Plasticity and constraint in the evolution of development: Has the aquatic larval stage re-evolved in plethodontid salamanders?

多洛定律指出，复杂的结构一旦在进化过程中丢失，就不太可能以同样的形式重新获得。这一观点最近受到了严重的挑战，研究表明，一个水生幼虫从直接发育的祖先在plethodontid蝾螈的重新进化。虽然系统发育证据似乎令人信服，但我们目前对能够实现这种再进化的进化和发育机制知之甚少。我们提出的项目是一个plethodontid蝾螈的发展调查，研究plethodontids的直接发展的演变，并调查机制，导致其潜在的逆转。为此，将采用整体包埋免疫染色、共聚焦激光扫描显微镜、显微CT扫描、计算机3D重建等技术来研究头部骨骼和相关肌肉组织的发育，作为相关特征的特别丰富的来源。调查所涉及的发展过程，将进一步我们的发展中发挥的作用，调解进化多样化的理解。

Dollo s Law states that complex structures are unlikely to be regained in the same form, once they are lost during evolution. This notion has been seriously challenged recently by studies indicating a re-evolution of an aquatic larva from direct developing ancestors in plethodontid salamanders. While the phylogenetic evidence seems compelling, we have currently little understanding of the evolutionary and developmental mechanisms that would enable such a reevolution. The project we propose is an investigation of the development of plethodontid salamanders, to study the evolution of direct development in plethodontids and to investigate mechanisms leading to its potential reversal. To this end, whole-mount immunostaining, confocal laser scanning microscopy, micro-CT scanning, computerized 3D reconstruction and other techniques will be employed to investigate the development of the head skeleton and associated musculature, as a particularly rich source of relevant characters. Investigating the developmental processes involved will further our understanding of the role played by development in mediating evolutionary diversification in general.