The nature of genetic diversity, population size and adaptation: applications to conservation biology

遗传多样性的本质、种群规模和适应性：在保护生物学中的应用

• 批准号: 371575-2009
• 负责人: Fraser, Dylan
• 金额: $ 1.68万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=434885
• 关键词: nature; genetic; diversity; population; size

Human impacts on the environment have reduced the number of individuals within many wild species to very low levels. This is a concern to conservation biologists because species with small numbers may have an increased chance of going extinct. For example, small populations often exhibit low levels of genetic diversity, which is thought to reduce the likelihood that at least some individuals in such populations will survive and reproduce if the environment changes, what scientists refer to as reduced adaptability. Is there much evidence in nature of reduced adaptability in small populations? To date, it turns out that this has not been sufficiently studied to generalize, but it is important for society to know because it influences how we approach several conservation efforts to protect the environment and different species in the face of further human development. My proposed research program will examine relationships between population size, genetic diversity and adaptability in a salmonid fish species (brook charr) that is important to many commercial, recreational and aboriginal subsistence fisheries. Specifically, across multiple watersheds, I will determine whether small populations of brook charr do in fact exhibit reduced genetic diversity and adaptability relative to large populations. Field and laboratory studies will be carried out to understand (i) what environmental factors influence adaptability in natural populations of varying size, and (ii) how well small populations respond to environmental changes relative to large populations under conditions that will likely arise with future climate warming. For management agencies of several socio-economically important fish species across Canada, and for the international conservation community, my research will contribute significant new knowledge towards addressing several key environmental issues: (i) how large nature reserves should be to maintain viable populations of different species; (ii) whether small, isolated populations should receive a high priority for conservation; and (iii) how specific populations might respond to future environmental change (e.g. climate warming).

人类对环境的影响使许多野生物种的个体数量减少到非常低的水平。这是保护生物学家所关注的问题，因为数量少的物种灭绝的机会可能会增加。例如，小种群通常表现出低水平的遗传多样性，这被认为会降低这些种群中至少一些个体在环境变化时生存和繁殖的可能性，科学家称之为适应性降低。自然界中是否有大量证据表明小种群的适应性降低？到目前为止，事实证明，这还没有得到充分的研究来概括，但社会了解这一点很重要，因为它影响了我们如何在人类进一步发展的情况下采取一些保护措施来保护环境和不同物种。我提议的研究计划将研究鲑鱼物种（溪红点鲑）的种群规模、遗传多样性和适应性之间的关系，这对许多商业、娱乐和土著生计渔业都很重要。具体来说，在多个流域，我将确定是否小种群的布鲁克charr事实上表现出减少的遗传多样性和适应性相对于大种群。将进行实地和实验室研究，以了解（一）哪些环境因素影响不同规模的自然种群的适应性，以及（二）在未来气候变暖可能出现的条件下，小种群相对于大种群对环境变化的反应如何。对于加拿大各地的几个社会经济重要鱼类物种的管理机构，并为国际保护界，我的研究将有助于解决几个关键的环境问题的重要新知识：（一）多大的自然保护区应该保持不同物种的可行种群;（二）是否小，孤立的人口应得到高度优先的保护;及（iii）特定人口对未来环境变化（例如气候变暖）的反应。