CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Chinese Academy of Sciences, Wuhan Botanical Garden, Wuhan 430074, Hubei, People's Republic of China.
Center of Conservation Biology, Chinese Academy of Sciences, Core Botanical Gardens, Wuhan 430074, People's Republic of China.
Proc Biol Sci. 2021 Nov 10;288(1962):20211575. doi: 10.1098/rspb.2021.1575. Epub 2021 Nov 3.
Evolutionary radiations have intrigued biologists for more than a century, yet our understanding of the drivers of radiating diversification is still limited. We investigate the roles of environmental and species-intrinsic factors in driving the rapid radiation of (Asteraceae) by deploying a number of palaeoenvironment-, diversity- and trait-dependent models, as well as ecological distribution data. We show that three main clades of began to diversify in the Miocene almost simultaneously, with increasing diversification rates (DRs) negatively dependent on palaeotemperature but not dependent on species diversity. Our trait-dependent models detect some adaptive morphological innovations associated with DR shifts, while indicating additional unobserved traits are also likely driving diversification. Accounting for ecological niche data, we further reveal that accelerations in DRs are correlated with niche breadth and the size of species' range. Our results point out a macroevolutionary scenario where both adaptive morphological evolution and ecological opportunities provided by palaeoenvironmental fluctuations triggered an exceptionally radiating diversification. Our study highlights the importance of integrating phylogenomic, morphological, ecological and model-based approaches to illustrate evolutionary dynamics of lineages in biodiversity hotspots.
演化辐射已经引起了生物学家一个多世纪的兴趣,但我们对推动辐射多样化的驱动因素的理解仍然有限。我们通过部署一系列依赖古环境、多样性和性状的模型以及生态分布数据,研究了环境和物种内在因素在推动(菊科)快速辐射中的作用。我们表明,三个主要的 分支在中新世几乎同时开始多样化,多样化速率(DR)与古温度呈负相关,但与物种多样性无关。我们的性状依赖模型检测到一些与 DR 转变相关的适应性形态创新,同时表明可能还有其他未观察到的性状也在推动多样化。考虑到生态位数据,我们进一步揭示了 DR 的加速与生态位宽度和物种范围的大小有关。我们的研究结果指出了一个宏观进化情景,即适应性形态进化和古环境波动提供的生态机会共同触发了一个异常辐射多样化的过程。我们的研究强调了整合系统基因组学、形态学、生态学和基于模型的方法来阐明生物多样性热点地区谱系进化动态的重要性。