scholarly journals Low Persistence of Genetic Rescue Across Generations in the Arctic Fox (Vulpes lagopus)

2021 ◽  
Author(s):  
Anna Lotsander ◽  
Malin Hasselgren ◽  
Malin Larm ◽  
Johan Wallén ◽  
Anders Angerbjörn ◽  
...  
Keyword(s):  
Time Perspective ◽  
Chromosome Analysis ◽  
Small Population ◽  
The Arctic ◽  
Vulpes Lagopus ◽  
Long Term Effects ◽  
Genetic Rescue ◽  
Isolated Populations ◽  
Individual Fitness

Abstract Genetic rescue can facilitate the recovery of small and isolated populations suffering from inbreeding depression. Long-term effects are however complex, and examples spanning over multiple generations under natural conditions are scarce. The aim of this study was to test for long-term effects of natural genetic rescue in a small population of Scandinavian Arctic foxes (Vulpes lagopus). By combining a genetically verified pedigree covering almost 20 years with a long-term dataset on individual fitness (n = 837 individuals), we found no evidence for elevated fitness in immigrant F2 and F3 compared to native inbred foxes. Population inbreeding levels showed a fluctuating increasing trend and emergence of inbreeding within immigrant lineages shortly after immigration. Between 0–5 and 6–9 years post immigration, the average number of breeding adults decreased by almost 22% and the average proportion of immigrant ancestry rose from 14% to 27%. Y chromosome analysis revealed that 2 out of 3 native male lineages were lost from the gene pool, but all founders represented at the time of immigration were still contributing to the population at the end of the study period through female descendants. The results highlight the complexity of genetic rescue and suggest that beneficial effects can be brief. Continuous gene flow may be needed for small and threatened populations to recover and persist in a longer time perspective.

scholarly journals Genetic rescue in an inbred Arctic fox ( Vulpes lagopus ) population

2018 ◽  
Vol 285 (1875) ◽  
pp. 20172814 ◽  
Author(s):  
Malin Hasselgren ◽  
Anders Angerbjörn ◽  
Nina E. Eide ◽  
Rasmus Erlandsson ◽  
Øystein Flagstad ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
First Generation ◽  
Small Population ◽  
Arctic Fox ◽  
Vulpes Lagopus ◽  
Genetic Rescue ◽  
Individual Fitness ◽  
Fitness Traits ◽  
Population Average

Isolation of small populations can reduce fitness through inbreeding depression and impede population growth. Outcrossing with only a few unrelated individuals can increase demographic and genetic viability substantially, but few studies have documented such genetic rescue in natural mammal populations. We investigate the effects of immigration in a subpopulation of the endangered Scandinavian arctic fox ( Vulpes lagopus ), founded by six individuals and isolated for 9 years at an extremely small population size. Based on a long-term pedigree (105 litters, 543 individuals) combined with individual fitness traits, we found evidence for genetic rescue. Natural immigration and gene flow of three outbred males in 2010 resulted in a reduction in population average inbreeding coefficient ( f ), from 0.14 to 0.08 within 5 years. Genetic rescue was further supported by 1.9 times higher juvenile survival and 1.3 times higher breeding success in immigrant first-generation offspring compared with inbred offspring. Five years after immigration, the population had more than doubled in size and allelic richness increased by 41%. This is one of few studies that has documented genetic rescue in a natural mammal population suffering from inbreeding depression and contributes to a growing body of data demonstrating the vital connection between genetics and individual fitness.

The Long-Term Effects of Living in a Shared and Continuous Traumatic Reality: The Case of Israeli Families on the Border With Gaza

2021 ◽  
pp. 152483802110634
Author(s):  
Orit Nuttman-Shwartz
Keyword(s):  
Political Violence ◽  
Traumatic Stress ◽  
Family Intervention ◽  
Small Population ◽  
Long Term Effects ◽  
Family Dynamic ◽  
Parents And Children ◽  
Trauma Transmission ◽  
Persistent Violence

This article presents a literature review of the concept of intergenerational transmission of traumatic stress among a specific population of Israeli parents and children living near the Israeli/Gaza border, an area that can essentially be viewed as a laboratory of shared, continuous, and stressful reality resulting from ongoing political violence. The Google Scholar database was used to search only for peer-reviewed articles written in English and published between 2002 and 2020, and the particular focus of the study was Israeli families living in the “Gaza envelope”: communities that have been on the receiving end of rockets and mortars from Gaza for the past 20 years. The review was based on 35 articles and sheds light on the existence of studies using a variety of perspectives (e.g., psychological, biopsychosocial, and behavioral). Findings demonstrate the effects of continuous stress situations on the family dynamic, even before birth, among this small population. In addition, they show that to understand the unique process of intergenerational trauma transmission in a shared continuous traumatic reality, it is important to adopt a comprehensive perspective so as to understand the reciprocal, long-lasting, and transgenerational effects of being exposed to traumatic stress. This perspective can be used as a basis for developing family intervention strategies that are appropriate for preventing stress outcomes that derive from living in the context of persistent violence.

scholarly journals Nest-site competition and killing by invasive parakeets cause the decline of a threatened bat population

2018 ◽  
Vol 5 (5) ◽  
pp. 172477 ◽  
Author(s):  
Dailos Hernández-Brito ◽  
Martina Carrete ◽  
Carlos Ibáñez ◽  
Javier Juste ◽  
José L. Tella
Keyword(s):  
Native Species ◽  
Population Decline ◽  
Urban Environments ◽  
Strong Impact ◽  
Long Term Effects ◽  
Individual Fitness ◽  
Tree Cavities ◽  
Negative Impacts ◽  
Site Competition

The identification of effects of invasive species is challenging owing to their multifaceted impacts on native biota. Negative impacts are most often reflected in individual fitness rather than in population dynamics of native species and are less expected in low-biodiversity habitats, such as urban environments. We report the long-term effects of invasive rose-ringed parakeets on the largest known population of a threatened bat species, the greater noctule, located in an urban park. Both species share preferences for the same tree cavities for breeding. While the number of parakeet nests increased by a factor of 20 in 14 years, the number of trees occupied by noctules declined by 81%. Parakeets occupied most cavities previously used by noctules, and spatial analyses showed that noctules tried to avoid cavities close to parakeets. Parakeets were highly aggressive towards noctules, trying to occupy their cavities, often resulting in noctule death. This led to a dramatic population decline, but also an unusual aggregation of the occupied trees, probably disrupting the complex social behaviour of this bat species. These results indicate a strong impact through site displacement and killing of competitors, and highlight the need for long-term research to identify unexpected impacts that would otherwise be overlooked.

scholarly journals Post-fire vegetation succession in the Siberian subarctic tundra over 45 years

2019 ◽  
Author(s):  
Ramona J. Heim ◽  
Anna Bucharova ◽  
Leya Brodt ◽  
Johannes Kamp ◽  
Daniel Rieker ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Vegetation Cover ◽  
The Arctic ◽  
Vegetation Recovery ◽  
Long Term Effects ◽  
Forest Tundra ◽  
Permafrost Thaw ◽  
Legacy Effect ◽  
Thaw Depth

AbstractWildfires are relatively rare in subarctic tundra ecosystems, but they can strongly change ecosystem properties. Short-term fire effects on subarctic tundra vegetation are well documented, but long-term vegetation recovery has been studied less. The frequency of tundra fires will increase with climate warming. Understanding the long-term effects of fire is necessary to predict future ecosystem changes.We used a space-for-time approach to assess vegetation recovery after fire over more than four decades. We studied soil and vegetation patterns on three large fire scars (>44, 28 and 12 years old) in dry, lichen-dominated forest tundra in Western Siberia. On 60 plots, we determined soil temperature and permafrost thaw depth, sampled vegetation and measured plant functional traits. We assessed trends in NDVI to support the field-based results on vegetation recovery.Soil temperature, permafrost thaw depth and total vegetation cover had recovered to pre-fire levels after >44 years, as well as total vegetation cover. In contrast, after >44 years, functional groups had not recovered to the pre-fire state. Burnt areas had lower lichen and higher bryophyte and shrub cover. The dominating shrub species, Betula nana, exhibited a higher vitality (higher specific leaf area and plant height) on burnt compared with control plots, suggesting a fire legacy effect in shrub growth. Our results confirm patterns of shrub encroachment after fire that were detected before in other parts of the Arctic and Subarctic. In the so far poorly studied Western Siberian forest tundra we demonstrate for the first time, long-term fire-legacies on the functional composition of relatively dry shrub- and lichen-dominated vegetation.

scholarly journals Long-term effects of snowmelt timing and climate warming on phenology, growth and reproductive effort of arctic tundra plant species

2021 ◽  
Author(s):  
Esther R. Frei ◽  
Greg H.R. Henry
Keyword(s):  
Plant Species ◽  
Reproductive Effort ◽  
High Arctic ◽  
Snow Accumulation ◽  
The Arctic ◽  
Plant Responses ◽  
Long Term Effects ◽  
Passive Warming ◽  
Species Specific

Arctic regions are particularly affected by rapidly rising temperatures and altered snow regimes. Snowmelt timing depends on spring temperatures and winter snow accumulation. Scenarios for the Arctic include both decreases and increases in snow accumulation. Predictions of future snowmelt timing are thus difficult and experimental evidence for ecological consequences is scarce. In 1995, a long-term factorial experiment was set up in a High Arctic evergreen shrub heath community on Ellesmere Island, Canada. We investigated how snow removal, snow addition and passive warming affected phenology, growth and reproductive effort of the four common tundra plant species <i>Cassiope tetragona</i>, <i>Dryas integrifolia</i>, <i>Luzula arctica</i> and <i>Papaver radicatum</i>. Timing of flowering and seed maturation as well as flower production were more strongly influenced by the combined effects of snowmelt timing and warming in the two shrub species than in the two herbaceous species. Warming effects persisted over the course of the growing season and resulted in increased shrub growth. Moreover, the long-term trend of increasing growth in two species suggests that ambient warming promotes tundra plant growth. Our results confirm the importance of complex interactions between temperature and snowmelt timing in driving species-specific plant responses to climate change in the Arctic.

scholarly journals Behavioral Response Study on Seismic Airgun and Vessel Exposures in Narwhals

2021 ◽  
Vol 8 ◽  
Author(s):  
Mads Peter Heide-Jørgensen ◽  
Susanna B. Blackwell ◽  
Outi M. Tervo ◽  
Adeline L. Samson ◽  
Eva Garde ◽  
...  
Keyword(s):  
Noise Exposure ◽  
Anthropogenic Activities ◽  
Travel Speed ◽  
The Arctic ◽  
Line Of Sight ◽  
Long Term Effects ◽  
Sound Exposure ◽  
Ice Coverage ◽  
Exposure Levels

One of the last pristine marine soundscapes, the Arctic, is exposed to increasing anthropogenic activities due to climate-induced decrease in sea ice coverage. In this study, we combined movement and behavioral data from animal-borne tags in a controlled sound exposure study to describe the reactions of narwhals, Monodon monoceros, to airgun pulses and ship noise. Sixteen narwhals were live captured and instrumented with satellite tags and Acousonde acoustic-behavioral recorders, and 11 of them were exposed to airgun pulses and vessel sounds. The sound exposure levels (SELs) of pulses from a small airgun (3.4 L) used in 2017 and a larger one (17.0 L) used in 2018 were measured using drifting recorders. The experiment was divided into trials with airgun and ship-noise exposure, intertrials with only ship-noise, and pre- and postexposure periods. Both trials and intertrials lasted ∼4 h on average per individual. Depending on the location of the whales, the number of separate exposures ranged between one and eight trials or intertrials. Received pulse SELs dropped below 130 dB re 1 μPa2 s by 2.5 km for the small airgun and 4–9 km for the larger airgun, and background noise levels were reached at distances of ∼3 and 8–10.5 km, respectively, for the small and big airguns. Avoidance reactions of the whales could be detected at distances &gt;5 km in 2017 and &gt;11 km in 2018 when in line of sight of the seismic vessel. Meanwhile, a ∼30% increase in horizontal travel speed could be detected up to 2 h before the seismic vessel was in line of sight. Applying line of sight as the criterion for exposure thus excludes some potential pre-response effects, and our estimates of effects must therefore be considered conservative. The whales reacted by changing their swimming speed and direction at distances between 5 and 24 km depending on topographical surroundings where the exposure occurred. The propensity of the whales to move towards the shore increased with increasing exposure (i.e., shorter distance to vessels) and was highest with the large airgun used in 2018, where the whales moved towards the shore at distances of 10–15 km. No long-term effects of the response study could be detected.

scholarly journals Genomic signatures of inbreeding and genetic load in a threatened rattlesnake

2021 ◽  
Author(s):  
Alexander Ochoa ◽  
H. Lisle Gibbs
Keyword(s):  
Threatened Species ◽  
Empirical Studies ◽  
Genetic Load ◽  
Population History ◽  
Deleterious Mutations ◽  
Genetic Rescue ◽  
Isolated Populations ◽  
Genome Wide ◽  
The Impact

Theory predicts that threatened species living in small populations will experience high levels of inbreeding that will increase their negative genetic load but recent work suggests that the impact of load may be minimized by purging resulting from long term population bottlenecks. Empirical studies that examine this idea using genome-wide estimates of inbreeding and genetic load in threatened species are limited. Here we use genome resequencing data to compare levels of inbreeding, levels of genetic load and population history in threatened Eastern massasauga rattlesnakes (Sistrurus catenatus) which exist in small isolated populations and closely-related yet outbred Western massasauga rattlesnakes (S. tergeminus). In terms of inbreeding, S. catenatus genomes had a greater number of ROHs of varying sizes indicating sustained inbreeding through repeated bottlenecks when compared to S. tergeminus. At the species level, outbred S. tergeminus had higher genome-wide levels of genetic load in the form of greater numbers of derived deleterious mutations compared to S. catenatus presumably due to long-term purging of deleterious mutations in S. catenatus. In contrast, mutations that escaped the “drift sieve” and were polymorphic within S. catenatus populations were more abundant and more often found in homozygote genotypes than in S. tergeminus suggesting a reduced efficiency of purifying selection in smaller S. catenatus populations. Our results support an emerging idea that the historical demography of a threatened species has a significant impact on the type of genetic load present which impacts implementation of conservation actions such as genetic rescue.

scholarly journals Mountain lion genomes provide insights into genetic rescue of inbred populations

2018 ◽  
Author(s):  
Nedda F. Saremi ◽  
Megan A. Supple ◽  
Ashley Byrne ◽  
James A. Cahill ◽  
Luiz Lehmann Coutinho ◽  
...  
Keyword(s):  
Landscape Connectivity ◽  
Geographic Range ◽  
Long Term Effects ◽  
Genetic Rescue ◽  
Isolated Populations ◽  
Mountain Lions ◽  
Mountain Lion ◽  
Genome Wide ◽  
Inbred Populations ◽  
North And South America

Introduction paragraph/AbstractAcross the geographic range of mountain lions, which includes much of North and South America, populations have become increasingly isolated due to human persecution and habitat loss. To explore the genomic consequences of these processes, we assembled a high-quality mountain lion genome and analyzed a panel of resequenced individuals from across their geographic range. We found strong geographical structure and signatures of severe inbreeding in all North American populations. Tracts of homozygosity were rarely shared among populations, suggesting that assisted gene flow would restore local genetic diversity. However, the genome of an admixed Florida panther that descended from a translocated individual from Central America had surprisingly long tracts of homozygosity, indicating that genomic gains from translocation were quickly lost by local inbreeding. Thus, to sustain diversity, genetic rescue will need to occur at regular intervals, through repeated translocations or restoring landscape connectivity. Mountain lions provide a rare opportunity to examine the potential to restore diversity through genetic rescue, and to observe the long-term effects of translocation. Our methods and results provide a framework for genome-wide analyses that can be applied to the management of small and isolated populations.

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