Spatial Selection and Local Adaptation Jointly Shape Life-History Evolution during Range Expansion.

Area of Science:

• Ecology and Evolutionary Biology
• Climate Change Biology
• Invasion Biology

Background:

• Species range shifts are accelerating due to climate change and invasions.
• Poleward expansions face joint selection pressures from spatial factors and local climate adaptation.
• Disentangling these evolutionary drivers is crucial for understanding biological assemblage changes.

Purpose of the Study:

• To differentiate the roles of spatial selection and local adaptation in life-history trait divergence during range shifts.
• To investigate evolutionary dynamics in the spider mite Tetranychus urticae during poleward expansion.
• To assess the combined influence of environmental gradients and spatial selection on evolutionary processes.

Main Methods:

• Integrated stochastic modeling with common garden experiment data.
• Utilized a highly parameterized individual-based model for spider mites (Tetranychus urticae).
• Linked empirical data with simulation outputs to infer evolutionary contributions.

Main Results:

• Both spatial selection and local adaptation significantly contributed to latitudinal life-history divergence.
• Spatial selection was the primary driver of variation in dispersal behavior.
• Local adaptation best explained variation in developmental rates.

Conclusions:

• Latitudinal life-history divergence in expanding species is jointly shaped by adaptation to environmental gradients and spatial selection.
• The integration of modeling and experiments offers a robust approach to studying evolutionary processes during range expansions.
• Understanding these dual evolutionary forces is key to predicting ecological responses to climate change and invasions.