Dating the origins of polyploidy events
Article first published online: 16 DEC 2009
© The Authors (2009). Journal compilation © New Phytologist Trust (2009)
Special Issue: Plant polyploidy
Volume 186, Issue 1, pages 73–85, April 2010
How to Cite
Doyle, J. J. and Egan, A. N. (2010), Dating the origins of polyploidy events. New Phytologist, 186: 73–85. doi: 10.1111/j.1469-8137.2009.03118.x
- Issue published online: 3 MAR 2010
- Article first published online: 16 DEC 2009
- Received: 20 August 2009, Accepted: 18 October 2009
- disomic inheritance;
- divergence dating;
- homoeologue ages;
- tetrasomic inheritance
- •Polyploidy is a widespread speciation mechanism, particularly in plants. Estimating the time of origin of polyploid species is important for understanding issues such as gene loss and changes in regulation and expression among homoeologous copies that coexist in a single genome owing to polyploidy.
- •Polyploid species can originate in various ways; the effects of mode of origin, genetic system, and sampling on estimates of the age of polyploid origin using distances between alleles of polyploids and their diploid progenitors, or between homoeologous loci in a polyploid genome, are explored.
- •Even in the simplest cases, simulations confirm that different loci are expected to give very different estimates of the date of origin. The time of polyploid origin is at least as old as the time estimated from comparison of an allele sampled from the polyploid with the most closely related allele in the diploid progenitor. The polyploidy literature often does not make clear the longstanding observation that the divergence of homoeologous copies in an allopolyploid tracks the divergence of diploid species, not the origin of the polyploid.
- •Estimating the date of origin of a polyploid is difficult, and in some circumstances impossible. Skepticism about dates of polyploid origins is clearly warranted.