Skip to Main Content
Multilocus analyses reveal little evidence for lineage-wide adaptive evolution within major clades of soft pines (Pinus subgenus Strobus)Author(s): Andrew J. Eckert; Andrew D. Bower; Kathleen D. Jermstad; Jill L. Wegrzyn; Brian J. Knaus; John V. Syring; David B. Neale
Source: Molecular Ecology 22: 5635-5650
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
View PDF (0 B)
DescriptionEstimates from molecular data for the fraction of new nonsynonymous mutations that are adaptive vary strongly across plant species. Much of this variation is due to differences in life history strategies as they influence the effective population size (Ne). Ample variation for these estimates, however, remains even when comparisons are made across species with similar values of Ne. An open question thus remains as to why the large disparity for estimates of adaptive evolution exists among plant species. Here, we have estimated the distribution of deleterious fitness effects (DFE) and the fraction of adaptive nonsynonymous substitutions (alpha) for 11 species of soft pines (subgenus Strobus) using DNA sequence data from 167 orthologous nuclear gene fragments. Most newly arising nonsynonymous mutations were inferred to be so strongly deleterious that they would rarely become fixed. Little evidence for long-term adaptive evolution was detected, as all 11 estimates for a were not significantly different from zero. Nucleotide diversity at synonymous sites, moreover, was strongly correlated with attributes of the DFE across species, thus illustrating a strong consistency with the expectations from the Nearly Neutral Theory of molecular evolution. Application of these patterns to genome-wide expectations for these species, however, was difficult as the loci chosen for the analysis were a biased set of conserved loci, which greatly influenced the estimates of the DFE and alpha. This implies that genome-wide parameter estimates will need truly genome-wide data, so that many of the existing patterns documented previously for forest trees (e.g. little evidence for signature of selection) may need revision.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationEckert, Andrew J.; Bower, Andrew D.; Jermstad, Kathleen D.; Wegrzyn, Jill L.; Knaus, Brian J.; Syring, John V.; Neale, David B. 2013. Multilocus analyses reveal little evidence for lineage-wide adaptive evolution within major clades of soft pines (Pinus subgenus Strobus). Mol. Ecol. (22) 5635-5650.
Keywordsadaptive evolution, distribution of deleterious fitness effects, purifying selection, nearly neutral theory of molecular evolution
- Genetic Divergence and signatures of natural election in marginal populations of a Keystone, long-lived conifer, Eastern White Pine (Pinus strobus) from Northern Ontario
- Duplicated genes evolve independently in allopolyploid cotton.
- Demographically idiosyncratic responses to climate change and rapid Pleistocene diversification of the walnut genus Juglans (Juglandaceae) revealed by whole-genome sequences
XML: View XML