School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
School of Natural Science, University of Hull, Hull HU6 7RX, UK.
Sci Adv. 2023 Oct 27;9(43):eadg1641. doi: 10.1126/sciadv.adg1641. Epub 2023 Oct 25.
Widely documented, megaevolutionary jumps in phenotypic diversity continue to perplex researchers because it remains unclear whether these marked changes can emerge from microevolutionary processes. Here, we tackle this question using new approaches for modeling multivariate traits to evaluate the magnitude and distribution of elaboration and innovation in the evolution of bird beaks. We find that elaboration, evolution along the major axis of phenotypic change, is common at both macro- and megaevolutionary scales, whereas innovation, evolution away from the major axis of phenotypic change, is more prominent at megaevolutionary scales. The major axis of phenotypic change among species beak shapes at megaevolutionary scales is an emergent property of innovation across clades. Our analyses suggest that the reorientation of phenotypes via innovation is a ubiquitous route for divergence that can arise through gradual change alone, opening up further avenues for evolution to explore.
大量文献记录表明，表型多样性的大规模进化跳跃仍令研究人员感到困惑，因为目前尚不清楚这些显著的变化是否可以来自微观进化过程。在这里，我们使用新的方法来模拟多变量特征，以评估鸟类喙进化中精细化和创新的程度和分布，从而解决了这个问题。我们发现，精细化，即沿着表型变化的主要轴进行进化，在宏观和大进化尺度上都很常见，而创新，即远离表型变化的主要轴进行进化，在大进化尺度上更为明显。在大进化尺度上，物种喙形状的表型变化的主要轴是各进化枝之间创新的一个涌现特性。我们的分析表明，通过创新重新定向表型是一种普遍的分歧途径，它可以仅通过逐渐变化产生，为进化开辟了更多的探索途径。
