While skeletal evolution has been extensively studied, the evolution of limb muscles and brachial plexus has received less attention. In this review, we focus on the tempo and mode of evolution of forelimb muscles in the vertebrate history, and on the developmental mechanisms that have affected the evolution of their morphology. Tetrapod limb muscles develop from diffuse migrating cells derived from dermomyotomes, and the limb-innervating nerves lose their segmental patterns to form the brachial plexus distally. Despite such seemingly disorganized developmental processes, limb muscle homology has been highly conserved in tetrapod evolution, with the apparent exception of the mammalian diaphragm. The limb mesenchyme of lateral plate mesoderm likely plays a pivotal role in the subdivision of the myogenic cell population into individual muscles through the formation of interstitial muscle connective tissues. Interactions with tendons and motoneuron axons are involved in the early and late phases of limb muscle morphogenesis, respectively. The mechanism underlying the recurrent generation of limb muscle homology likely resides in these developmental processes, which should be studied from an evolutionary perspective in the future.

中文翻译：

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四足动物四肢肌肉系统的演变

虽然骨骼进化已被广泛研究，但四肢肌肉和臂丛神经的进化受到的关注较少。在这篇综述中，我们关注脊椎动物历史上前肢肌肉的发展速度和模式，以及影响其形态演变的发育机制。四足动物的四肢肌肉是由来自皮肤肌细胞的弥散性迁移细胞发育而来的，而四肢神经会失去其节段性模式，从而在远端形成臂丛神经。尽管看似杂乱无章的发育过程，但肢体肌肉同源性在四足动物的进化中一直高度保守，除了哺乳动物的diaphragm肌明显例外。通过形成间质性肌肉结缔组织，侧板中胚层的四肢间充质可能在成肌细胞群体细分为单个肌肉中起关键作用。与肌腱和运动神经元轴突的相互作用分别参与肢体肌肉形态发生的早期和晚期。肢体肌肉同源性再生的潜在机制可能存在于这些发育过程中，今后应从进化的角度进行研究。