Related Experiment Videos
Rapid response to artificial selection on flower size in Phlox
1Section of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA. g.lendvai@mail.utexas.edu
Heredity
|April 15, 2003
Summary
Quantitative traits in Phlox drummondii evolve rapidly. Bi-directional selection experiments demonstrated a high capacity for rapid evolution of floral traits, challenging the notion of slow evolutionary change.
Area of Science:
- Evolutionary biology
- Plant sciences
- Quantitative genetics
Background:
- Quantitative traits are generally considered to evolve slowly over many generations.
- Understanding the pace of evolution in floral morphology is crucial for plant speciation.
Purpose of the Study:
- To experimentally test the rate of evolution for quantitative floral traits.
- To investigate the capacity for rapid evolutionary response to selection in Phlox drummondii.
Main Methods:
- Bi-directional selection was applied to corolla diameter in Phlox drummondii for three generations.
- Flower size, tube length, and stigma-anther proximity were monitored.
- Genetic correlations, realized heritability, and narrow-sense heritability were calculated.
Main Results:
- Realized heritability for flower size was high (0.83).
- The average per-generation response in corolla diameter was approximately 5%.
- Genetic correlations among floral traits were weak or non-significant.
Conclusions:
- Phlox drummondii exhibits a significant capacity for rapid evolutionary response to selection.
- Rapid evolution of floral traits is possible and may contribute to species differentiation.
- The study challenges the assumption of slow evolution for quantitative traits.