Cryptic speciation reversal in the Etheostoma zonale (Teleostei: Percidae) species group, with an examination of the effect of recombination and introgression on species tree inference

Mitochondrial and nuclear introgression among closely related taxa can greatly complicate the process of determining their phylogenetic relationships. In the Central Highlands of North America, many fish taxa have undergone introgression; in this study, we demonstrate the existence of an unusual introgression event in the Etheostoma zonale species group. We used one mitochondrial and seven nuclear loci to determine the relationships of the taxa within the E. zonale group, and their degree of differentiation. We found evidence of multiple divergent populations within each species; much of the divergence within species has taken place during the Pleistocene. We also found evidence of a previously unknown cryptic species in the Upper Tennessee River which diverged from the remainder of the group during the Pliocene, and has undergone mitochondrial and nuclear introgression with E. zonale, in an apparent process of speciation reversal. We examined the effects that using varying types of rec...

近缘类群间的线粒体与核基因渐渗，会极大复杂化其系统发育关系的解析工作。在北美中部高地，诸多鱼类类群均发生过基因渐渗事件；本研究证实，带镖鲈物种组（Etheostoma zonale species group）中存在一例非同寻常的渐渗事件。我们采用1个线粒体基因座与7个核基因座，对带镖鲈物种组内各类群的系统发育关系及其分化程度进行了解析。研究发现，每一物种内部均存在多个分化显著的种群；物种内的多数分化事件均发生于更新世时期。此外，我们在田纳西河上游区域发现了一种此前未被记录的隐存物种，该物种在上新世时期便与该物种组的其余类群产生分化，并与带镖鲈发生了线粒体与核基因渐渗，这一过程疑似属于物种逆转事件。我们还探究了使用不同类型的重组...