Does a complex life cycle affect adaptation to environmental change? Genome-informed insights for characterizing...

Area of Science:

• Evolutionary biology
• Ecology
• Population genetics

Background:

• Complex life cycles, common in nature, involve distinct stages with different forms, functions, and ecological niches.
• Shared genomes across stages mean selection on one stage can impact the entire life cycle.
• Current research lacks clear predictions on how life cycle complexity affects adaptation to changing environments and fitness trade-offs across stages.

Purpose of the Study:

• To explore hypotheses for selection operating on organisms with complex life cycles.
• To propose a within-generation experimental design for studying composite selection across life stages.
• To determine the statistical power required for detecting selection across a life cycle using population genetic models.

Main Methods:

• Literature review on complex life cycle evolution.
• Development of three hypotheses: ontogenetic decoupling, antagonistic ontogenetic pleiotropy, and synergistic ontogenetic pleiotropy.
• Population genetic simulations to assess power for detecting selection across life stages.

Main Results:

• Simulations revealed that many recent studies on within-generation selection were underpowered to detect small allele frequency changes (approx. 0.1).
• The power analysis identified challenging but achievable sampling requirements for detecting selection across life cycles.
• Plants and marine invertebrates with high fecundity are identified as suitable systems for adaptation studies.

Conclusions:

• Understanding selection across complex life cycles is crucial for predicting evolutionary responses to environmental change.
• Future research requires robust experimental designs and adequate statistical power to detect subtle adaptive changes.
• Organisms with complex life cycles, particularly plants and marine invertebrates, offer valuable models for studying adaptation in the context of climate change.