Selection for intermediate mortality and reproduction rates in a spatially structured population

Area of Science:

• Theoretical ecology
• Population dynamics
• Evolutionary dynamics

Background:

• Local interactions are crucial for understanding population and evolutionary dynamics.
• Disturbance events can significantly impact population persistence.
• The interplay between spatial structure, mobility, and disturbance is a key research area.

Purpose of the Study:

• To investigate how local interactions influence population and evolutionary dynamics under rare disturbance events.
• To compare dynamic behaviors of sessile versus mobile populations facing disturbances.
• To explore the evolutionary consequences of mutations on birth and mortality rates in different spatial structures.

Main Methods:

• Utilized a 'well-mixed' analytical model.
• Employed spatially explicit individual-based models.
• Simulated rare disturbance events with density-dependent propagation and mortality.

Main Results:

• Sessile populations with local offspring dispersal exhibit greater persistence against disturbances compared to mobile, well-mixed populations.
• Well-mixed populations consistently evolve towards extinction following a single disturbance event.
• For sessile populations, selection may favor traits like shorter lifespans and reduced offspring production.
• Evolving host characteristics and the rate of host variation introduction significantly influence population dynamics.

Conclusions:

• Spatial structure and individual mobility profoundly alter population and evolutionary trajectories under disturbance.
• Local dispersal in sessile populations enhances resilience to rare extinction events.
• Evolutionary processes, influenced by local interactions, can lead to adaptations that promote persistence but may involve trade-offs in life-history traits.