Episodic pulses in morphological diversification are a prominent feature of evolutionary history, driven by factors that remain widely disputed. Resolving this question has proved challenging because comprehensive species-level data are generally unavailable at sufficient scale. Combining global phylogenetic and morphological data for birds, we show that pulses of diversification in lineages and traits tend to occur independently and in different contexts. Speciation pulses are preceded by greater differentiation in overall morphology and habitat niche, then followed by increased rates of beak evolution. Contrary to standard hypotheses, pulses of morphological diversification tend to be associated with habitat niche stability rather than adaptation to different diets and habitat types. These patterns suggest that the timing of diversification varies across traits according to their ecological function, and that pulses of morphological evolution may occur when successful lineages subdivide niche space within particular habitat types. Our results highlight the growing potential of functional trait data sets to refine macroevolutionary models.

中文翻译：

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鸟类快速形态进化的原因及生态环境

形态多样化的偶发性脉冲是进化史的一个突出特征，其驱动因素仍然存在广泛争议。事实证明，解决这个问题具有挑战性，因为通常无法获得足够规模的全面的物种水平数据。结合鸟类的全球系统发育和形态学数据，我们表明谱系和性状的多样化脉冲往往在不同的背景下独立发生。物种形成脉冲之前是整体形态和栖息地生态位的更大分化，然后是喙进化率的增加。与标准假设相反，形态多样化的脉冲往往与栖息地生态位稳定性有关，而不是适应不同的饮食和栖息地类型。这些模式表明，多样化的时间因特征的生态功能而异，并且当成功的谱系细分特定栖息地类型中的生态位空间时，可能会出现形态进化的脉冲。我们的结果突出了功能性状数据集在改进宏观进化模型方面日益增长的潜力。