The diversification history of Podophylloideae (Berberidaceae) and its underlying drivers
Journal
Biodiversity Science
Series/Report No.
Biodiversity Science
Journal Volume
31
Journal Issue
7
Pages
23100
ISSN
1005-0094
Date Issued
2023-07-20
Author(s)
Abstract
Aims: In this study, our objective is to test the hypothesis that species-rich group possess higher net diversification rates. We focus on the subfamily Podophylloideae in Berberidaceae as our study system. Additionally, we aim to investigate the combined effects of biotic and abiotic factors on diversification rates. Methods: We reconstructed the phylogeny of Podophylloideae by using 77 chloroplast CDS genes and employing both maximum likelihood and Bayesian inference methods. To estimate divergence time, we used one second calibration and two fossil calibrations. Net diversification rates through time was estimated using BAMM. Additionally, we employed Hidden State Speciation and Extinction analysis (HiSSE) and Quantitative State Speciation and Extinction analysis (QuaSSE) to estimate the effect of four functional traits on diversification rate. Results: Molecular dating, based on 77 chloroplast CDS genes, showed that Podophylloideae originated approximately 92.75 Myr (95% HPD, 86.84‒95.84 Myr) with a crown age of 85 Myr (95% HPD, 73.19‒94.94 Myr). The net diversification rate began to increase around 23 Myr ago, and the most significant rate shift accrued approximately 21 Myr along the Epimedium stem branch. The analysis of state-dependent diversification rate indicated that taxa with nectar spur in subtropical East Asia possessed a higher net diversification rate. However, the specific spur length in Epimedium did not have a significant effect on net diversification rate. Furthermore, fruit type, the presence of aril, or the presence of aerial stems did not exert any significant effect on net diversification rate. Conclusions: Our results suggest that the variation in net diversification rates is driven by the presence of nectar spur and the intensification of the East Asian monsoon since the Miocene, which has shaped the discrepancy in species diversity in Podophylloideae.
Publisher
Biodiversity Science
Type
journal article