Genome data analysis indicates that the major evolutionary transitions have been driven by substantial increases in genomic complexity. These increases, accounting for novelty in evolution, have proceeded mainly by gene duplication. This idea, advanced by <A HREF="#OHNO">Ohno (1968)</A>, remains current in the study of several organisms whose genomes have been sequenced. Maize, yeast, and humans contain more paralogons than would be expected to occur by chance, and this supports the contention that gene families were not formed de novo, but by large-scale DNA duplications. Lineage hybridization emerges as an efficient and widespread mechanism to create evolutionary novelty by recruiting redundant genes to new roles. Lateral gene transfer... |