Genetic structure and distribution of Parisotoma notabilis (Collembola) in Europe: Cryptic diversity, split of lineages and colonization patterns

Climatic and biome changes of the past million years influenced the population structure and genetic diversity of soil-living arthropods in Europe. However, their effects on the genetic structure of widespread and abundant soil animal species such as the Collembola Parisotoma notabilis remain virtually unknown. This generalist and parthenogenetic species is an early colonizer of disturbed habitats and often occurs in human modified environments. To investigate ancient climatic influence and recent distributions on the genetic structure of P. notabilis we analyzed populations on a pan-European scale using three genetic markers differing in substitution rates. The results showed that P. notabilis comprises several genetic lineages with distinct distribution ranges that diverged in the Miocene. Genetic distances of COI between lineages ranged between 15% and 18% and molecular clock estimates suggest Late Miocene divergences considering the standard arthropod rate of 2.3% per my. Compared to other soil-living arthropods like oribatid mites, European lineages of P. notabilis are rather young and genetically uniform. The close association with anthropogenic habitats presumably contributed to rapid spread in Europe.

过去百万年间的气候变化与生物群系变迁，影响了欧洲陆生节肢动物的种群结构与遗传多样性。然而，此类变化对广布优势土壤动物类群遗传结构的影响几乎尚未被阐明，例如弹尾目（Collembola）的*Parisotoma notabilis*。该物种为泛食性孤雌生殖类群，是扰动生境的早期拓殖者，常栖息于人类改造的环境中。为探究古气候影响与现今分布格局对*P. notabilis*遗传结构的作用机制，本研究以全欧尺度的种群为研究对象，采用替换速率各异的三种遗传标记开展分析。研究结果显示，*P. notabilis*包含多个遗传谱系，各谱系拥有独特的分布范围，其分化发生于中新世（Miocene）。谱系间的COI基因（Cytochrome C Oxidase Subunit I）遗传距离介于15%至18%之间；结合节肢动物标准替换速率（每百万年2.3%）进行分子钟估算，结果表明其分化发生于中新世晚期（Late Miocene）。相较于甲螨（Oribatida）等其他陆生节肢动物类群，欧洲地区的*P. notabilis*遗传谱系相对年轻，且遗传同质化程度较高。该类群与人为改造生境的紧密关联，或助力其在欧洲境内实现快速扩散。