod (), four large chromosomal rearrangements have been associated with ecological gradients and migratory behavior in regional analyses. However, the degree of parallelism, the extent of independent inheritance, and functional distinctiveness of these rearrangements remain poorly understood.

Evolutionary impacts differ between two exploited populations of northern bottlenose whale ().

Interpretation of conservation status should be informed by an appreciation of genetic diversity, past demography, and overall trends in population size, which contribute to a species' evolutionary potential and resilience to genetic risks. Low genetic diversity can be symptomatic of rapid demographic declines and impose genetic risks to populations, but can also be maintained by natural processes. The northern bottlenose whale has the lowest known mitochondrial diversity of any cetacean and was intensely whaled in the Northwest Atlantic over the last century, but whether exploitation imposed genetic risks that could limit recovery is unknown.

Eco-Evolutionary Feedbacks Predict the Time Course of Rapid Life-History Evolution.

Organisms can change their environment and in doing so change the selection they experience and how they evolve. Population density is one potential mediator of such interactions because high population densities can impact the ecosystem and reduce resource availability. At present, such interactions are best known from theory and laboratory experiments.

A migration-associated supergene reveals loss of biocomplexity in Atlantic cod.

Chromosome structural variation may underpin ecologically important intraspecific diversity by reducing recombination within supergenes containing linked, coadapted alleles. Here, we confirm that an ancient chromosomal rearrangement is strongly associated with migratory phenotype and individual genetic structure in Atlantic cod () across the Northwest Atlantic. We reconstruct trends in effective population size over the last century and reveal declines in effective population size matching onset of industrialized harvest (after 1950).

Evidence for contemporary and historical gene flow between guppy populations in different watersheds, with a test for associations with adaptive traits.

In dendritic river systems, gene flow is expected to occur primarily within watersheds. Yet, rare cross-watershed transfers can also occur, whether mediated by (often historical) geological events or (often contemporary) human activities. We explored these events and their potential evolutionary consequences by analyzing patterns of neutral genetic variation (microsatellites) and adaptive phenotypic variation (male color) in wild guppies () distributed across two watersheds in northern Trinidad.