ABSTRACT
This chapter begins by reviewing aspects of organismal genomes across the tree of life with a focus on eukaryotes followed by a discussion about key aspects concerning the molecular evolution of deoxyribonucleic acid (DNA) sequences. In a research project that aims to elucidate the evolutionary history of particular gene families, there is little or no ambiguity about which locus or loci will be the target for DNA sequence acquisition. The genomes of prokaryotes and organellar genomes usually exist as single circular double-stranded DNA molecules though some prokaryotes have genomes subdivided into multiple linear chromosome-like molecules. Located in the genomic spaces between RNA and protein-coding genes is a type of DNA collectively called intergenic DNA. The transposition of DNA elements in genomes is a form of site-specific or nonhomologous recombination. The process of primary integration of numts into eukaryotic genomes appears to be continuous over time.
