Data from: Genetic and demographic founder effects have long-term fitness consequences for colonising populations

Colonisation is a fundamental ecological and evolutionary process that drives the distribution and abundance of organisms. The initial ability of colonists to establish is determined largely by the number of founders and their genetic background. We explore the importance of these demographic and genetic properties for longer term persistence and adaptation of populations colonising a novel habitat using experimental populations of Tribolium castaneum. We introduced individuals from three genetic backgrounds (inbred – outbred) into a novel environment at three founding sizes (2–32), and tracked populations for seven generations. Inbreeding had negative effects, whereas outbreeding generally had positive effects on establishment, population growth and long-term persistence. Severe bottlenecks due to small founding sizes reduced genetic variation and fitness but did not prevent adaptation if the founders originated from genetically diverse populations. Thus, we find important and largely independent roles for both demographic and genetic processes in driving colonisation success.

定殖（Colonisation）是驱动生物分布与种群丰度的核心生态与进化过程。定居者的初始建群能力，在很大程度上取决于建群者数量及其遗传背景。本研究以赤拟谷盗（Tribolium castaneum）的实验种群为对象，探究上述种群统计与遗传特征对开拓新生境的种群长期存续与适应性演化的重要性。我们将三种遗传背景（近交型—远交型）的个体以三种建群规模（2~32只）引入新生境，并对种群进行了7个世代的追踪监测。近交对建群、种群增长及长期存续均产生负面影响，而远交通常带来正向效应。建群规模过小导致的严重瓶颈效应会降低种群遗传变异与适合度，但如果建群者源自遗传多样的种群，则不会阻碍适应性演化。综上，本研究发现，种群统计过程与遗传过程在驱动定殖成功中均发挥重要且基本独立的作用。