J Syst Evol ›› 2023, Vol. 61 ›› Issue (5): 733-747.DOI: 10.1111/jse.12998

• Research Articles • Previous Articles     Next Articles

Climatic niche evolution in Smilacaceae (Liliales) drives patterns of species diversification and richness between the Old and New World

Zhe-Chen Qi1,2†, Pan Li1†, Jun-Jie Wu1,2†, Alexander Gamisch3, Tuo Yang1, Yun-Peng Zhao1, Wu-Qing Xu1, Shi-Chao Chen4, Kenneth M. Cameron5*, Ying-Xiong Qiu6*, and Cheng-Xin Fu1*   

  1. 1 Laboratory of Systematic & Evolutionary Botany and Biodiversity, College of Life Sciences, Zhejiang University, Hangzhou 310058, China;
    2 Zhejiang Province Key Laboratory of Plant Secondary Metabolism and Regulation, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China;
    3 Department of Biosciences, University of Salzburg, Hellbrunnerstrasse 34, Salzburg 5020, Austria;
    4 School of Life Sciences and Technology, Tongji University, Shanghai 200092, China;
    5 Department of Botany, University of Wisconsin, Madison, WI 53706, USA;
    6 Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
    These authors contributed equally to this work.
    *Authors for correspondence. Kenneth M. Cameron. E-mail:kmcameron@wisc.edu;Ying-Xiong Qiu. E-mail:qyxhero@zju.edu.cn;Cheng-Xin Fu. E-mail:cxfu@zju.edu.cn
  • Received:2022-02-27 Accepted:2023-05-17 Online:2023-06-25 Published:2023-09-01

Abstract: Geographical variation in species richness in plant groups is determined by the interplay between historical, evolutionary, and ecological processes. However, the processes underlying the striking disparity in species richness between Asia and the Americas remain poorly understood. Here, we synthesize global phylogenetic and macroecological data on the diversification of Smilacaceae, deciphering potential drivers underlying the species diversity pattern biased toward Asia. We compiled global distributions of all Smilacaceae species, and reconstructed the biogeographic history and niche evolution using a new time-calibrated phylogeny (eight genes, 135 species). Integrating these data sets, we estimated evolutionary histories and diversification rates for each region, and tested correlations among species diversification, niche evolution, and niche divergence. Smilacaceae probably originated during the Late Cretaceous/Early Palaeocene and began to diversify in middle to low latitudes in Central America and Eurasia during the Late Eocene. Both the Old and New World clades exhibited a steady, albeit slight, increase of species diversification from the Late Eocene to Early Miocene. However, the Old World clade experienced an abrupt increase in net diversification during the Late Miocene. Our findings also revealed that species diversification rates were positively correlated with ecological niche evolution and niche divergence. Niche shifts and climatic niche evolution since the Middle Miocene played crucial roles in species diversification dynamics within Smilacaceae. The high plant richness in Asia may be explained by greater diversification in this region, potentially promoted by heterogeneous environments.

Key words: diversification, historical biogeography, macroevolution, niche evolution, phylogenetics, Smilacaceae