Alaska Science Center
ABOUT THE ALASKA
A Molecular Framework for Predicting Responses of High Latitude Vertebrates to Climate Change
Introduction: Resource managers need to predict the response of species to rapidly changing environmental conditions expected under climate change scenarios, particularly in high latitude ecosystems. Accelerating global climate change in high latitudes is increasingly impacting indigenous people who subsist heavily on native wildlife and plant resources and are at increased risk of exposure to emerging zoonotic diseases. Because parasite and pathogen diversity is generally lower in high latitudes, wildlife species living there are likely to be immunologically naïve to pathogens that accompany colonizing temperate wildlife species expanding from southern regions, as well as from both eastern and western Beringia. Immunological vulnerability, combined with predicted increases in pathogen virulence, may have devastating effects on high latitude species and the indigenous people who depend upon them. Demographic and adaptive response of wildlife species to climate involve genetic changes that leave signatures accessible to rigorous genetic analyses that incorporate coalescence theory and multiple genetic markers applied to both host and parasite species. Determining broad-scale responses to past climate change, across taxonomic groups, will provide a powerful framework for predicting future responses. The goal of this research is to use a molecular approach involving co-distributed species to investigate differential demographic responses of high latitude vertebrates, and associated pathogens, to past climate change.
Research Objectives—Science Impact: This research will synthesize and integrate data collected by multiple laboratories over two decades of ongoing investigations into the population genetics and phylogeography of selected high latitude vertebrate species and their pathogens. The research will use a multiarea/multilocus approach to elucidate the impact of global change upon 1) differentiation in isolation; 2) postglacial expansion of previously isolated species; 3) incidence of hybridization of divergent lineages; 4) timing of contact; and 5) host/parasite history and interactions. We will examine the genetic evidence of transcontinental exchange and late Pleistocene refugia, expansion, and contact between northern terrestrial vertebrate taxa of eastern (Alaska and western Canada) and western (Siberia) Beringia. Augmenting current datasets and synthesizing results, we will focus on a set of specific questions associated with species of western Beringia/Palearctic, eastern Beringia/Nearctic, and the Bering Strait: which wildlife species and associated pathogens have crossed biogeographic/taxonomic boundaries in the past, and for those that have, how easily have they moved between regions? We will search for genetic signatures of demographic change (expansions/contractions) based on past invasions, as well as signals of invasive movements across biomes, incorporating GIS-based landscape and community genetics predictions. These analyses will provide guidance to natural resource managers to 1) predict the response of species and species assemblages to future climate change; 2) identify the most vulnerable, and most resilient species, based on historical and recent responses; and 3) track and respond to distributions and virulence of associated pathogens that shift in response to climate change and associated colonization patterns. This comparative phylogeographic approach can identify large-scale patterns of genetic diversity within and across species, produce key inputs to predictive models, and produce data to target critical information needs articulated by Department of Interior partners and USGS as outlined in the Alaska Executive Climate Roundtable [Sections 6 and 7], contributing to a predictive framework for the likely response of trust species and their zoonotic pathogens to future changes in climate.
Methods Overview: We will test for signals of population expansion in both hosts and associated parasites using coalescence-based models, employing data from multiple genetic markers, including markers associated with immune response, initially in each of 3 avian and 3 mammalian amphi-beringian species occupying 3 – 4 areas in eastern (Alaska) and western (Siberia) Beringia. Sampling of host species will cover areas (n = 30 per population) that will allow tests of the association of population history with geologic history and target potential contact zones and refugia. Broad-scale historical fluctuations will be assayed by comparing sequence data from the control region of the mitochondrial DNA (mtDNA) and among polymorphic single copy nuclear loci, for both host and parasite/pathogen. Within-area population relationships, presence and timing of secondary contact introgression, and recent population fluctuations will be assayed in host species using 8 –15 microsatellite loci. All loci will be assayed via the polymerase chain reaction (PCR).
Personnel: PI: Sandra Talbot, firstname.lastname@example.org, USGS, Alaska Science Center, 4210 University Dr., Anchorage, AK 99508
Collaborators: Joseph A. Cook, Museum of Southwestern Biology, Department of Biology, MSC03 2020, University of New Mexico, Albuquerque, NM 87131-0001
Cooperators: U. S. Fish and Wildlife Service-Region 7, National Park Service, ADFG-State Game Refuges
Milestones/Products: The research will result in publications in scientific journals, and produce non-technical documents related to Beringian species. Specific products will include: 1) a proxy framework for predicting response of high latitude terrestrial vertebrates; 2) peer-reviewed manuscripts documenting single-species and cross-taxa findings, submitted from FY2009 to FY2012; 3) multiple conference presentations in FY2009 to FY2011; 4) Estimates of likely incidence of hybridization resulting from secondary contact of lineages across taxa and incidence of parasite exchange; 5) A database of parasite taxa and genotypes found within the target bird and mammals species; 6) A report establishing demographic response and rate and polarity of transcontinental movement of multiple taxa across Beringia; 7) at least one graduate degree.