Environmental predictability in phylogenetic comparative analysis: how to measure it and does it matter?

Aim Abiotic environmental conditions shape ecological and evolutionary
processes, yet quantifying their influence on organisms remains
challenging due to variation among metrics and their intercorrelations.
This study evaluates the utility of temporal environmental predictability
measures and assesses their explanatory power in phylogenetic comparative
analyses. Innovation We systematically compare widely used metrics of
predictability and explore their correlations with environmental means and
variances in a global meteorological dataset. Using cooperative breeding
birds as a case study, we assess the impact of including predictability
metrics in phylogenetic comparative analyses. We demonstrate the
consequences of choosing specific metrics and the trade-offs between
increased data inclusion and model interpretability. Main conclusions
Predictability metrics, though intuitively meaningful, have been
conceptualised and quantified with diverse approaches. We found that
different measures of predictability can exhibit contrasting global
patterns and strong correlations with other environmental quantities.
Therefore, our findings caution against overloading statistical analyses
with correlated predictors, highlighting the need for a thoughtful
selection of environmental metrics to avoid spurious interpretations in
ecological and evolutionary studies.