The effects of interspecific biodiversity on intraspecific genetic diversity: a community genomics approach

进化和生态过程在当代时间尺度上相互作用。这导致了生态进化动力学，其中生态过程影响选择性环境(生态到生态反馈)，物种内丰度和组成的变化影响群落相互作用(生态到生态反馈)。在从环境到生态的方面，长期的遗传变异(=种内多样性)构成了适应的原材料。适应影响人口的持久性，因此是社区一级长期生态系统运作的一个重要组成部分。在生态-生态环境方面，物种多样性(=种间多样性)是选择性环境的一个重要方面，它影响任何局部物种的种群结构，从而影响物种内的长期遗传变异。有趣的是，在自然种群中，种间和种内的遗传多样性通常是正相关的(这种现象被称为物种-遗传多样性相关性SGDC)，但这种共同变异的原因在很大程度上是难以捉摸的。缺乏知识的一个原因是缺乏长期的实验研究，这些研究操纵物种多样性，从而能够评估种内遗传多样性从生态到进化的反馈。我们的项目是将种群遗传学和群落生态学结合起来的先驱，这种方法已成为众所周知的群落遗传学。群落遗传学使我们能够理解从物种组合到种群再到个体的所有多样性水平上的生态进化动态。与大多数以前的研究不同，我们将使用耶拿实验的实验环境，并将覆盖植物群落的所有物种。具体地说，我们解决了以下问题：(1)植物物种多样性是否影响植物种群种内现有遗传变异的维持？(2)植物物种多样性是否影响遗传变异在个体之间的分布？(3)在耶拿实验的18年实验操作中，植物物种的遗传组成是否发生了系统的变化？我们将使用现代测序基因分型方法，跨耶拿实验的整个物种多样性梯度，研究一组12个局部植物物种(每个功能组3个物种)的种内和个体间遗传多样性。然后我们将复制和推广到全套60个物种，包括2002年创建种群的样本(作为种子材料储存)和从当代高和低多样性群落采集的特定物种样本。这种方法使我们能够第一次在实地实验环境中测试群落的物种多样性如何影响种内遗传多样性，从而影响未来适应的潜力。

Evolutionary and ecological processes interact on contemporary timescales. This results in eco-evolutionary dynamics, in which ecological processes influence the selective environment (eco-to-evo feedbacks) and within-species changes in abundance and composition influence community interactions (evo-to-eco feedbacks). On the evo-to-eco side, standing genetic variation (= intraspecific diversity) constitutes the raw material for adaptation. Adaptation affects population persistence and thus represents an important component for long-term ecosystem functioning at the community level. On the eco-to-evo side, species diversity (= inter-specific diversity) constitutes a significant aspect of the selective environment that influences the population structure of any focal species and thus impacts on standing genetic variation within species. Intriguingly, inter- and intraspecific genetic diversity often covary positively in natural populations (a phenomenon known as species-genetic diversity correlations SGDC), but the causes for this covariation are largely elusive. One reason for the lack of knowledge is the paucity of long-term experimental studies that manipulate species diversity and thus allow an assessment of the eco-to-evo feedbacks on intraspecific genetic diversity. Our project pioneers in uniting population genetics and community ecology in an approach that has become known as community genetics. Community genetics allows us to understand the eco-evolutionary dynamics at all levels of diversity from species assemblages to populations to individuals. Unlike most previous studies, we will use the experimental setting of the Jena Experiment and will cover all species of the plant community. Specifically, we address the following questions: (1) Does plant species diversity influence the maintenance of intraspecific standing genetic variation of plant populations? (2) Does plant species diversity influence the distribution of genetic variation across individuals? (3) Did plant species systematically change in their genetic composition across the 18 years of experimental manipulation of the Jena Experiment? We will study intraspecific and inter-individual genetic diversity in a set of 12 focal plant species (three species per functional group) across the full species-diversity gradient of the Jena Experiment using modern genotyping-by-sequencing approaches. We will then replicate and generalize to the full set of 60 species, including samples from the founding population from 2002 (stored as seed materials) and species-specific samples taken from contemporary high and low diversity communities. This approach allows us to test for the first time in a field experimental setting how species diversity of the community affects intra-specific genetic diversity and thus the potential for future adaptation.