Phylogenetic niche conservatism - common pitfalls and ways forward

Area of Science:

• Ecology
• Evolutionary Biology
• Biogeography

Background:

• The prevalence of phylogenetic niche conservatism (PNC) is a contentious topic in ecology and evolutionary biology.
• Disagreements stem from varied definitions and measurement approaches for PNC.
• Common PNC measures are sensitive to the assumptions of niche evolution models, yet this is often overlooked.

Purpose of the Study:

• To highlight the critical assumptions underlying simple phylogenetic niche conservatism measures.
• To demonstrate how violated assumptions can lead to misleading conclusions about PNC.
• To emphasize the necessity of rigorous assumption testing before applying PNC metrics.

Main Methods:

• Utilized simulations to illustrate the impact of violated niche evolution model assumptions on PNC.
• Evaluated the commonality of assumption violations in applied research.
• Stressed the need for in-depth pre-testing of model assumptions.

Main Results:

• Simple measures like phylogenetic signal and evolutionary rate are difficult to apply and interpret correctly.
• The assumption that strong phylogenetic signal directly indicates PNC is frequently invalid.
• Interpreting evolutionary rate for PNC requires comparative analyses and robust null models.

Conclusions:

• Accurate assessment of PNC necessitates comparing alternative evolutionary models, including flexible options like multiple-optima OU models.
• PNC can be indicated by few peak shifts or narrow adaptive landscapes in these advanced models.
• Evaluating the general prevalence of PNC requires studies adhering to high standards in defining PNC, testing assumptions, and employing sophisticated comparative models.