Quantifying rates of evolutionary adaptation in response to ocean acidification

Area of Science:

• Marine Biology
• Evolutionary Biology
• Oceanography

Background:

• Ocean acidification poses a significant threat to marine biodiversity.
• Physiological impacts on growth, survival, reproduction, and immunology can alter species abundance and distribution.
• The capacity for evolutionary adaptation to ocean acidification is largely unquantified.

Purpose of the Study:

• To measure the potential for evolutionary response to ocean acidification in larval development rate.
• To compare the evolutionary potential of two coastal invertebrate species: the sea urchin (Strongylocentrotus franciscanus) and the mussel (Mytilus trossulus).

Main Methods:

• Utilized a full-factorial breeding design to assess larval development rate.
• Quantified phenotypic and genetic variation for larval size under future carbon dioxide (CO2) conditions.
• Incorporated demographic parameters like population turnover rates.

Main Results:

• The sea urchin (Strongylocentrotus franciscanus) exhibited significantly greater phenotypic and genetic variation for larval size compared to the mussel (Mytilus trossulus) under projected ocean acidification.
• Strongylocentrotus franciscanus demonstrated potential for faster evolutionary responses within 50 years, despite lower population turnover rates.

Conclusions:

• Genetic and phenotypic variation are critical indicators of evolutionary potential in response to environmental change.
• Sea urchins may adapt more readily to ocean acidification than mussels, suggesting differential resilience across species.
• Integrating genetic, phenotypic, and demographic data can predict species' evolutionary capacity to ocean acidification.