Living on the edge: Exploring the role of coastal refugia in the Alexander Archipelago of Alaska

Although islands are of long‐standing interest to biologists, only a handful of studies have investigated the role of climatic history in shaping evolutionary diversification in high‐latitude archipelagos. In this study of the Alexander Archipelago (AA) of Southeast Alaska, we address the impact of glacial cycles on geographic genetic structure for three mammals co‐distributed along the North Pacific Coast. We examined variation in mitochondrial and nuclear loci for long‐tailed voles (Microtus longicaudus), northwestern deermice (Peromyscus keeni), and dusky shrews (Sorex monticola), and then tested hypotheses derived from Species Distribution Models, reconstructions of paleoshorelines, and island area and isolation. In all three species, we identified paleoendemic clades that likely originated in coastal refugia, a finding consistent with other paleoendemic lineages identified in the region such as ermine. Although there is spatial concordance at the regional level for endemism, finer scale spatial and temporal patterns are less clearly defined. Demographic expansion across the region for these distinctive clades is also evident and highlights the dynamic history of Late Quaternary contraction and expansion that characterizes high‐latitude species

Nucleotide sequence and results of test of adaptive evolution in the α-globin gene of octodontoid rodents

The data presented in this article are related to the research article entitled “Molecular adaptive convergence in the α-globin gene in subterranean octodontid rodents” (Tomasco et al., 2017) [1]. This article shows the nucleotide sequences of α-globin subunit gene of hemoglobin of several South American caviomorph rodents, including subterranean and fossorial species. These sequences are deposited in Genbank, with accession numbers ranging from MF169881 to MF169898. Of a total of 429 nucleotides analyzed (143 codons), 100 variable sites and 43 amino acid replacements were reported. In this article we also show the results of TreeSaap (Woolley et al., 2003) [2] and MEME (Murrell et al., 2012) [3], that identified some replacement changes as interesting for future studies of adaptive evolution in this large rodent radiation

Scorched mussels (Brachidontes spp., Bivalvia: Mytilidae) from the tropical and warm-temperate southwestern Atlantic: the role of the Amazon River in their speciation

Antitropicality is a distribution pattern where closely related taxa are separated by an intertropical latitudinal gap. Two potential examples include Brachidontes darwinianus (south eastern Brazil to Uruguay), considered by some authors as a synonym of B. exustus (Gulf of Mexico and the Caribbean), and B. solisianus, distributed along the Brazilian coast with dubious records north of the intertropical zone. Using two nuclear (18S and 28S rDNA) and one mitochondrial gene (mtDNA COI), we aimed to elucidate the phylogeographic and phylogenetic relationships among the scorched mussels present in the warm-temperate region of the southwest Atlantic. We evaluated a divergence process mediated by the tropical zone over alternative phylogeographic hypotheses. Brachidontes solisianus was closely related to B. exustus I, a species with which it exhibits an antitropical distribution. Their divergence time was approximately 2.6 Ma, consistent with the intensification of Amazon River flow. Brachidontes darwinianus, an estuarine species is shown here not to be related to this B. exustus complex. We suspect ancestral forms may have dispersed from the Caribbean to the Atlantic coast via the Trans-Amazonian seaway (Miocene). The third species, B rodriguezii is presumed to have a long history in the region with related fossil forms going back to the Miocene. Although scorched mussels are very similar in appearance, their evolutionary histories are very different, involving major historical contingencies as the formation of the Amazon River, the Panama Isthmus, and the last marine transgressio

Genetic analyses suggest burrow sharing by Río Negro tuco-tucos (Ctenomys rionegrensis)

Genetic analyses of kinship can generate important insights into social structure, particularly forspecies for which direct observations of social relationships are challenging. We used molecular markersto characterize the kin structure of a population of the Río Negro tuco-tuco (Ctenomys rionegrensis), asubterranean species of rodent that is rarely observed above ground. Previous research has revealed thatadults of this species engage in at least periodic episodes of burrow sharing, indicating thatC. rionegrensismaynot be strictly solitary. To explore the kin structure of this species, we used variability at 10 microsatellite locito determine if (1) adults and juveniles captured at the same burrow entrance were parents and o spring and(2) kinship among adults captured together di ered from that among randomly sampled pairs of individuals inour study population. Our analyses revealed that adults and juveniles captured together were not typicallyparents and o spring, suggesting potential mixing of litters among burrow systems. Relatedness among adultscaptured together did not di er from background levels of genetic similarity, providing no evidence thatspatial proximity was associated with kin structure. Collectively, our ndings support the hypothesis thatC. rionegrensisis not strictly solitary but instead engages in burrow sharing by adults and associated litters ofyoung.Los análisis genéticos de parentesco pueden generar importantes ideas sobre la estructura social, particularmente en especies donde las observaciones directas de las relaciones sociales son aún muy discutidas. Utilizamos marcadores moleculares para caracterizar la estructura de parentesco en una población de los tuco-tucos de Río Negro (Ctenomys rionegrensis), una especie de roedores subterráneos que rara vez se observa sobre la super cie. Investigaciones anteriores han revelado que los adultos de esta especie pueden compartir madrigueras, al menos por periodos, indicando que esta especie puede no ser estrictamente solitaria. Para explorar la estructura de parentesco de esta especie utilizamos la variabilidad presente en 10 loci de microsatélites para determinar si (1) adultos y juveniles capturados en la misma madriguera son padres e hijos y (2) el parentesco entre los adultos capturados en las mismas cuevas di ere del de pares de individuos muestreados al azar en la población estudiada. Nuestros análisis revelaron que los adultos y los juveniles capturados juntos típicamente no están emparentados, lo que sugiere una posible mezcla de camadas dentro del sistema de madrigueras. El parentesco entre los adultos capturados juntos, sin embargo, no di rió de los niveles medios de similitud genética, sin proporcionar evidencia de que la proximidad espacial estuviera asociada con la estructura de parentesco. En conjunto, nuestros hallazgos apoyan la hipótesis de que C. rionegrensis no es una especie estrictamente solitaria, sino que existe intercambio de madrigueras entre los adultos y sus camadas asociadas

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

Mitochondrial and microsatellite assessment of population structure of South American sea lion (Otaria flavescens) in the Southwestern Atlantic Ocean

Several major breeding areas have been defined for the South American sea lion (Otaria flavescens) along the Atlantic Ocean including the Uruguayan and Patagonian coasts. Together with a documented and severe reduction in population sizes caused by commercial hunting in the last century, these areas show opposite population trends. While Patagonian populations are recovering since hunting ceased, Uruguayan populations are declining. In this context, population genetic structure and genetic diversity were studied for the first time with both nuclear (microsatellites) and mitochondrial (control region) markers together. Alternative scenarios were found for both markers. While mitochondrial marker showed geographically structured populations, the nuclear loci showed a lack of geographical structure. These opposite patterns in genetic structure could be explained by female phylopatry and high male dispersion. The reduction in population size caused by commercial hunting did not leave a detectable footprint of bottleneck at the genetic level.Fil: Feijoo, Matias. Universidad de la República; UruguayFil: Lessa Gallinal, Enrique Pablo. Universidad de la República; UruguayFil: Loizaga de Castro, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentin