7 research outputs found

    Runs of homozygosity in killer whale genomes provide a global record of demographic histories

    Get PDF
    Runs of homozygosity (ROH) occur when offspring inherit haplotypes that are identical by descent from each parent. Length distributions of ROH are informative about population history; specifically, the probability of inbreeding mediated by mating system and/or population demography. Here, we investigated whether variation in killer whale (Orcinus orca) demographic history is reflected in genome-wide heterozygosity and ROH length distributions, using a global data set of 26 genomes representative of geographic and ecotypic variation in this species, and two F1 admixed individuals with Pacific-Atlantic parentage. We first reconstructed demographic history for each population as changes in effective population size through time using the pairwise sequential Markovian coalescent (PSMC) method. We found a subset of populations declined in effective population size during the Late Pleistocene, while others had more stable demography. Genomes inferred to have undergone ancestral declines in effective population size, were autozygous at hundreds of short ROH (1.5 Mb) were found in low latitude populations, and populations of known conservation concern. These include a Scottish killer whale, for which 37.8% of the autosomes were comprised of ROH >1.5 Mb in length. The fate of this population, in which only two adult males have been sighted in the past five years, and zero fecundity over the last two decades, may be inextricably linked to its demographic history and consequential inbreeding depression

    “Type D” killer whale genomes reveal long-term small population size and low genetic diversity

    No full text
    Genome sequences can reveal the extent of inbreeding in small populations. Here, we present the first genomic characterization of type D killer whales, a distinctive eco/morphotype with a circumpolar, subantarctic distribution. Effective population size is the lowest estimated from any killer whale genome and indicates a severe population bottleneck. Consequently, type D genomes show among the highest level of inbreeding reported for any mammalian species (FROH ≥ 0.65). Detected recombination cross-over events of different haplotypes are up to an order of magnitude rarer than in other killer whale genomes studied to date. Comparison of genomic data from a museum specimen of a type D killer whale that stranded in New Zealand in 1955, with 3 modern genomes from the Cape Horn area, reveals high covariance and identity-by-state of alleles, suggesting these genomic characteristics and demographic history are shared among geographically dispersed social groups within this morphotype. Limitations to the insights gained in this study stem from the nonindependence of the 3 closely related modern genomes, the recent coalescence time of most variation within the genomes, and the nonequilibrium population history which violates the assumptions of many model-based methods. Long-range linkage disequilibrium and extensive runs of homozygosity found in type D genomes provide the potential basis for both the distinctive morphology, and the coupling of genetic barriers to gene flow with other killer whale populations

    BFA 2017-2018 Senior Show Catalog

    No full text
    Exhibition catalog for December 2017 and Spring 2018 Bachelor of Fine Arts (B.F.A.) thesis exhibitions in the Earl & Virginia Green Art Gallery at Biola University. In Particular - photography - Emily Hayashida; Cross Over Move Into - photography - Marika Adamopoulos; In progress - photography - Shelby Montelongo; have a dream and have a job and - photography - Jordan Wilson; One Thing at a Time Frankie - drawing & painting - Kat Ashdown; How\u27s Your Family? - Interdisciplinary - Janna Christian; Transept - drawing & painting - Rebecca Mott; Mr. Pareidolia - Interdisciplinary - Delanie Eng; Mojo - Interdisciplinary - Trevor Lunde; Gas Bill - drawing & painting - Michelle Parada; Exactly Not It - Interdisciplinary - Amanda Delaplane; I’ll Be There for You Sometimes - Interdisciplinary - Brianna Eng; Recovered - drawing & painting - Laura Webster; Embody - drawing & painting - Wesleigh Byrd; More Accidentally on Purpose - Interdisciplinary - Lisa Tixier; The Darkness He Called Night - drawing & painting - Kaila Williams; Invitation - sculpture - Kibbi Peng; Dynamo Genesis - design - Tony Walsh; Ambient - design - Chad Swanson; December Eleventh - Interdisciplinary - Jeddiah Angkasa; Side Eye - design - Sean Leone;https://digitalcommons.biola.edu/exhibit-catalogs/1000/thumbnail.jp

    Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment

    Get PDF
    We reviewed compliance monitoring requirements in the European Union, the United States, and the Oslo-Paris Convention for the protection of the marine environment of the North-East Atlantic, and evaluated if these are met by passive sampling methods for nonpolar compounds. The strengths and shortcomings of passive sampling are assessed for water, sediments, and biota. Passive water sampling is a suitable technique for measuring concentrations of freely dissolved compounds. This method yields results that are incompatible with the EU's quality standard definition in terms of total concentrations in water, but this definition has little scientific basis. Insufficient quality control is a present weakness of passive sampling in water. Laboratory performance studies and the development of standardized methods are needed to improve data quality and to encourage the use of passive sampling by commercial laboratories and monitoring agencies. Successful prediction of bioaccumulation based on passive sampling is well documented for organisms at the lower trophic levels, but requires more research for higher levels. Despite the existence of several knowledge gaps, passive sampling presently is the best available technology for chemical monitoring of nonpolar organic compounds. Key issues to be addressed by scientists and environmental managers are outlined
    corecore