Data from: A passerine bird's evolution corroborates the geologic history of the island of New Guinea

New Guinea is a biologically diverse island, with a unique geologic history and topography that has likely played a role in the evolution of species. Few island-wide studies, however, have examined the phylogeographic history of lowland species. The objective of this study was to examine patterns of phylogeographic variation of a common and widespread New Guinean bird species (Colluricincla megarhyncha). Specifically, we test the mechanisms hypothesized to cause geographic and genetic variation (e.g., vicariance, isolation by distance and founder-effect with dispersal). To accomplish this, we surveyed three regions of the mitochondrial genome and a nuclear intron and assessed differences among 23 of the 30 described subspecies from throughout their range. We found support for eight highly divergent lineages within C. megarhyncha. Genetic lineages were found within continuous lowland habitat or on smaller islands, but all individuals within clades were not necessarily structured by predicted biogeographic barriers. There was some evidence of isolation by distance and potential founder-effects. Mitochondrial DNA sequence divergence among lineages was at a level often observed among different species or even genera of birds (5-11%), suggesting lineages within regions have been isolated for long periods of time. When topographical barriers were associated with divergence patterns, the estimated divergence date for the clade coincided with the estimated time of barrier formation. We also found that dispersal distance and range size are positively correlated across lineages. Evidence from this research suggests that different phylogeographic mechanisms concurrently structure lineages of C. megarhyncha and are not mutually exclusive. These lineages are a result of evolutionary forces acting at different temporal and spatial scales concordant with New Guinea’s geological history.

新几内亚是生物多样性极为丰富的岛屿，其独特的地质历史与地形地貌极有可能在物种演化进程中发挥了关键作用。然而目前鲜有基于全岛尺度的研究，探讨低地物种的系统发育地理学（phylogeography）历史。本研究旨在解析一种分布广泛且常见的新几内亚鸟类——厚嘴噪鹛（Colluricincla megarhyncha）的系统发育变异模式。具体而言，我们验证了假说提出的、可导致地理与遗传变异的多种机制，例如地理分隔、距离隔离以及伴随扩散的奠基者效应。为达成研究目标，我们对线粒体基因组的三个区域以及一段核内含子进行了测序分析，并对该物种分布范围内已描述的30个亚种中的23个开展了遗传差异评估。研究结果显示，厚嘴噪鹛内存在8个高度分化的遗传谱系。这些遗传谱系既分布于连续的低地生境中，也存在于小型岛屿之上，但进化枝内的所有个体未必会按照预期的生物地理屏障形成对应的遗传结构。本研究发现了距离隔离与潜在奠基者效应的相关证据。不同谱系间的线粒体DNA序列分歧率介于5%至11%之间，这一水平通常可见于鸟类不同物种甚至不同属之间，这表明各区域内的谱系已处于长期隔离状态。当地形屏障与遗传分化模式存在关联时，该进化枝的估算分化时间与屏障形成的估算时间相吻合。我们还发现，谱系的扩散距离与分布范围大小呈正相关关系。本研究的证据表明，多种系统发育地理学机制共同塑造了厚嘴噪鹛的谱系结构，且这些机制并非互斥。这些谱系是在不同时空尺度下的演化作用力共同影响下形成的，与新几内亚的地质历史相契合。