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

• Applicant: Professor Dr. Lennart Olsson
• Subject Area: Evolution, Anthropology
• Term: from 2008 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 52486795

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.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Participating Person: Privatdozent Dr. Hendrik Müller