Abstract Detail

The evolutionary importance of polyploidy

Soltis, Douglas E. [1], Soltis, Pamela S. [2], Pennell, Matthew W. [3], Harmon, Luke J. [4], Tank, David [5].

Polyploidy, shifts in diversification and associated changes in characters in angiosperm evolution.

The strong framework and depth of coverage of the plant tree of life provides an important opportunity to elucidate features that have promoted angiosperm diversity. Polyploidy or genome doubling has been frequent in angiosperm history. Using a time-calibrated densely sampled phylogeny for angiosperms, it is possible to examine lineage diversification across the angiosperm tree of life and test the impact of whole-genome duplication (WGD) on angiosperm radiations. Across the angiosperms, nested shifts in diversification have resulted in an overall increased rate of net diversification and declining relative extinction rates through time. But, these shifts in diversification seldom correspond perfectly with WGD events. We found support, however, for the lag-time WGD radiation hypothesis, which suggests that increases in diversification follow closely behind WGD events. With this in mind, we can begin to search for key morphological traits that might be associated with these important diversification events. For example, at a deep scale, the mesangiosperm radiation (which yielded all angiosperms after the basalmost lineages) is associated with major morphological changes, including the evolution of congenitally sealed carpels, true vessel elements, and changes in perianth phyllotaxy and merosity. The eudicot radiation is associated with WGD as well as changes in chemistry and a major change in floral morphology. At shallower scales, WGD and diversification in Brassicales appears correlated with the chemical diversification in glucosinolates. Nodulation is associated with WGD and diversification in legumes. Other ancient WGDs and subsequent diversification events should be more closely examined to ascertain possible associated changes in morphological and chemical features, as well as to investigate the underlying genetic and genomic causes of these attributes.

1 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611, USA
2 - University Of Florida, Florida Museum Of Natural History, PO Box 117800, Gainesville, FL, 32611-7800, USA, 352/273-1964
3 - University of Idaho, Department of Biological Sciences, Moscow, ID, 83844, USA
4 - University of Idaho, Biological Sciences, Moscow, ID, 83844, USA
5 - University Of Idaho, Peabody Museum Of Natural History, 875 Perimeter Dr MS 3051, Moscow, ID, 83844-3051, USA

Keywords:
Polyploidy
Diversification
angiosperms
character evolution.

Presentation Type: Symposium Presentation
Session: SY19
Location: Salon 4/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 3:45 PM
Number: SY19006
Abstract ID:712
Candidate for Awards:None