Abstract
BackgroundThe historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism. However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. In this study, we examined the detailed diversification history of Primula sect. Armerina, and used biogeographic analysis and macro-evolutionary modeling to investigate a series of different questions concerning the evolution of the geographical and ecological distribution of the species in this section.ResultsWe sequenced five chloroplast and one nuclear genes for species of Primula sect. Armerina. Neither chloroplast nor nuclear trees support the monophyly of the section. The major incongruences between the two trees occur among closely related species and may be explained by hybridization. Our dating analyses based on the chloroplast dataset suggest that this section began to diverge from its relatives around 3.55 million years ago, largely coinciding with the last major uplift of the Qinghai-Tibet Plateau (QTP). Biogeographic analysis supports the origin of the section in the Himalayan Mountains and dispersal from the Himalayas to Northeastern QTP, Western QTP and Hengduan Mountains. Furthermore, evolutionary models of ecological niches show that the two P. fasciculata clades have significantly different climatic niche optima and rates of niche evolution, indicating niche evolution under climatic changes and further providing evidence for explaining their biogeographic patterns.ConclusionOur results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area. The Pliocene uplift of the QTP and following climatic changes most likely promoted both the inter- and intraspecific divergence of Primula sect. Armerina. This study also illustrates how niche evolution under climatic changes influences biogeographic patterns.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0445-7) contains supplementary material, which is available to authorized users.
Highlights
The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism
The topologies inferred from nuclear gene and concatenated chloroplast datasets are incongruent, which may mainly result from hybridization
Subsequent dispersals to the Hengduan Mountains, Northeastern Qinghai-Tibet Plateau (QTP) and Western QTP were considered as the consequence of the Pliocene uplift of the QTP and following climatic changes
Summary
The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism Their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. Understanding the processes that shape geographical and ecological distribution of biodiversity is one of the most challenging questions in evolutionary biology and ecology This is true for regions that have experienced rapid habitat changes and harbor high species diversity. Fragmentation can occur because of a lower success of establishment of individuals in some areas, which will limit the range of species [11] This process is primarily set by ecological factors, potentially including both abiotic and biotic variables [10,11,12]. A complete assessment of these processes, coupled with detailed analyses of biogeographic patterns of species distribution, should be used to help understand the distribution of species diversity [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
