The evolution of phenotypic plasticity under global change.

Area of Science:

• Marine Biology
• Ecology
• Evolutionary Biology

Background:

• Marine ecosystems face unprecedented threats from ocean warming and acidification.
• Phenotypic plasticity enables populations to acclimate to environmental changes, potentially buffering global change impacts.
• The multi-generational evolution of phenotypic plasticity under global change remains poorly understood.

Purpose of the Study:

• To investigate how phenotypic plasticity evolves across multiple generations in response to ocean warming and acidification.
• To assess the adaptive capacity of marine organisms to combined global change stressors.
• To examine the eco-evolutionary implications of multi-generational plasticity for conservation.

Main Methods:

• Reciprocal transplantation of the polychaete Ophryotrocha labronica across control and global change scenarios (warming, acidification, combined) over five generations.
• Comparison of reaction norms for four life-history traits across generations.
• Analysis of selection pressures and individual fitness declines.

Main Results:

• Most traits maintained adaptive plasticity across generations despite significant selection and fitness declines.
• Juvenile developmental rate in the combined scenario was the only trait to alter its plastic response when returned to control conditions.
• Differential energy allocation is proposed as the mechanism for altered plasticity in the combined scenario.

Conclusions:

• Ophryotrocha labronica demonstrates conserved adaptive plasticity for most traits under multi-generational global change exposure.
• Altered plasticity in the combined scenario suggests complex eco-evolutionary dynamics.
• Maintaining within-generational plasticity is crucial for marine species survival and informs assisted evolution strategies.