Studies On DNA Molecular And Chromosomal Evolutions Of Lizards In China

Lizards is a major group of reptiles, which plays an important role in the evolution of the vertebrates. Studies on their evolution, especially the molecular and cytogenetical evolution, is of great significance to reveal the evolutionary history of reptiles and futherly that of all the vertebrates. Studies on DNA and chromosomal evolution of the representative kinds of lizards in China were performed using RAPD molecular marker and karyotype analysis in the present dissertation. The dissertation includes the following five parts:1. The studies and progress of molecular systematics on protein and DNA molecular level in reptiles were reviewed.2. The phylogenetic analysis using RAPD for 43 individuals of lizards distributed in 9 genus,4 family were carried out and generated the following results. 1) Agmidae is an old-age group oflizards of China. There is a high-level difference among three genus surveyed in the presentstudy. Scincidae and Gekkonidae are more evolutionary groups compared with Agmidae. Such aresult indicated that RAPD could be applied in phylogenetic analysis of taxa at genus and familylevel. 2) There is a close. relationship between Eremias and Lacerta. 3) There is a closerrelationship between Scincella tsinlingensis and S. modesta than that between 5. tsinlingensis andS. potanini. 4) In Gekkonidae, Cyrtodactylus is a basal branch of the phylogenetic trees,indicating that it is the most ancient among the three genus. Teratoscincus is less ancient,whereas Gekko is most evolutionary. G. gekko is the most ancient species with a high level ofdifferences with the other three species of Gekko, while there is a closer relationship betweenGekko hokouensis and G. swinhonis than that with G.japonicus; 5) There is a ctoser relationshipbetween Agama and Japalura, however their relationships with Phrynocephalus shown by thetwo kinds of phylogenetic trees were different. In the 10 species of Phrynocephalus, there is acloser relationship between P. vlangalii and P. forsythi than that between P. vlangalii and P.mystaceus in mid-Asian; P. axillaris and P. przewalskii constituted a sister group; P. frontalisand P. immaculatus are more evolutionary than the rest species; P. frontalis in the InnerMongolia should be reclassified as P. immaculatus. Intraspecific differentiation inPhrynocephalus was analyzed , and their origins and evolutionary routes were also documented.6) The application of different methods for reconstructing phylogenetic trees in systymatics werealso addressed based on the principles of these methods and the results of different methodsobtained in the present study.