Timetree of Aselloidea reveals species diversification dynamics in groundwater

A key challenge for biologists is to document and explain global patterns of diversification in a wide range of environments. Here, we explore patterns of continental-scale diversification in a groundwater species-rich clade, the superfamily Aselloidea (Pancrustacea: Isopoda). Our analyses supported a constant diversification rate during most of the course of Aselloidea evolution, until 4–15 Ma when diversification rates started to decrease. This constant accumulation of lineages challenges the view that groundwater species diversification in temperate regions might have been primarily driven by major changes in physical environment leading to the extinction of surface populations and subsequent synchronous isolation of multiple groundwater populations. Rather than acting synchronously over broad geographic regions, factors causing extinction of surface populations and subsequent reproductive isolation of groundwater populations may act in a local and asynchronous manner, thereby result...

生物学家所面临的一项核心挑战，是在多样的生境中记录并阐释全球生物多样化格局。本研究以一类物种丰富的地下水生演化支——隶属于泛甲壳类（Pancrustacea）：等足目（Isopoda）的潮虫总科（Aselloidea）为研究对象，探究其大陆尺度的多样化格局。分析结果表明，在潮虫总科演化的绝大多数阶段，其多样化速率均保持恒定；直至400万至1500万年前（Ma，百万年），多样化速率才开始出现下降。这种谱系的持续积累，与“温带地区地下水物种的多样化主要由物理环境的重大变化驱动，进而引发地表种群灭绝，并随后导致多个地下水种群发生同步生殖隔离”的主流观点相悖。相较于在广阔地理区域内同步发挥作用，引发地表种群灭绝、后续地下水种群生殖隔离的相关因素，或许是以局域、异步的方式产生作用，进而导致……