Reconsidering the generation time hypothesis based on nuclear ribosomal ITS sequence comparisons in annual and perennial angiosperms
2008

Generation Time and Divergence Rates in Plants

Sample size: 16 publication 10 minutes Evidence: moderate

Author Information

Author(s): Soria-Hernanz David F, Fiz-Palacios Omar, Braverman John M, Hamilton Matthew B

Primary Institution: Georgetown University

Hypothesis

Differences in generation time between annual and perennial plants affect their rates of molecular evolution.

Conclusion

Annual plants often show faster substitution rates than perennial plants, but the differences are generally small.

Supporting Evidence

  • Annual plants exhibited faster rates of nucleotide substitution in most comparisons.
  • Rate differences were often less than 2-fold, suggesting a weak generation time effect.
  • Simulations indicated that relative rate tests have low power to detect small rate differences.

Takeaway

This study looked at how fast different plants change their DNA based on whether they live for one year or many years. It found that plants that live for one year usually change their DNA faster.

Methodology

The study compared nucleotide substitution rates using ITS sequences from 16 phylogenetically-independent annual/perennial species pairs.

Potential Biases

Potential phylogenetic bias due to the use of non-independent comparisons in previous studies.

Limitations

The study's conclusions may be limited by the low statistical power of the tests used, particularly for small rate differences.

Participant Demographics

The study included 16 species pairs of annual and perennial angiosperms.

Statistical Information

P-Value

p=0.017 for A. thaliana vs. A. lyrata; p=0.025 for A. thaliana vs. A. petraea

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1471-2148-8-344

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