913 research outputs found

    Special Issue: Evolutionary perspectives on salmonid conservation and management

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    This special issue of Evolutionary Applications comprises 15 papers that illustrate how evolutionary principles can inform the conservation and management of salmonid fishes. Several papers address the past evolutionary history of salmonids to gain insights into their likely plastic and genetic responses to future environmental change. The remaining papers consider potential evolutionary responses to climate warming, biological invasions, artificial propagation, habitat alteration, and harvesting. All of these papers consider how such influences might alter selective regimes, which should then favour plastic or genetic responses. Some of the papers then go on to document such responses, at least some of which are genetically based and adaptive. Despite the different approaches and target species, all of the papers argue for the importance of evolutionary considerations in the conservation and management of salmonids

    A Desire for the Dark Side: An Examination of Individual Personality Characteristics and Their Desire for Adverse Characteristics in Leaders

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    Powerful and charismatic leaders are often highly desired by organizations and the followers that work within them. However, leaders who are highly skilled at developing relationships and accomplishing what they need to are often those individuals who rate very high on personality traits or characteristics that are considered “dark.” Although much attention has been paid to leaders and dark characteristics, we know much less regarding the dark side of leadership and followers’ susceptibility to these leaders. This article investigates the extent to which follower traits (i.e., the dark triad and the Big Five) predict a follower’s propensity to accept leader behaviors indicative of psychopathy (measured via the Hare P-Scan). Results suggest a follower’s psychopathy leads to the desire for dark leaders. Implications and future research suggest a more in-depth examination of followers and why certain individuals desire dark leadership, as well as examining negative environments

    Molecular techniques reveal cryptic life history and demographic processes of a critically endangered marine turtle

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    The concept of ‘effective population size’ (Ne), which quantifies how quickly a population will lose genetic variability, is one of the most important contributions of theoretical evolutionary biology to practical conservation management. Ne is often much lower than actual population size: how much so depends on key life history and demographic parameters, such as mating systems and population connectivity, that often remain unknown for species of conservation concern. Molecular techniques allow the indirect study of these parameters, as well as the estimation of current and historical Ne. Here, we use genotyping to assess the genetic health of an important population of the critically endangered hawksbill turtle (Eretmochelys imbricata), a slow-to-mature, difficult-to-observe species with a long history of severe overhunting. Our results were surprisingly positive: we found that the study population, located in the Republic of Seychelles, Indian Ocean, has a relatively large Ne, estimated to exceed 1000, and showed no evidence of a recent reduction in Ne (i.e. no genetic bottleneck). Furthermore, molecular inferences suggest the species' mating system is conducive to maintaining a large Ne, with a relatively large and widely distributed male population promoting considerable gene flow amongst nesting sites across the Seychelles area. This may also be reinforced by the movement of females between nesting sites. Our study underlines how molecular techniques can help to inform conservation biology. In this case our results suggest that this important hawksbill population is starting from a relatively strong position as it faces new challenges, such as global climate change

    Luscious: A High Quality Dessert Pear for the North

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    This bulletin contains a brief introduction to the Luscious desert pear

    Understanding and Estimating Effective Population Size for Practical Application in Marine Species Management

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    Effective population size (Ne) determines the strength of genetic drift in a population and has long been recognized as an important parameter for evaluating conservation status and threats to genetic health of populations. Specifically, an estimate of Ne is crucial to management because it integrates genetic effects with the life history of the species, allowing for predictions of a population’s current and future viability. Nevertheless, compared with ecological and demographic parameters, Ne has had limited influence on species management, beyond its application in very small populations. Recent developments have substantially improved Ne estimation; however, some obstacles remain for the practical application of Ne estimates. For example, the need to define the spatial and temporal scale of measurement makes the concept complex and sometimes difficult to interpret. We reviewed approaches to estimation of Ne over both long-term and contemporary time frames, clarifying their interpretations with respect to local populations and the global metapopulation. We describe multiple experimental factors affecting robustness of contemporary Ne estimates and suggest that different sampling designs can be combined to compare largely independent measures of Ne for improved confidence in the result. Large populations with moderate gene flow pose the greatest challenges to robust estimation of contemporary Ne and require careful consideration of sampling and analysis to minimize estimator bias. We emphasize the practical utility of estimating Ne by highlighting its relevance to the adaptive potential of a population and describing applications in management of marine populations, where the focus is not always on critically endangered populations. Two cases discussed include the mechanisms generating Ne estimates many orders of magnitude lower than census N in harvested marine fishes and the predicted reduction in Ne from hatchery-based population supplementation

    Understanding and Estimating Effective Population Size for Practical Application in Marine Species Management

    Get PDF
    Effective population size (Ne) determines the strength of genetic drift in a population and has long been recognized as an important parameter for evaluating conservation status and threats to genetic health of populations. Specifically, an estimate of Ne is crucial to management because it integrates genetic effects with the life history of the species, allowing for predictions of a population’s current and future viability. Nevertheless, compared with ecological and demographic parameters, Ne has had limited influence on species management, beyond its application in very small populations. Recent developments have substantially improved Ne estimation; however, some obstacles remain for the practical application of Ne estimates. For example, the need to define the spatial and temporal scale of measurement makes the concept complex and sometimes difficult to interpret. We reviewed approaches to estimation of Ne over both long-term and contemporary time frames, clarifying their interpretations with respect to local populations and the global metapopulation. We describe multiple experimental factors affecting robustness of contemporary Ne estimates and suggest that different sampling designs can be combined to compare largely independent measures of Ne for improved confidence in the result. Large populations with moderate gene flow pose the greatest challenges to robust estimation of contemporary Ne and require careful consideration of sampling and analysis to minimize estimator bias. We emphasize the practical utility of estimating Ne by highlighting its relevance to the adaptive potential of a population and describing applications in management of marine populations, where the focus is not always on critically endangered populations. Two cases discussed include the mechanisms generating Ne estimates many orders of magnitude lower than census N in harvested marine fishes and the predicted reduction in Ne from hatchery-based population supplementation

    Anomalous thermal maturities caused by carbonaceous sediments

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    Sedimentary rocks such as coal and carbonaceous mudstone which contain abundant carbonaceous matter are characterized by thermal conductivity much lower than that exhibited by other common rock types, by a factor of 5–10. As a result, temperature gradients in such sediments can range up to 0.25 °Cm -1 even under conditions of average heat flow. When such steep gradients extend over a significant sedimentary thickness, temperatures of underlying rock units are elevated, causing both organic and inorganic phases to record what seem to be anomalously high levels of thermal maturity. This carbonaceous blanket insulating effect may help to explain unusual levels of maturity observed at shallow depths in the Appalachian Basin, Michigan Basin and other regions of the world with significant carbonaceous strata.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73579/1/j.1365-2117.1994.tb00074.x.pd

    The genetic history of Greenlandic-European contact.

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    The Inuit ancestors of the Greenlandic people arrived in Greenland close to 1,000 years ago.1 Since then, Europeans from many different countries have been present in Greenland. Consequently, the present-day Greenlandic population has ∼25% of its genetic ancestry from Europe.2 In this study, we investigated to what extent different European countries have contributed to this genetic ancestry. We combined dense SNP chip data from 3,972 Greenlanders and 8,275 Europeans from 14 countries and inferred the ancestry contribution from each of these 14 countries using haplotype-based methods. Due to the rapid increase in population size in Greenland over the past ∼100 years, we hypothesized that earlier European interactions, such as pre-colonial Dutch whalers and early German and Danish-Norwegian missionaries, as well as the later Danish colonists and post-colonial immigrants, all contributed European genetic ancestry. However, we found that the European ancestry is almost entirely Danish and that a substantial fraction is from admixture that took place within the last few generations

    Ecological and evolutionary consequences of alternative sex-change pathways in fish

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    Sequentially hermaphroditic fish change sex from male to female (protandry) or vice versa (protogyny), increasing their fitness by becoming highly fecund females or large dominant males, respectively. These life-history strategies present different social organizations and reproductive modes, from near-random mating in protandry, to aggregate- and harem-spawning in protogyny. Using a combination of theoretical and molecular approaches, we compared variance in reproductive success (V k*) and effective population sizes (N e) in several species of sex-changing fish. We observed that, regardless of the direction of sex change, individuals conform to the same overall strategy, producing more offspring and exhibiting greater V k* in the second sex. However, protogynous species show greater V k*, especially pronounced in haremic species, resulting in an overall reduction of N e compared to protandrous species. Collectively and independently, our results demonstrate that the direction of sex change is a pivotal variable in predicting demographic changes and resilience in sex-changing fish, many of which sustain highly valued and vulnerable fisheries worldwide

    Aboriginal-mainstream partnerships: Exploring the challenges and enhancers of a collaborative service arrangement for Aboriginal clients with substance use issues

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    Background: Partnerships between different health services are integral to addressing the complex health needs of vulnerable populations. In Australia, partnerships between Aboriginal community controlled and mainstream services can extend health care options and improve the cultural safety of services. However, although government funding supports such collaborations, many factors can cause these arrangements to be tenuous, impacting the quality of health care received. Research was undertaken to explore the challenges and enhancers of a government initiated service partnership between an Aboriginal Community Controlled alcohol and drug service and three mainstream alcohol rehabilitation and support services. Methods. Sixteen staff including senior managers (n=5), clinical team leaders (n=5) and counsellors (n=6) from the four services were purposively recruited and interviewed. Interviews were semi-structured and explored staff experience of the partnership including the client intake and referral process, shared client care, inter-service communication and ways of working. Results & discussion. Communication issues, partner unfamiliarity, 'mainstreaming' of Aboriginal funding, divergent views regarding staff competencies, client referral issues, staff turnover and different ways of working emerged as issues, emphasizing the challenges of working with a population with complex issues in a persistent climate of limited resourcing. Factors enhancing the partnership included adding a richness and diversity to treatment possibilities and opportunities to explore different, more culturally appropriate ways of working. Conclusion: While the literature strongly advises partnerships be suitably mature before commencing service delivery, the reality of funding cycles may require partnerships become operational before relationships are adequately consolidated. Allowing sufficient time and funding for both the operation and relational aspects of a partnership is critical, with support for partners to regularly meet and workshop arrangements. Documentation that makes clear and embeds working arrangements between partners is important to ameliorate many of the issues that can arise. Given the historical undercurrents, flexible approaches are required to focus on strengths that contribute to progress, even if incremental, rather than on weaknesses which can undermine efforts. This research offers important lessons to assist other services collaborating in post-colonial settings to offer treatment pathways for vulnerable populations. © 2013 Taylor et al.; licensee BioMed Central Ltd
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