Quality-quantity trade-offs drive functional trait evolution in a model microalgal 'climate change winner'

Area of Science:

• Ecology
• Evolutionary Biology
• Microbiology

Background:

• Phytoplankton form the base of aquatic ecosystems and are crucial for global nutrient cycles.
• Some phytoplankton taxa are predicted to increase in abundance due to climate change, termed 'climate change winners'.
• Understanding the evolution of these 'climate change winners' is vital for predicting future ecosystem dynamics.

Discussion:

• Microalgal populations were evolved in ameliorated environments for hundreds of generations to simulate persistent climate change.
• Populations evolved to allocate less carbon to growth and enhanced their capacity to metabolize reactive oxygen species (ROS).
• This trade-off between growth and ROS tolerance influences the ecological and biogeochemical functions of phytoplankton.

Key Insights:

• Evolutionary adaptation in phytoplankton involves a trade-off, prioritizing ROS tolerance over rapid growth.
• Metabolic and evolutionary frameworks can explain trait evolution in 'climate change winners'.
• Persistent environmental amelioration may dampen or reverse initial population increases in phytoplankton.

Outlook:

• Further research can explore the long-term consequences of these evolved traits on aquatic food webs.
• Investigating the genetic basis of ROS tolerance and altered carbon allocation in phytoplankton is warranted.
• These findings have implications for biogeochemical modeling and predicting the future of aquatic ecosystems under global change.