Can a Network Approach Resolve How Adaptive vs Nonadaptive Plasticity Impacts Evolutionary Trajectories?

Area of Science:

• Evolutionary biology
• Developmental biology
• Genetics

Background:

• Plasticity's role in adaptation to novel environments is established, but a unifying mechanistic framework is lacking.
• Existing research highlights both adaptive and non-adaptive plasticity's contribution to evolution.
• Understanding network changes across evolutionary timescales is crucial for predicting plasticity's impact.

Purpose of the Study:

• To propose a mechanistic framework for predicting the conditions under which adaptive and non-adaptive plasticity dominate evolutionary processes.
• To elucidate how transcriptional, protein, and developmental networks influence phenotypic variation and adaptive evolution.
• To integrate developmental and evolutionary timescales for a comprehensive understanding of the genotype-phenotype map.

Main Methods:

• The study proposes a theoretical framework based on hierarchical network properties.
• It examines how buffering mechanisms within networks generate and maintain phenotypic variation.
• Predictions are derived regarding the influence of plasticity on adaptive evolution over different time scales.

Main Results:

• Buffering networks release cryptic genetic variation upon environmental change, facilitating rapid initial adaptation.
• Early adaptation involves selection acting on both adaptive and non-adaptive phenotypes.
• Longer-term evolutionary change focuses on compensatory mechanisms to restore robust development and integrated phenotypes.

Conclusions:

• A mechanistic framework requires understanding hierarchical network responses across developmental and evolutionary time.
• Plasticity's influence on adaptive evolution is mediated by network properties that buffer variation and respond flexibly to environments.
• This approach enhances the predictive power of evolutionary studies by linking genotype to phenotype through network dynamics.