title: A unified model of autopolyploid establishment and evolution.
abstract: The prevalence of polyploidy among flowering plants is surprising given the hurdles impeding the establishment and persistence of novel polyploid lineages. In the absence of strong assortative mating, reproductive assurance, or large intrinsic fitness advantages, new polyploid lineages face almost certain extinction through minority cytotype exclusion. Consequently, much work has focused on a search for adaptive advantages associated with polyploidy such as increased competitive ability, enhanced ecological tolerances, and increased resistance to pathogens. Yet, no consistent adaptive advantages of polyploidy have been identified. Here, to investigate the potential for autopolyploid establishment and persistence in the absence of any intrinsic fitness advantages, we develop a simulation model of a diploid population that sporadically gives rise to novel autopolyploids. The autopolyploids have only very small levels of initial assortative mating or niche differentiation, generated entirely by dosage effects of genome duplication, and they have realistic levels of reproductive assurance. Our results show that by allowing assortative mating and competitive interactions to evolve, establishment of novel autopolyploid lineages becomes common. Additional scenarios where adaptive optima change over time reveal that rapid environmental change promotes the replacement of diploid lineages by their autopolyploid descendants. These results help to explain recent empirical findings that suggest that many contemporary polyploid lineages arose during the Cretaceous-Tertiary extinction, without invoking adaptive advantages of polyploidy.
authors.affiliation: Bioinformatics and Computational Biology, University of Idaho, Moscow, Idaho 83844, USA. bposwald@gmail.com
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Oswald
authors.forename: Scott L
authors.initials: SL
authors.lastname: Nuismer
mesh_terms: D005075:Biological Evolution; D004171:Diploidy; D004777:Environment; D031996:Heuchera / Q000235:genetics; D008954:Models, Biological; D029594:Onagraceae / Q000235:genetics; D010944:Plants / Q000235:genetics*; D011123:Polyploidy
references.citation: Nat Rev Genet. 2002 Apr;3(4):274-84
references.pmid: 11967552
references.citation: Proc Natl Acad Sci U S A. 1979 May;76(5):2480-4
references.pmid: 16592656
references.citation: Cell. 2007 Nov 2;131(3):452-62
references.pmid: 17981114
references.citation: Evolution. 2005 Sep;59(9):1867-75
references.pmid: 16261725
references.citation: New Phytol. 2010 Apr;186(1):5-17
references.pmid: 20070540
references.citation: Heredity (Edinb). 2007 Mar;98(3):143-50
references.pmid: 17091127
references.citation: Evolution. 1989 May;43(3):650-656
references.pmid: 28568380
references.citation: Evolution. 2005 Sep;59(9):1928-35
references.pmid: 16261730
references.citation: New Phytol. 2004 Mar;161(3):703-713
references.pmid: 33873724
references.citation: Annu Rev Genet. 2000;34:401-437
references.pmid: 11092833
references.citation: Evolution. 1999 Aug;53(4):1114-1127
references.pmid: 28565509
references.citation: Am J Bot. 2007 Sep;94(9):1527-33
references.pmid: 21636519
references.citation: New Phytol. 2007;175(4):764-772
references.pmid: 17688591
references.citation: Am Nat. 2007 Feb;169(2):227-44
references.pmid: 17211806
references.citation: New Phytol. 2000 May;146(2):281-290
references.pmid: 33862975
references.citation: New Phytol. 2005 Apr;166(1):5-8
references.pmid: 15760346
references.citation: Am Nat. 2001 Mar;157(3):245-61
references.pmid: 18707288
references.citation: Heredity (Edinb). 2005 May;94(5):538-46
references.pmid: 15770232
references.citation: Evolution. 2000 Aug;54(4):1182-91
references.pmid: 11005287
references.citation: Annu Rev Plant Biol. 2007;58:377-406
references.pmid: 17280525
references.citation: Science. 1994 Apr 15;264(5157):421-4
references.pmid: 17836906
references.citation: Proc Biol Sci. 2007 Oct 7;274(1624):2393-7
references.pmid: 17686733
references.citation: Evolution. 1985 Jan;39(1):41-52
references.pmid: 28563649
references.citation: Nature. 2004 Aug 19;430(7002):884-7
references.pmid: 15318220
references.citation: Am J Bot. 2005 Nov;92(11):1827-35
references.pmid: 21646100
references.citation: Proc Natl Acad Sci U S A. 2009 Aug 18;106(33):13875-9
references.pmid: 19667210
references.citation: Proc Natl Acad Sci U S A. 2009 Apr 7;106(14):5737-42
references.pmid: 19325131
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7051-7
references.pmid: 10860970
references.citation: Trends Genet. 2003 Mar;19(3):141-7
references.pmid: 12615008