LSU Museum of Natural Science (Ichthyology), Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.
PLoS One. 2013 Aug 19;8(8):e71162. doi: 10.1371/journal.pone.0071162. eCollection 2013.
The contrasting distribution of species diversity across the major lineages of cichlids makes them an ideal group for investigating macroevolutionary processes. In this study, we investigate whether different rates of diversification may explain the disparity in species richness across cichlid lineages globally. We present the most taxonomically robust time-calibrated hypothesis of cichlid evolutionary relationships to date. We then utilize this temporal framework to investigate whether both species-rich and depauperate lineages are associated with rapid shifts in diversification rates and if exceptional species richness can be explained by clade age alone. A single significant rapid rate shift increase is detected within the evolutionary history of the African subfamily Pseudocrenilabrinae, which includes the haplochromins of the East African Great Lakes. Several lineages from the subfamilies Pseudocrenilabrinae (Australotilapiini, Oreochromini) and Cichlinae (Heroini) exhibit exceptional species richness given their clade age, a net rate of diversification, and relative rates of extinction, indicating that clade age alone is not a sufficient explanation for their increased diversity. Our results indicate that the Neotropical Cichlinae includes lineages that have not experienced a significant rapid burst in diversification when compared to certain African lineages (rift lake). Neotropical cichlids have remained comparatively understudied with regard to macroevolutionary patterns relative to African lineages, and our results indicate that of Neotropical lineages, the tribe Heroini may have an elevated rate of diversification in contrast to other Neotropical cichlids. These findings provide insight into our understanding of the diversification patterns across taxonomically disparate lineages in this diverse clade of freshwater fishes and one of the most species-rich families of vertebrates.
慈鲷目主要支系的物种多样性分布差异显著，这使它们成为研究宏观进化过程的理想群体。在这项研究中，我们调查了不同的多样化速率是否可以解释全球慈鲷目支系之间物种丰富度的差异。我们提出了迄今为止最具分类学稳健性的慈鲷进化关系时间校准假说。然后，我们利用这个时间框架来调查丰富的和贫化的支系是否都与多样化速率的快速变化有关，以及是否可以仅通过分支年龄来解释异常的物种丰富度。在非洲副科拟丽鱼亚科的进化历史中，检测到一个单一的显著快速率变化增加，其中包括东非大裂谷的哈氏丽鱼。来自副科拟丽鱼亚科（澳丽鱼属、口孵非鲫属）和丽鱼亚科（英雄鱼属）的几个支系表现出异常的物种丰富度，考虑到它们的分支年龄、净多样化率和相对灭绝率，这表明分支年龄本身并不是它们增加多样性的充分解释。我们的结果表明，与某些非洲支系（裂谷湖）相比，新热带丽鱼亚科的某些支系没有经历显著的多样化快速爆发。与非洲支系相比，新热带丽鱼亚科在宏观进化模式方面的研究相对较少，我们的结果表明，在新热带丽鱼亚科中，英雄鱼族可能比其他新热带丽鱼具有更高的多样化率。这些发现为我们理解这个多样化的淡水鱼类类群和脊椎动物中物种最丰富的科之一的分类学差异支系中的多样化模式提供了深入的了解。
