Trait and plasticity evolution under competition and mutualism in evolving pairwise yeast communities.

Area of Science:

• Evolutionary Biology
• Ecology
• Microbial Ecology

Background:

• Phenotypic plasticity evolution is well-understood for abiotic factors but less so for biotic interactions.
• Biotic interactions, such as competition and mutualism, are crucial drivers of evolutionary change.
• Understanding how these interactions shape trait evolution and plasticity is key to predicting ecological dynamics.

Purpose of the Study:

• To experimentally investigate the effects of competition and mutualism on trait and plasticity evolution in brewer's yeast.
• To quantify evolutionary changes in growth rate and resource use efficiency (RUE) under different biotic conditions.
• To compare the evolutionary trajectories of yeast strains evolving alone, with a competitor, and with a mutualist.

Main Methods:

• Utilized genetically modified brewer's yeast in pairwise experimental communities.
• Quantified evolutionary changes in growth rate, RUE, and their plasticity.
• Compared evolved strains to ancestral strains under controlled conditions.

Main Results:

• Strains evolving alone showed decreased RUE and RUE plasticity, with a tradeoff between growth rate and efficiency.
• Competition led to higher growth rates, lower RUE, and a stronger growth-efficiency tradeoff.
• Mutualism resulted in lower growth rates, higher RUE, and a weaker tradeoff, with little impact on plasticity evolution for either interaction.

Conclusions:

• Biotic interactions significantly influence the evolution of growth rate and RUE in yeast.
• Competition and mutualism impose different selective pressures, leading to distinct evolutionary outcomes.
• Abiotic factors may play a more substantial role than biotic interactions in driving the evolution of phenotypic plasticity.