Evolution in novel environments: Do restored prairie populations experience strong selection?

AbstractWhen populations colonize new habitats, they are likely to experience novel environmental conditions, and as a consequence may experience strong selection. While selection and the resulting evolutionary responses may have important implications for establishment success in colonizing populations, few studies have estimated selection in such scenarios. Here we examined evidence of selection in recently established plant populations in two prairie restorations in close proximity (< 15 km apart) using two approaches: 1) we tested for evidence of past selection on a suite of traits in two Chamaecrista fasciculata populations by comparing the restored populations to each other and their shared source population in common gardens to quantify evolutionary responses and 2) we measured selection in the field. We found evidence of past selection on flowering time, specific leaf area, and root nodule production in one of the populations, but detected contemporary selection on only one trait (plant height). This demonstrates that while selection can occur in colonizing populations, resulting in significant evolutionary responses in less than 6 generations, rapid evolutionary responses may be weak in even nearby populations sown with the same source population. Because contemporary measures of selection rarely predicted observed evolutionary responses, it also suggests that selection likely differs over the early stages of succession that characterize young prairies.

Download Full-text

Selecting landmarks in novel environments

PsycEXTRA Dataset ◽

10.1037/e520562012-486 ◽

2009 ◽

Author(s):

Jared E. Miller ◽

Laura A. Carlson

Keyword(s):

Novel Environments

Download Full-text

Faculty Opinions recommendation of Novel environments enhance the induction and maintenance of long-term potentiation in the dentate gyrus.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1020226.279662 ◽

2005 ◽

Author(s):

James Knierim

Keyword(s):

Dentate Gyrus ◽

Long Term Potentiation ◽

Term Potentiation ◽

Novel Environments

Download Full-text

Faculty Opinions recommendation of Novel environments enhance the induction and maintenance of long-term potentiation in the dentate gyrus.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1020226.232447 ◽

2004 ◽

Author(s):

James L. McGaugh

Keyword(s):

Dentate Gyrus ◽

Long Term Potentiation ◽

Term Potentiation ◽

Novel Environments

Download Full-text

Faculty Opinions recommendation of Rapid responses of soil microorganisms improve plant fitness in novel environments.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717978110.793470990 ◽

2013 ◽

Author(s):

Janneke Hille Ris Lambers

Keyword(s):

Soil Microorganisms ◽

Plant Fitness ◽

Rapid Responses ◽

Novel Environments

Download Full-text

Long-Term Experimental Evolution in Escherichia coli. IV. Targets of Selection and the Specificity of Adaptation

Genetics ◽

10.1093/genetics/143.1.15 ◽

1996 ◽

Vol 143 (1) ◽

pp. 15-26 ◽

Cited By ~ 23

Author(s):

Michael Travisano ◽

Richard E Lenski

Keyword(s):

Escherichia Coli ◽

Experimental Evolution ◽

Common Ancestor ◽

The Novel ◽

Physiological Mechanisms ◽

Outer Membranes ◽

Limiting Nutrient ◽

Novel Environments ◽

Uptake Mechanisms

Abstract This study investigates the physiological manifestation of adaptive evolutionary change in 12 replicate populations of Escherichia coli that were propagated for 2000 generations in a glucose-limited environment. Representative genotypes from each population were assayed for fitness relative to their common ancestor in the experimental glucose environment and in 11 novel single-nutrient environments. After 2000 generations, the 12 derived genotypes had diverged into at least six distinct phenotypic classes. The nutrients were classified into four groups based upon their uptake physiology. All 12 derived genotypes improved in fitness by similar amounts in the glucose environment, and this pattern of parallel fitness gains was also seen in those novel environments where the limiting nutrient shared uptake mechanisms with glucose. Fitness showed little or no consistent improvement, but much greater genetic variation, in novel environments where the limiting nutrient differed from glucose in its uptake mechanisms. This pattern of fitness variation in the novel nutrient environments suggests that the independently derived genotypes adapted to the glucose environment by similar, but not identical, changes in the physiological mechanisms for moving glucose across both the inner and outer membranes.

Download Full-text

Synteny Conservation and Chromosome Rearrangements During Mammalian Evolution

Genetics ◽

10.1093/genetics/147.1.289 ◽

1997 ◽

Vol 147 (1) ◽

pp. 289-296 ◽

Cited By ~ 2

Author(s):

Jason Ehrlich ◽

David Sankoff ◽

Joseph H Nadeau

Keyword(s):

Genome Analysis ◽

Systematic Errors ◽

Chromosome Rearrangements ◽

Mammalian Evolution ◽

Comparative Genome Analysis ◽

Reciprocal Translocations ◽

Comparative Genome ◽

Strong Selection ◽

Synteny Conservation

Abstract An important problem in comparative genome analysis has been defining reliable measures of synteny conservation. The published analytical measures of synteny conservation have limitations. Nonindependence of comparisons, conserved and disrupted syntenies that are as yet unidentified, and redundant rearrangements lead to systematic errors that tend to overestimate the degree of conservation. We recently derived methods to estimate the total number of conserved syntenies within the genome, counting both those that have already been described and those that remain to be discovered. With this method, we show that ~65% of the conserved syntenies have already been identified for humans and mice, that rates of synteny disruption vary ~25-fold among mammalian lineages, and that despite strong selection against reciprocal translocations, inter-chromosome rearrangements occurred approximately fourfold more often than inversions and other intra-chromosome rearrangements, at least for lineages leading to humans and mice.

Download Full-text

The Advantages of Segregation and the Evolution of Sex

Genetics ◽

10.1093/genetics/164.3.1099 ◽

2003 ◽

Vol 164 (3) ◽

pp. 1099-1118 ◽

Cited By ~ 12

Author(s):

Sarah P Otto

Keyword(s):

Sexual Reproduction ◽

Asexual Reproduction ◽

Deleterious Mutations ◽

Evolution Of Sex ◽

Beneficial Mutations ◽

Selection Regime ◽

Strong Selection ◽

Genome Wide ◽

Low Levels

AbstractIn diploids, sexual reproduction promotes both the segregation of alleles at the same locus and the recombination of alleles at different loci. This article is the first to investigate the possibility that sex might have evolved and been maintained to promote segregation, using a model that incorporates both a general selection regime and modifier alleles that alter an individual’s allocation to sexual vs. asexual reproduction. The fate of different modifier alleles was found to depend strongly on the strength of selection at fitness loci and on the presence of inbreeding among individuals undergoing sexual reproduction. When selection is weak and mating occurs randomly among sexually produced gametes, reductions in the occurrence of sex are favored, but the genome-wide strength of selection is extremely small. In contrast, when selection is weak and some inbreeding occurs among gametes, increased allocation to sexual reproduction is expected as long as deleterious mutations are partially recessive and/or beneficial mutations are partially dominant. Under strong selection, the conditions under which increased allocation to sex evolves are reversed. Because deleterious mutations are typically considered to be partially recessive and weakly selected and because most populations exhibit some degree of inbreeding, this model predicts that higher frequencies of sex would evolve and be maintained as a consequence of the effects of segregation. Even with low levels of inbreeding, selection is stronger on a modifier that promotes segregation than on a modifier that promotes recombination, suggesting that the benefits of segregation are more likely than the benefits of recombination to have driven the evolution of sexual reproduction in diploids.

Download Full-text