Plasticity leaves a phenotypic signature during local adaptation

Area of Science:

• Evolutionary Biology
• Plant Sciences
• Ecology

Background:

• Phenotypic responses to new environments are initially plastic, with genetic changes potentially following.
• The role of environmentally induced phenotypes in adaptive evolution is debated.
• Understanding the interplay between plasticity and genetic adaptation is crucial for predicting evolutionary trajectories.

Purpose of the Study:

• To test if phenotypic plasticity acts as an adaptive developmental bias, influencing local adaptation in plants.
• To investigate the alignment of plasticity, standing variation, and genetic divergence during local adaptation.
• To determine if genetic accommodation modifies plasticity during adaptation.

Main Methods:

• Analysis of multivariate data from 34 plant reciprocal transplant studies.
• Comparison of environmentally induced phenotypes with locally adapted phenotypes.
• Assessment of the relationship between plasticity, phenotypic variation, and genetic divergence.

Main Results:

• Phenotypic variation increased slightly in novel environments.
• The direction of ancestral plasticity generally aligned with the phenotypic differences in locally adapted populations, suggesting plasticity leads adaptation.
• While plastic responses could be extreme, induced and adapted phenotypes were rarely misaligned; genetic accommodation did not consistently alter plasticity.

Conclusions:

• Phenotypic plasticity is a significant source of developmental bias that shapes plant adaptation to environmental change.
• Plasticity influences the direction and magnitude of evolutionary adaptation, even when not directly constrained by selection.
• These findings highlight the persistent role of plasticity in evolutionary processes across changing environments.