De Bello et al. contemplate the usefulness of phylogenetic corrections in ecological studies involving species traits. They conclude that it is necessary to consider phylogeny when focusing on the evolution of a trait as an adaptation to the environment, but unnecessary when assessing how the composition of traits across a community of species changes along an environmental gradient or under short-term environmental change.
Although I agree with their points, the ultimate aim is often to make predictions for new conditions. I therefore suggest putting more effort into exploring the mechanisms behind variation in trait values along environmental gradients.
Understanding which functional traits evolved as adaptations is thus a necessary baseline for predicting changes in species functional composition and ecosystem processes in the near future.