Global adaptation occurs when all populations of a species undergo selection toward a common optimum. This can occur by a hard selective sweep with the emergence of a new globally advantageous allele that spreads throughout a species' natural range until reaching fixation. This evolutionary process leaves a temporary trace in the region affected, which is detectable using population genomic methods.
View Article and Find Full Text PDFLocally adapted traits can exhibit a wide range of genetic architectures, from pronounced divergence at a few loci to small frequency divergence at many loci. The type of architecture that evolves depends strongly on the migration rate, as weakly selected loci experience swamping and do not make lasting contributions to divergence. Simulations from previous studies showed that even when mutations are strongly selected and should resist migration swamping, the architecture of adaptation can collapse and become transient at high mutation rates.
View Article and Find Full Text PDFClosely related species often use the same genes to adapt to similar environments. However, we know little about why such genes possess increased adaptive potential and whether this is conserved across deeper evolutionary lineages. Adaptation to climate presents a natural laboratory to test these ideas, as even distantly related species must contend with similar stresses.
View Article and Find Full Text PDFContact zones between divergent forms within a species provide insight into the role of gene flow in adaptation and speciation. Previous work has focused on contact zones involving only two divergent forms, but in nature, many more than two populations may overlap simultaneously and experience gene flow. Patterns of introgression in wild populations are, therefore, likely much more complicated than is often assumed.
View Article and Find Full Text PDFThe ability to navigate effectively in a rich and complex world is crucial for the survival of all animals. Specialist neural structures have evolved that are implicated in facilitating this ability, one such structure being the ring attractor network. In this study, we model a trio of Spiking Neural Network (SNN) ring attractors as part of a bio-inspired navigation system to maintain an internal estimate of planar translation of an artificial agent.
View Article and Find Full Text PDFObjective: The ongoing complexity of general surgery training has led to an increased focus on ensuring the competence of graduating residents. Entrustable professional activities (EPAs) are units of professional practice that provide an assessment framework to drive competency-based education. The American Board of Surgery convened a group from the American College of Surgeons, Accreditation Council for Graduate Medical Education (ACGME) Surgery Review Committee, and Association of Program Directors in Surgery to develop and implement EPAs in a pilot group of residency programs across the country.
View Article and Find Full Text PDFObjective: To assess the educational of value of teaching assistant (TA) cases from the perspectives of attending, chief resident, and junior resident. We hypothesized the greatest educational value of TA cases would be for chief residents more so than other team members.
Design: A prospective survey was designed and collected for TA cases separately from attendings, chief residents, and junior residents to assess operative details and educational value.
Blue mussels from the genus are an abundant component of the benthic community, found in the high latitude habitats. These foundation species are relevant to the aquaculture industry, with over 2 million tonnes produced globally each year. Mussels withstand a wide range of environmental conditions and species from the complex readily hybridize in regions where their distributions overlap.
View Article and Find Full Text PDFGenotype-environment association (GEA) studies have the potential to identify the genetic basis of local adaptation in natural populations. Specifically, GEA approaches look for a correlation between allele frequencies and putatively selective features of the environment. Genetic markers with extreme evidence of correlation with the environment are presumed to be tagging the location of alleles that contribute to local adaptation.
View Article and Find Full Text PDFBackground: Poor personal financial health has been linked to key components of health including burnout, substance abuse, and worsening personal relationships. Understanding the state of resident financial health is key to improving their overall well-being.
Study Design: A secondary analysis of a survey of New England general surgery residents was performed to understand their financial well-being.
Speciation is a continuous and complex process shaped by the interaction of numerous evolutionary forces. Despite the continuous nature of the speciation process, the implementation of conservation policies relies on the delimitation of species and evolutionary significant units (ESUs). Puffinus shearwaters are globally distributed and threatened pelagic seabirds.
View Article and Find Full Text PDFBackground: Exploring the lived experiences of surgeons is necessary to understand the changing culture of surgery and the unique challenges of being a woman in surgery. Surgeons have significant experiences and observations best discovered through qualitative study. The purpose of this study is to identify the similarities and differences between the experiences of men and women surgeons after initiation of mandatory microaggression training.
View Article and Find Full Text PDFBackground: Surgical culture has shifted to recognize the importance of resident well-being. This is the first study to longitudinally track regional surgical resident well-being over 5 years.
Study Design: An anonymous cross-sectional, multi-institutional survey of New England general surgery residents using novel and published instruments to create three domains: health maintenance, burnout, and work environment.
Although rapid phenotypic evolution has been documented often, the genomic basis of rapid adaptation to natural environments is largely unknown in multicellular organisms. Population genomic studies of experimental populations of Trinidadian guppies () provide a unique opportunity to study this phenomenon. Guppy populations that were transplanted from high-predation (HP) to low-predation (LP) environments have been shown to evolve toward the phenotypes of naturally colonized LP populations in as few as eight generations.
View Article and Find Full Text PDFMale colour patterns of the Trinidadian guppy (Poecilia reticulata) are typified by extreme variation governed by both natural and sexual selection. Since guppy colour patterns are often inherited faithfully from fathers to sons, it has been hypothesised that many of the colour trait genes must be physically linked to sex determining loci as a 'supergene' on the sex chromosome. Here, we phenotype and genotype four guppy 'Iso-Y lines', where colour was inherited along the patriline for 40 generations.
View Article and Find Full Text PDFThe genetic basis of traits shapes and constrains how adaptation proceeds in nature; rapid adaptation can proceed using stores of polygenic standing genetic variation or hard selective sweeps, and increasing polygenicity fuels genetic redundancy, reducing gene re-use (genetic convergence). Guppy life history traits evolve rapidly and convergently among natural high- and low-predation environments in northern Trinidad. This system has been studied extensively at the phenotypic level, but little is known about the underlying genetic architecture.
View Article and Find Full Text PDFStudies of convergence in wild populations have been instrumental in understanding adaptation by providing strong evidence for natural selection. At the genetic level, we are beginning to appreciate that the re-use of the same genes in adaptation occurs through different mechanisms and can be constrained by underlying trait architectures and demographic characteristics of natural populations. Here, we explore these processes in naturally adapted high- (HP) and low-predation (LP) populations of the Trinidadian guppy, Poecilia reticulata.
View Article and Find Full Text PDFTheory predicts that the sexes can achieve greater fitness if loci with sexually antagonistic polymorphisms become linked to the sex determining loci, and this can favor the spread of reduced recombination around sex determining regions. Given that sex-linked regions are frequently repetitive and highly heterozygous, few complete Y chromosome assemblies are available to test these ideas. The guppy system (Poecilia reticulata) has long been invoked as an example of sex chromosome formation resulting from sexual conflict.
View Article and Find Full Text PDFObjective: The interview process for applying to general surgery residency is burdened by a high volume of applicants, resulting in unprofessional behavior by both applicants and programs. Sharing more information regarding interview scheduling with applicants may limit fourth year medical student educational disruptions, minimized late cancellations to interview, and improve overall satisfaction with the process. Thus, we set out to determine what information is currently available to applicants.
View Article and Find Full Text PDFObjective: Undergraduate and graduate education research has stratified study strategies from low-utility to high-utility with respect to durable learning. The purpose of this study was to determine the prevalence of these evidence-based learning strategies among surgery residents in preparation for the American Board of Surgery In-Training Examination (ABSITE).
Design: A 23-item survey was administered during individual interviews.
Seasonal disease and parasitic infection are common across organisms, including humans, and there is increasing evidence for intrinsic seasonal variation in immune systems. Changes are orchestrated through organisms' physiological clocks using cues such as day length. Ample research in diverse taxa has demonstrated multiple immune responses are modulated by photoperiod, but to date, there have been few experimental demonstrations that photoperiod cues alter susceptibility to infection.
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