Phylogenetic Comparative Methods - Applications

Applications

PCMs can be used to analyze the origin and maintenance of biodiversity. Biodiversity is most commonly discussed in terms of the number of species, but it can also be phrased in terms of the amount of phenotypic (e.g., physiological, morphological) space that a given set of species occupies (see also Cambrian explosion).

Phylogenetic comparative methods are commonly applied to such questions as:

• What is the slope of an allometric scaling relationship?

→ Example: how does brain mass vary in relation to body mass?

• Do different clades of organisms differ with respect to some phenotypic trait?

→ Example: do canids have larger hearts than felids?

• Do groups of species that share a behavioral or ecological feature (e.g., social system, diet) differ in average phenotype?

→ Example: do carnivores have larger home ranges than herbivores?

• What was the ancestral state of a trait?

→ Example: where did endothermy evolve in the lineage that led to mammals?

→ Example: where, when, and why did placentas and viviparity evolve?

• Does a trait exhibit significant phylogenetic signal in a particular group of organisms? Do certain types of traits tend to "follow phylogeny" more than others?

→ Example: are behavioral traits more labile during evolution?

• Do species differences in life history traits trade-off, as in the so-called fast-slow continuum?

→ Example: why do small-bodied species have shorter life spans than their larger relatives?