174 research outputs found
Reeves’ muntjac populations continue to grow and spread across Great Britain and are invading continental Europe
The appropriate response for controlling an invasive non-native species depends on the extent to which its invasion has progressed, which can be revealed by information on its distribution and abundance. Reeves’ muntjac is a native deer to China and Taiwan, but has been introduced and become well-established in Great Britain. Moreover, in recent years, reports and verified records in the wild from other European countries have become more frequent. We reviewed the status of Reeves’ muntjac in Britain and evaluated its national range expansion from 2002 to 2016. While the British population appears to have tripled in size since 1995, the rate at which it has expanded its range seems to have peaked at approximately 12% per year between 2002 and 2005 and has since declined. We also consolidated observations on its international distribution, including a conservative evaluation of its presence in zoological collections. We predict that this species could expand its range to include every European country, although the availability of suitable landcover and climate is likely to vary substantially between countries. To prevent the significant impacts to conservation interests that have been observed in Great Britain from extending across Europe, national administrations should consider eradicating Reeves’ muntjac while that is still feasible
Long Distance Dispersal of Zooplankton Endemic to Isolated Mountaintops - an Example of an Ecological Process Operating on an Evolutionary Time Scale
Recent findings suggest a convergence of time scales between ecological and evolutionary processes which is usually explained in terms of rapid micro evolution resulting in evolution on ecological time scales. A similar convergence, however, can also emerge when slow ecological processes take place on evolutionary time scales. A good example of such a slow ecological process is the colonization of remote aquatic habitats by passively dispersed zooplankton. Using variation at the protein coding mitochondrial COI gene, we investigated the balance between mutation and migration as drivers of genetic diversity in two Branchipodopsis fairy shrimp species (Crustacea, Anostraca) endemic to remote temporary rock pool clusters at the summit of isolated mountaintops in central South Africa. We showed that both species colonized the region almost simultaneously c. 0.8 My ago, but exhibit contrasting patterns of regional genetic diversity and demographic history. The haplotype network of the common B. cf. wolfi showed clear evidence of 11 long distance dispersal events (up to 140 km) with five haplotypes that are shared among distant inselbergs, as well as some more spatially isolated derivates. Similar patterns were not observed for B. drakensbergensis presumably since this rarer species experienced a genetic bottleneck. We conclude that the observed genetic patterns reflect rare historic colonization events rather than frequent ongoing gene flow. Moreover, the high regional haplotype diversity combined with a high degree of haplotype endemicity indicates that evolutionary- (mutation) and ecological (migration) processes in this system operate on similar time scales
Monitoring status and trends in genetic diversity for the Convention on Biological Diversity: An ongoing assessment of genetic indicators in nine countries
Recent scientific evidence shows that genetic diversity must be maintained, managed, and monitored to protect biodiversity and nature's contributions to people. Three genetic diversity indicators, two of which do not require DNA-based assessment, have been proposed for reporting to the Convention on Biological Diversity and other conservation and policy initiatives. These indicators allow an approximation of the status and trends of genetic diversity to inform policy, using existing demographic and geographic information. Application of these indicators has been initiated and here we describe ongoing efforts in calculating these indicators with examples. We specifically describe a project underway to apply these indicators in nine countries, provide example calculations, address concerns of policy makers and implementation challenges, and describe a roadmap for further development and deployment, incorporating feedback from the broader community. We also present guidance documents and data collection tools for calculating indicators. We demonstrate that Parties can successfully and cost-effectively report these genetic diversity indicators with existing biodiversity observation data, and, in doing so, better conserve the Earth's biodiversity
Genetic diversity is considered important but interpreted narrowly in country reports to the Convention on Biological Diversity: Current actions and indicators are insufficient
International agreements such as the Convention on Biological Diversity (CBD) have committed to conserve, and sustainably and equitably use, biodiversity. The CBD is a vital instrument for global conservation because it guides 195 countries and the European Union in setting priorities and allocating resources, and requires regular reporting on progress. However, the CBD and similar policy agreements have often neglected genetic diversity. This is a critical gap because genetic diversity underlies adaptation to environmental change and ecosystem resilience. Here we aim to inform future policy, monitoring, and reporting efforts focused on limiting biodiversity loss by conducting the largest yet evaluation of how Parties to the CBD report on genetic diversity. A large, globally representative sample of 114 CBD National Reports was examined to assess reported actions, progress, values and indicators related to genetic diversity. Although the importance of genetic diversity is recognized by most Parties to the CBD, genetic diversity targets mainly addressed variation within crops and livestock (a small fraction of all species). Reported actions to conserve genetic diversity primarily concerned ex situ facilities and legislation, rather than monitoring and in situ intervention. The most commonly reported status indicators are not well correlated to maintaining genetic diversity. Lastly, few reports mentioned genetic monitoring using DNA data, indigenous use and knowledge of genetic diversity, or development of strategies to conserve genetic diversity. We make several recommendations for the post-2020 CBD Biodiversity Framework, and similar efforts such as IPBES, to improve awareness, assessment, and monitoring of genetic diversity, and facilitate consistent and complete reporting in the future
Genetic diversity is considered important but interpreted narrowly in country reports to the Convention on Biological Diversity: current actions and indicators are insufficient
20openInternationalInternational coauthor/editorInternational agreements such as the Convention on Biological Diversity (CBD) have committed to conserve, and
sustainably and equitably use, biodiversity. The CBD is a vital instrument for global conservation because it
guides 195 countries and the European Union in setting priorities and allocating resources, and requires regular
reporting on progress. However, the CBD and similar policy agreements have often neglected genetic diversity.openHoban, Sean; Campbell, Catriona D.; da Silva, Jessica M.; Ekblom, Robert; Funk, W. Chris; Garner, Brittany A.; Godoy, José A.; Kershaw, Francine; MacDonald, Anna J.; Mergeay, Joachim; Minter, Melissa; O'Brien, David; Vinas, Ivan Paz; Pearson, Sarah K.; Pérez-Espona, Sílvia; Potter, Kevin M.; Russo, Isa-Rita M.; Segelbacher, Gernot; Vernesi, Cristiano; Hunter, Margaret E.Hoban, S.; Campbell, C.D.; da Silva, J.M.; Ekblom, R.; Funk, W.C.; Garner, B.A.; Godoy, J.A.; Kershaw, F.; Macdonald, A.J.; Mergeay, J.; Minter, M.; O'Brien, D.; Vinas, I.P.; Pearson, S.K.; Pérez-Espona, S.; Potter, K.M.; Russo, I.M.; Segelbacher, G.; Vernesi, C.; Hunter, M.E
Strong differences in the clonal variation of two Daphnia species from mountain lakes affected by overwintering strategy
<p>Abstract</p> <p>Background</p> <p>The population structure of cyclical parthenogens such as water fleas is strongly influenced by the frequency of alternations between sexual and asexual (parthenogenetic) reproduction, which may differ among populations and species. We studied genetic variation within six populations of two closely related species of water fleas of the genus <it>Daphnia </it>(Crustacea, Cladocera). <it>D. galeata </it>and <it>D. longispina </it>both occur in lakes in the Tatra Mountains (Central Europe), but their populations show distinct life history strategies in that region. In three studied lakes inhabited by <it>D. galeata</it>, daphnids overwinter under the ice as adult females. In contrast, in lakes inhabited by <it>D. longispina</it>, populations apparently disappear from the water column and overwinter as dormant eggs in lake sediments. We investigated to what extent these different strategies lead to differences in the clonal composition of late summer populations.</p> <p>Results</p> <p>Analysis of genetic variation at nine microsatellite loci revealed that clonal richness (expressed as the proportion of different multilocus genotypes, MLGs, in the whole analysed sample) consistently differed between the two studied species. In the three <it>D. longispina </it>populations, very high clonal richness was found (MLG/N ranging from 0.97 to 1.00), whereas in <it>D. galeata </it>it was much lower (0.05 to 0.50). The dominant MLGs in all <it>D. galeata </it>populations were heterozygous at five or more loci, suggesting that such individuals all represented the same clonal lineages rather than insufficiently resolved groups of different clones.</p> <p>Conclusions</p> <p>The low clonal diversities and significant deviations from Hardy-Weinberg equilibrium in <it>D. galeata </it>populations were likely a consequence of strong clonal erosion over extended periods of time (several years or even decades) and the limited influence of sexual reproduction. Our data reveal that populations of closely related <it>Daphnia </it>species living in relatively similar habitats (permanent, oligotrophic mountain lakes) within the same region may show strikingly different genetic structures, which most likely depend on their reproductive strategy during unfavourable periods. We assume that similar impacts of life history on population structures are also relevant for other cyclical parthenogen groups. In extreme cases, prolonged clonal erosion may result in the dominance of a single clone within a population, which might limit its microevolutionary potential if selection pressures suddenly change.</p
Global commitments to conserving and monitoring genetic diversity are now necessary and feasible
Global conservation policy and action have largely neglected protecting and monitoring genetic diversity—one of the three main pillars of biodiversity. Genetic diversity (diversity within species) underlies species’ adaptation and survival, ecosystem resilience, and societal innovation. The low priority given to genetic diversity has largely been due to knowledge gaps in key areas, including the importance of genetic diversity and the trends in genetic diversity change; the perceived high expense and low availability and the scattered nature of genetic data; and complicated concepts and information that are inaccessible to policymakers. However, numerous recent advances in knowledge, technology, databases, practice, and capacity have now set the stage for better integration of genetic diversity in policy instruments and conservation efforts. We review these developments and explore how they can support improved consideration of genetic diversity in global conservation policy commitments and enable countries to monitor, report on, and take action to maintain or restore genetic diversity
Genetic diversity targets and indicators in the CBD post-2020 Global Biodiversity Framework must be improved
The 196 parties to the Convention on Biological Diversity (CBD) will soon agree to a post-2020 global framework for conserving the three elements of biodiversity (genetic, species, and ecosystem diversity) while ensuring sustainable development and benefit sharing. As the most significant global conservation policy mechanism, the new CBD framework has far-reaching consequences- it will guide conservation actions and reporting for each member country until 2050. In previous CBD strategies, as well as other major conservation policy mechanisms, targets and indicators for genetic diversity (variation at the DNA level within species, which facilitates species adaptation and ecosystem function) were undeveloped and focused on species of agricultural relevance. We assert that, to meet global conservation goals, genetic diversity within all species, not just domesticated species and their wild relatives, must be conserved and monitored using appropriate metrics. Building on suggestions in a recent Letter in Science (Laikre et al., 2020) we expand argumentation for three new, pragmatic genetic indicators and modifications to two current indicators for maintaining genetic diversity and adaptive capacity of all species, and provide guidance on their practical use. The indicators are: 1) the number of populations with effective population size above versus below 500, 2) the proportion of populations maintained within species, 3) the number of species and populations in which genetic diversity is monitored using DNA-based methods. We also present and discuss Goals and Action Targets for post-2020 biodiversity conservation which are connected to these indicators and underlying data. These pragmatic indicators and goals have utility beyond the CBD; they should benefit conservation and monitoring of genetic diversity via national and global policy for decades to come.
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