Eco-evolutionary feedback reshapes competitive dynamics in an orchard fly system

Area of Science:

• Ecology
• Evolutionary Biology
• Population Dynamics

Background:

• The interplay between competition and evolution is crucial for understanding species diversity origins and maintenance.
• It remains uncertain if competition-induced evolution is rapid and strong enough to sustain diversity over ecological timescales.

Purpose of the Study:

• To investigate the rapid, consistent, and strong evolutionary responses to interspecific competition.
• To determine if competition-induced evolution can maintain species diversity on ecological timescales.

Main Methods:

• An outdoor mesocosm experiment was designed using four pairs of orchard fly species.
• The species' capacity for reciprocal evolution during interspecific competition was manipulated.

Main Results:

• Significant and rapid evolution was observed across multiple phenotypes, often shifting in parallel among species.
• This rapid evolution substantially impacted the competitive population dynamics of all species pairs.
• The rarer species' abundance was typically increased, and in one instance, the abundance hierarchy was reversed.

Conclusions:

• The feedback loop between competition and evolution appears to be a common mechanism.
• This feedback likely plays a significant role in maintaining species diversity on ecological timescales.