Thesis abstract:

«p»«p»«p»Despite viviparity evolving over 150 times within vertebrates, the molecular mechanisms underpinning the changes in biology during the transition from oviparity to viviparity are still largely unknown. The scincid lizards «em»Saiphos equalis«/em» and «em»Lerista bougainvillii«/em» are two of only three known vertebrates to display oviparity, viviparity, and an intermediate ‘transitional’ form of parity mode, worldwide. This situation makes these species ideal models to investigate these molecular mechanisms, without confounding effects of speciation.«/p» «p»This project will explore the phylogenetic relationship between different parity modes in both species. Building on this foundation I will determine population structure using reduced-representation sequencing in «em»L. bougainvillii«/em». These data will help answer whether transitional forms of parity mode are a result of a reversal or a potential hybridisation event, as well as determine the number of transitions to viviparity present in these two species. Additionally, I will explore changes in gene and protein expression in different parity modes and across stages of gravidity. This will identify the molecular changes that occur during evolution to support the internal incubation of embryos during development. The results of this study will inform broadly how complex traits, which are responsible for much of the diversity of life on Earth, evolve.«/p»«/p»«/p»