Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, 29071-Málaga, Spain.
Dinosaur Institute, Natural History Museum of Los Angeles County; Exposition Boulevard, Los Angeles, CA 90007, USA.
Biol Lett. 2022 Apr;18(4):20220047. doi: 10.1098/rsbl.2022.0047. Epub 2022 Apr 6.
Convergent evolution is a central concept in evolutionary theory but the underlying mechanism has been largely debated since . Previous hypotheses predict that developmental constraints make some morphologies more likely to arise than others and natural selection discards those of the lowest fitness. However, the quantification of the role and strength of natural selection and developmental constraint in shaping convergent phenotypes on macroevolutionary timescales is challenging because the information regarding performance and development is not directly available. Accordingly, current knowledge of how embryonic development and natural selection drive phenotypic evolution in vertebrates has been extended from studies performed at short temporal scales. We propose here the organization of the tetrapod body-axis as a model system to investigate the developmental origins of convergent evolution over hundreds of millions of years. The quantification of the primary developmental mechanisms driving body-axis organization (i.e. somitogenesis, homeotic effects and differential growth) can be inferred from vertebral counts, and recent techniques of three-dimensional computational biomechanics have the necessary potential to reveal organismal performance even in fossil forms. The combination of both approaches offers a novel and robust methodological framework to test competing hypotheses on the functional and developmental drivers of phenotypic evolution and evolutionary convergence.
趋同进化是进化理论的一个核心概念，但自 以来，其潜在机制一直存在很大争议。先前的假说预测，发育约束使某些形态比其他形态更容易出现，而自然选择则淘汰那些适应性最低的形态。然而，量化自然选择和发育约束在塑造宏观进化时间尺度上的趋同表型的作用和强度具有挑战性，因为有关性能和发育的信息无法直接获得。因此，从短期时间尺度上进行的研究中扩展了关于胚胎发育和自然选择如何驱动脊椎动物表型进化的现有知识。我们在这里提出将四足动物体轴的组织作为一个模型系统，以研究数亿年来趋同进化的发育起源。推动体轴组织的主要发育机制（即体节发生、同源异形效应和差异生长）的定量可以从椎骨计数中推断出来，而最近的三维计算生物力学技术具有揭示生物体性能的必要潜力，即使是在化石形式中也是如此。这两种方法的结合提供了一个新颖而强大的方法学框架，可用于测试关于表型进化和进化趋同的功能和发育驱动因素的竞争假说。
