Pseudo-parallel patterns of disjunctions in an Arctic-alpine plant lineage

Disjunct distributions have intrigued biologists for centuries. Investigating these biogeographic patterns provides insight into speciation and biodiversity at multiple spatial and phylogenetic scales. Some disjunctions have been intensively studied, yet others have been largely overlooked and remain poorly understood. Among the lesser-known disjunction patterns is that between the mountain ranges of western North America. Flora and fauna endemic to the mountains of this region provide important systems for investigating causes and results of disjunctions, given the relatively recent geological formation of this area and the intense climatic fluctuations that have occurred since its formation. In Micranthes (Saxifragaceae), which has high rates of montane endemism, two species, M. bryophora and M. tolmiei, show this biogeographical pattern. By reconstructing a time-calibrated phylogeny based on 518 low-copy nuclear markers and including multiple populations of each species from the Coas...间断分布格局已令生物学家们关注数百年之久。对这类生物地理格局展开研究，可为阐明不同空间与系统发育尺度下的物种形成过程与生物多样性维持机制提供重要视角。部分间断分布现象已得到深入探究，但其余多数则长期被忽视，相关认知仍较为匮乏。在鲜为人知的间断分布格局中，北美西部山脉间的分布间断便是典型一例。该区域山地特有的动植物类群，为研究间断分布的成因与演化结果提供了优质研究体系——这得益于该区域地质形成年代较新，且自形成以来经历了剧烈的气候波动。在山地特有性极高的Micranthes属（虎耳草科 Saxifragaceae）中，M. bryophora与M. tolmiei两个物种便呈现出上述生物地理分布间断格局。本研究基于518个低拷贝核标记构建时间校准系统发育树，并纳入了各物种在海岸...