MIXING IT UP: THE IMPACT OF EPISODIC INTROGRESSION ON THE EVOLUTION OF HIGH-LATITUDE MESOCARNIVORES

At high latitudes, climatic oscillations have triggered repeated episodes of organismal divergence by geographically isolating populations. For terrestrial species, extended isolation in glacial refugia – ice-free regions that enable terrestrial species persistence through glacial maxima – is hypothesized to stimulate allopatric divergence. Alternatively, upon glacial recession, divergent populations expanded from independent glacial refugia and often contacted other diverging populations. In the absence of reproductive isolating mechanisms, this biogeographic process may trigger hybridization and ultimately, gene flow between divergent taxa. My dissertation research aims to understand how these episodic periods of isolation and contact have impacted the evolution of high latitude species. To understand the role of episodic isolation and gene flow on the evolution and diversification of high-latitude species, my dissertation integrates genetic, genomic, and morphometric characters across multiple high-latitude mesocarnivore mammals within the hyper-diverse Mustelidae family. Overall, I identified substantial cryptic diversity in the Arctic and highlight the complementary roles of glacial and interglacial cycles in the evolution and structuring of high latitude biota

Knowing the Biosphere: Documentation, Specimens, Archives, and Names Reveal Environmental Change and Emerging Pathogens

One Health programs and trajectories are now the apparent standard for exploring the occurrence and distribution of emerging pathogens and disease. By definition, One Health has been characterized as a broadly inclusive, collaborative, and transdisciplinary approach with connectivity across local to global scales, which integrates the medical and veterinary community to recognize health outcomes emerging at the environmental nexus for people, animals, plants, and their shared landscapes. One Health has been an incomplete model, conceptually and operationally, focused on reactive and response-based foundations, to limit the impact of emerging pathogens and emerging infectious diseases and, as such, lacks a powerful proactive capacity. A proactive, predictive One Health is necessary, emanating in part from geographically/taxonomically broad and temporally deep biological collections of pathogen-host assemblages. The DAMA protocol (Document, Assess, Monitor, Act), the operational extension of the Stockholm paradigm (SP), accomplishes this task by encompassing holistic and strategic biological sampling of reservoir host assemblages and pathogens at environmental interfaces and more extensively through resurveys, with development of informatics resources digitally linked to physical specimens held in publicly accessible museum biorepositories. Archives of specimens are the foundations for accumulating interrelated archives of information (the baselines against which change can be identified and tracked), with collections serving as fundamental resources for biodiversity informatics under the conceptual evolutionary and ecological umbrella of the SP. A cultural and conceptual transformation is essential among the diverse practitioners in the One Health community, one that recognizes the necessity of placing pathogens in an evolutionary, ecological, and environmental context by integrating specimens and associated informatics into an infrastructure and networks for actionable information. As a community, it is essential to abandon response-based business as usual while looking forward toward proactive transboundary approaches that maximize our conceptual and taxonomic view of diversity across interconnected planetary scales that influence the complexity of pathogen-host interfaces. Evolution, where the past always influences the present and the future, defines our trajectory, as the need for sustained archives that describe the biosphere becomes more acute with each passing day

Limited Evidence for Parallel Evolution Among Desert-Adapted Peromyscus Deer Mice

Warming climate and increasing desertification urge the identification of genes involved in heat and dehydration tolerance to better inform and target biodiversity conservation efforts. Comparisons among extant desert-adapted species can highlight parallel or convergent patterns of genome evolution through the identification of shared signatures of selection. We generate a chromosome-level genome assembly for the canyon mouse (Peromyscus crinitus) and test for a signature of parallel evolution by comparing signatures of selective sweeps across population-level genomic resequencing data from another congeneric desert specialist (Peromyscus eremicus) and a widely distributed habitat generalist (Peromyscus maniculatus), that may be locally adapted to arid conditions. We identify few shared candidate loci involved in desert adaptation and do not find support for a shared pattern of parallel evolution. Instead, we hypothesize divergent molecular mechanisms of desert adaptation among deer mice, potentially tied to species-specific historical demography, which may limit or enhance adaptation. We identify a number of candidate loci experiencing selective sweeps in the P. crinitus genome that are implicated in osmoregulation (Trypsin, Prostasin) and metabolic tuning (Kallikrein, eIF2-alpha kinase GCN2, APPL1/2), which may be important for accommodating hot and dry environmental conditions

Leveraging natural history biorepositories as a global, decentralized, pathogen surveillance network

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic reveals a major gap in global biosecurity infrastructure: a lack of publicly available biological samples representative across space, time, and taxonomic diversity. The shortfall, in this case for vertebrates, prevents accurate and rapid identification and monitoring of emerging pathogens and their reservoir host(s) and precludes extended investigation of ecological, evolutionary, and environmental associations that lead to human infection or spillover. Natural history museum biorepositories form the backbone of a critically needed, decentralized, global network for zoonotic pathogen surveillance, yet this infrastructure remains marginally developed, underutilized, underfunded, and disconnected from public health initiatives. Proactive detection and mitigation for emerging infectious diseases (EIDs) requires expanded biodiversity infrastructure and training (particularly in biodiverse and lower income countries) and new communication pipelines that connect biorepositories and biomedical communities. To this end, we highlight a novel adaptation of Project ECHO’s virtual community of practice model: Museums and Emerging Pathogens in the Americas (MEPA). MEPA is a virtual network aimed at fostering communication, coordination, and collaborative problem-solving among pathogen researchers, public health officials, and biorepositories in the Americas. MEPA now acts as a model of effective international, interdisciplinary collaboration that can and should be replicated in other biodiversity hotspots. We encourage deposition of wildlife specimens and associated data with public biorepositories, regardless of original collection purpose, and urge biorepositories to embrace new specimen sources, types, and uses to maximize strategic growth and utility for EID research. Taxonomically, geographically, and temporally deep biorepository archives serve as the foundation of a proactive and increasingly predictive approach to zoonotic spillover, risk assessment, and threat mitigation

Data from: Whole-genome analysis of Mustela erminea finds that pulsed hybridization impacts evolution at high-latitudes

At high-latitude, climatic shifts hypothetically drove episodes of divergence during isolation in glacial refugia, or ice-free pockets of land that enabled terrestrial species persistence. Upon glacial recession, populations can expand and often come into contact, resulting in admixture between previously isolated groups. To understand how recurrent periods of isolation and contact have impacted evolution at high latitudes, we investigated introgression in the stoat (Mustela erminea), a Holarctic mammalian carnivore, using whole-genome sequences. We identify two temporally isolated introgression events coincident with large-scale climatic shifts: contemporary introgression in a mainland contact zone and ancient contact ~ 200 km south along North America’s North Pacific Coast. Repeated episodes of gene flow highlight the central role of cyclic climates in structuring high-latitude diversity, through refugial divergence and subsequent introgressive hybridization. Introgression followed by allopatry (e.g., insularization) may contribute to expedited divergence of island taxa experiencing substantial glacial flux

Tar ball of genome .fq files of Mustela erminea (N=10)

Tar ball of genome ,fq files of Mustela erminea, representing specimens from Museum of Southwestern Biology (MSB) with catalog number: 152905 (ME01), 221783 (ME02), 199855 (ME03), 43333 (ME04), 145234 (ME05), 148962 (ME06), 149365 (ME07), 144524 (ME08), 215111 (ME09), 248153 (ME10)

First Record of the Holarctic Least Shrew (Sorex minutissimus) and Associated Helminths from Canada: New Light on Northern Pleistocene Refugia

We report the first Canadian record of the Holarctic least shrew (Sorex minutissimus Zimmermann, 1780) and associated helminth worms, collected along the Dempster Highway in central Yukon in 2014. We identify the specimen based on morphological characters, characterize the habitat, report other mammals and helminth species associated with this specimen, and use mitochondrial DNA sequences to place the specimen within a phylogenetic context and address Pleistocene refugial hypotheses. Although long considered an Asian endemic, the diminutive least shrew was first reported from Alaska in 1994. Our new record for Canada indicates that the species may occur at least as far east as the MacKenzie River and DNA variation suggests this species persisted only in the Beringian refugium in North America during the Last Glacial Maximum. The discovery of a new mammal and associated parasites for Canada points to the urgent need for more detailed information on high-latitude biotas in North America, data that are best obtained through museum-based field surveys, particularly for small, cryptic species.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Two Decades of Wildlife Pathogen Surveillance: Case Study of <i>Choclo orthohantavirus</i> and Its Wild Reservoir <i>Oligoryzomys costaricensis</i>

The Costa Rican pygmy rice rat (Oligoryzomys costaricensis) is the primary reservoir of Choclo orthohantavirus (CHOV), the causal agent of hantavirus disease, pulmonary syndrome, and fever in humans in Panama. Since the emergence of CHOV in early 2000, we have systematically sampled and archived rodents from >150 sites across Panama to establish a baseline understanding of the host and virus, producing a permanent archive of holistic specimens that we are now probing in greater detail. We summarize these collections and explore preliminary habitat/virus associations to guide future wildlife surveillance and public health efforts related to CHOV and other zoonotic pathogens. Host sequences of the mitochondrial cytochrome b gene form a single monophyletic clade in Panama, despite wide distribution across Panama. Seropositive samples were concentrated in the central region of western Panama, consistent with the ecology of this agricultural commensal and the higher incidence of CHOV in humans in that region. Hantavirus seroprevalence in the pygmy rice rat was >15% overall, with the highest prevalence in agricultural areas (21%) and the lowest prevalence in shrublands (11%). Host–pathogen distribution, transmission dynamics, genomic evolution, and habitat affinities can be derived from the preserved samples, which include frozen tissues, and now provide a foundation for expanded investigations of orthohantaviruses in Panama

Build international biorepository capacity

In their Perspective “Rigorous wildlife disease surveillance” (10 July, p. 145), M. Watsa et al. underscore the value of One Health approaches to stimulate integration across currently siloed efforts in zoonotic research and mitigation. To achieve comprehensive decentralized pathogen surveillance, there is an urgent need to develop environmental and biodiversity infrastructure in biodiverse countries experiencing high rates of habitat conversion, wildlife trafficking, and human-wildlife interactions