Disparate modes of evolution in chloroplast and nuclear genomes.

摘要

This thesis explores evolution of gene order in chloroplasts, genome duplications in flowering plants, and the relationship between phylogenetic position, polyploidy, and gene numbers. Comparisons of chloroplast gene orders in inferred ancestral and extant green algae and land plants, together with simulations under a neutral evolution model, indicate that gene order is under strong selection possibly resulting from an advantage for co-transcription of neighboring genes. We also show that genome duplications occurred in many lineages of flowering plants, and that basal angiosperm species express more genes in flowers than do derived eudicot and monocot species. The project illustrates how novel statistical approaches, applied to the rapidly growing database of expressed gene and genome sequences, can reveal mechanisms that underlie processes of genome evolution.