The evolution of ontogenetic "decision-making" in the wood of a clade of tropical plants.

This article focuses on the relationship between ontogenetic diversity and functional diversity in wood development within the Pedilanthus clade of the genus Euphorbia, which includes both succulent shrubs and woody trees. By coding wood cell types as symbolic "letters" and sequences of these cells as "words," the study uses language and information theory methods to analyze developmental "decision-making" in vascular cambium-derived cells. Results show that woody species exhibit greater ontogenetic diversity—reflected in higher numbers of distinct cell sequences and greater complexity metrics such as Shannon entropy and Lempel–Ziv values—compared to succulent species, consistent with their broader functional demands for water conduction, storage, and mechanical support. The findings suggest that natural selection shapes non-stochastic, plastic developmental patterns in long-lived plants, with woody species evolving more complex cell differentiation sequences from a less complex succulent ancestor, highlighting wood as a valuable system for studying ontogeny and functional evolution in wild, long-lived organisms.