Table of Contents
International Journal of Evolutionary Biology
Volume 2012 (2012), Article ID 341932, 24 pages
Review Article

In with the Old, in with the New: The Promiscuity of the Duplication Process Engenders Diverse Pathways for Novel Gene Creation

Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA

Received 18 May 2012; Accepted 3 June 2012

Academic Editor: Frédéric Brunet

Copyright © 2012 Vaishali Katju. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The gene duplication process has exhibited far greater promiscuity in the creation of paralogs with novel exon-intron structures than anticipated even by Ohno. In this paper I explore the history of the field, from the neo-Darwinian synthesis through Ohno’s formulation of the canonical model for the evolution of gene duplicates and culminating in the present genomic era. I delineate the major tenets of Ohno’s model and discuss its failure to encapsulate the full complexity of the duplication process as revealed in the era of genomics. I discuss the diverse classes of paralogs originating from both DNA- and RNA-mediated duplication events and their evolutionary potential for assuming radically altered functions, as well as the degree to which they can function unconstrained from the pressure of gene conversion. Lastly, I explore theoretical population-genetic considerations of how the effective population size (Ne) of a species may influence the probability of emergence of genes with radically altered functions.