Journal article
Chromosome number evolves independently of genome size in a clade with nonlocalized centromeres (Carex: Cyperaceae)
Evolution, Vol.66(9), pp.2708-2722
09/2012
Handle:
https://hdl.handle.net/2376/116207
PMID: 22946798
Abstract
The effects of chromosome rearrangement on genome size are poorly understood. While chromosome duplications and deletions have predictable effects on genome size, chromosome fusion, fission, and translocation do not. In this study, we investigate genome size and chromosome number evolution in 87 species of Carex, one of the most species-rich genera of flowering plants and one that has undergone an exceptionally high rate of chromosome rearrangement. Using phylogenetic generalized least-squares regression, we find that the correlation between chromosome number and genome size in the genus grades from flat or weakly positive at fine phylogenetic scales to weakly negative at deeper phylogenetic scales. The rate of chromosome evolution exhibits a significant increase within a species-rich clade that arose approximately 5 million years ago. Genome size evolution, however, demonstrates a nearly constant rate across the entire tree. We hypothesize that this decoupling of genome size from chromosome number helps explain the high lability of chromosome number in the genus, as it reduces indirect selection on chromosome number.
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Details
- Title
- Chromosome number evolves independently of genome size in a clade with nonlocalized centromeres (Carex: Cyperaceae)
- Creators
- Kyong-Sook Chung - The Morton Arboretum, Illinois 60532-1293, USAAndrew L HippEric H Roalson
- Publication Details
- Evolution, Vol.66(9), pp.2708-2722
- Academic Unit
- Biological Sciences, School of
- Publisher
- United States
- Identifiers
- 99900548336101842
- Language
- English
- Resource Type
- Journal article