Rapid evolution of highly variable competitive abilities in a key phytoplankton species

Area of Science:

• Marine biology
• Evolutionary biology
• Climate change science

Background:

• Climate change poses significant challenges to marine plankton communities.
• Evolutionary adaptation is a potential mechanism for plankton to cope with environmental stressors.
• Understanding the transferability of laboratory-evolved adaptations to natural environments is crucial.

Purpose of the Study:

• To investigate if laboratory-induced adaptation in phytoplankton enhances fitness in natural plankton communities.
• To assess the role of pleiotropic effects in mediating fitness gains from adaptation.
• To examine the rate and variability of genotypic evolution under stress.

Main Methods:

• Experimental evolution of the phytoplankton species Emiliania huxleyi under controlled laboratory conditions.
• Assessing the fitness of evolved strains in competition experiments within natural plankton communities.
• Genomic analysis to identify evolved genotypes and their competitive abilities.

Main Results:

• Fitness advantages gained through laboratory adaptation were diminished or masked in natural communities.
• Pleiotropic effects were identified as a key factor limiting the expression of evolved fitness benefits.
• New Emiliania huxleyi genotypes evolved rapidly, exhibiting a wide range of competitive abilities.

Conclusions:

• Laboratory adaptation does not always translate to equivalent fitness benefits in complex natural environments.
• Pleiotropy significantly constrains the adaptive potential of phytoplankton facing climate change.
• Phytoplankton can evolve new genotypes with variable competitive traits on timescales relevant to climate change.