Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland.
Departamento de Ecologia, Universidade Federal de Goiás, Campus Samambaia, Goiânia, Goiás, Brazil.
Proc Biol Sci. 2023 Apr 26;290(1997):20221793. doi: 10.1098/rspb.2022.1793. Epub 2023 Apr 19.
How traits affect speciation is a long-standing question in evolution. We investigate whether speciation rates are affected by the traits themselves or by the rates of their evolution, in hummingbirds, a clade with great variation in speciation rates, morphology and ecological niches. Further, we test two opposing hypotheses, postulating that speciation rates are promoted by trait conservatism or, alternatively, by trait divergence. To address these questions, we analyse morphological (body mass and bill length) and niche traits (temperature and precipitation position and breadth, and mid-elevation), using a variety of methods to estimate speciation rates and correlate them with traits and their evolutionary rates. When it comes to the traits, we find faster speciation in smaller hummingbirds with shorter bills, living at higher elevations and experiencing greater temperature ranges. As for the trait evolutionary rates, we find that speciation increases with rates of divergence in the niche traits, but not in the morphological traits. Together, these results reveal the interplay of mechanisms through which different traits and their evolutionary rates (conservatism or divergence) influence the origination of hummingbird diversity.
特征如何影响物种形成是进化生物学中长期存在的问题。我们研究了在蜂鸟中，物种形成率是否受到特征本身或其进化率的影响，蜂鸟在物种形成率、形态和生态位方面具有很大的变异性。此外，我们检验了两种对立的假设，假设物种形成率是由特征保守性还是特征分歧性来促进的。为了解决这些问题，我们分析了形态（体重和喙长）和生态位特征（温度和降水位置和宽度，以及中海拔），使用各种方法来估计物种形成率，并将其与特征及其进化率相关联。就特征而言，我们发现体型较小、喙较短、生活在较高海拔和经历较大温度范围的蜂鸟的物种形成速度更快。至于特征进化率，我们发现生态位特征的分歧率与物种形成率的增加有关，但形态特征则不然。总之，这些结果揭示了不同特征及其进化率（保守性或分歧性）通过何种机制相互作用影响蜂鸟多样性的起源。
