Cyclical Parthenogenesis and Viviparity in Aphids as Evolutionary Novelties
Article first published online: 29 MAY 2012
© 2012 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Special Issue: Perspectives on Evolutionary Novelty and Evo-Devo
Volume 318, Issue 6, pages 448–459, September 2012
How to Cite
2012. Cyclical parthenogenesis and viviparity in aphids as evolutionary novelties. J. Exp. Zool. 318B:448–459..
- Issue published online: 30 AUG 2012
- Article first published online: 29 MAY 2012
- Manuscript Accepted: 1 DEC 2011
- Manuscript Revised: 23 NOV 2011
- Manuscript Received: 14 MAY 2011
- Social Sciences and Humanities Research Council of Canada. Grant Number: 410-2008-0400
- National Science Foundation. Grant Number: IOS-1051643
Evolutionary novelties represent challenges to biologists, particularly those who would like to understand the developmental and genetic changes responsible for their appearance. Most modern aphids possess two apparent evolutionary novelties: cyclical parthenogenesis (a life cycle with both sexual and asexual phases) and viviparity (internal development and live birth of progeny) in their asexual phase. Here I discuss the evolution of these apparent novelties from a developmental standpoint. Although a full understanding of the evolution of cyclical parthenogenesis and viviparity in aphids can seem a daunting task, these complex transitions can at least be broken down into a handful of steps. I argue that these should include the following: a differentiation of two developmentally distinct oocytes; de novo synthesis of centrosomes and modification of meiosis during asexual oogenesis; a loss or bypass of any cell cycle arrest and changes in key developmental events during viviparous oogenesis; and a change in how mothers specify the sexual vs. asexual fates of their progeny. Grappling with the nature of such steps and the order in which they occurred ought to increase our understanding and reduce the apparent novelty of complex evolutionary transitions. J. Exp. Zool. (Mol. Dev. Evol.) 318B:448–459, 2012. © 2012 Wiley Periodicals, Inc.