As an example: one macroecological metric is the “root distance”: basically, the number of nodes separating a species from the root of a phylogenetic tree. Several studies have looked at mean root distances among species within regions, classify species as basal (few nodes between root and tip) and derived (lots of nodes between root and tip). Under this classification scheme, there are very interesting differences in species richness between basal and derived taxa.
I have a hard time getting over my initial visceral reaction to the use of ‘basal’ versus ‘derived’ in this context (see previous discussion on the “coffee shop phylogenetics” series). While I think these studies are on to something, my take on root-node distances is that they are a metric of diversification rate or total diversification. Regions with more “derived” species thus contain more species from clades that have undergone substantial diversification (and hence, have greater root-tip nodal distances). But I think a focus on basal and derived taxa is confusing and this literature could benefit from eliminating the use of these terms in association with extant taxa (see, for example, Crisp and Cook on this subject).