Principles of niche expansion

Area of Science:

• Ecology
• Evolutionary Biology
• Theoretical Ecology

Background:

• Niche expansion is key to species adaptation and diversification.
• Existing theories, like the niche variation hypothesis, propose expansion via niche position variation, but this is debated.
• Alternative mechanisms for niche filling remain underexplored.

Purpose of the Study:

• To propose a general theory of niche expansion.
• To investigate the roles of resource diversity and acquisition trade-offs in niche evolution.
• To identify discrete pathways for niche filling.

Main Methods:

• Review of empirical data on niche expansion.
• Development and analysis of an eco-evolutionary model.
• Exploration of resource diversity and acquisition trade-off impacts.

Main Results:

• Niche expansion is constrained to two orthogonal strategies: phenotypical differentiation or individual generalization.
• A shift from individual generalization to phenotypical differentiation occurs when resource diversity is high and generalization is costly.
• These principles apply across evolutionary and short-term ecological timescales.

Conclusions:

• A unified theory of niche expansion is presented, driven by resource diversity and acquisition trade-offs.
• Environmental change dictates niche expansion through a principle of orthogonality between differentiation and generalization.
• The study reconciles empirical observations with theoretical predictions on niche evolution.