Unearthing Modes of Climatic Adaptation in Underground Storage Organs Across Liliales.

The article focuses on testing adaptive hypotheses about the evolution of continuous traits, specifically climatic niche seasonality, in association with developmentally structured discrete traits, namely underground storage organs (USOs) in geophytic plants within the monocot order Liliales. Using a novel analytical pipeline that integrates hierarchical modeling of discrete morphological traits (via PARAMO) and adaptive evolution of continuous traits (via bayou), the study examines whether different types of USOs—modifications of leaf, stem, or root tissues—correlate with distinct climatic niches. The results indicate that, except for root tubers which are associated with lower temperature seasonality, plants with different USO types do not occupy significantly different climatic niches beyond what is expected by chance. This suggests that the developmental origin and tissue type of USOs may influence ecological relationships differently, challenging the notion of geophytism as a uniform adaptive strategy. The study also presents a flexible framework for future comparative analyses that accounts for complex trait hierarchies and imperfect correspondence between discrete and continuous trait evolution.