Phylogenetic correlograms and the evolution of body size in South American owls (Strigiformes)

Abstract

During the last few years, many models have been proposed to link microevolutionary processes to macroevolutionary patterns, defined by comparative data analysis. Among these, Brownian motion and Ornstein-Uhlenbeck (O-U) processes have been used to model, respectively, genetic drift or directional selection and stabilizing selection. These models produce different curves of pairwise variance between species against time since divergence, in such a way that different profiles appear in phylogenetic correlograms. We analyzed variation in body length among 19 species of South American owls, by means of phylogenetic correlograms constructed using Moran's I coefficient in four distance classes. Phylogeny among species was based on DNA hybridization. The observed correlogram was then compared with 500 correlograms obtained by simulations of Brownian motion and O-U over the same phylogeny, using discriminant analysis. The observed correlogram indicates a phylogenetic gradient up to 45 mya, when coefficients tend to stabilize, and it is similar to the correlograms produced by the O-U process. This is expected when we consider that body size of organisms is correlated with many ecological and life-history traits and subjected to many constraints that can be modeled by the O-U process, which has been used to describe evolution under stabilizing selection.

Feeding ecology and phylogenetic structure of a complex neotropical termite assemblage, revealed by nitrogen stable isotope ratios

“…Related taxa usually tend to share biological traits, inherited from common ancestry. For example, closely related species of South American owls are closer in size than more distant species (Diniz-Filho & Sant'Ana, 2000). In a similar way, relatives generally tend to share ecological traits (Losos, 2008).…”

Predictive modeling for allopatricStrix(Strigiformes: Strigidae) owls in South America: determinants of their distributions and ecological niche-based processes

“…Beyond the actual phylogenetic affinities between South American Strix owls, we hypothesize that events in South America during the Cenozoic could have played a role in the speciation processes of this group. Speciation of South American Strix owls seems to have taken place after the late Miocene (9–8 mya; Sibley and Ahlquist , Diniz‐Filho and Sant'ana ). During the middle to late Miocene (17–11 mya), three successive Atlantic marine transgressions formed the “Paranean Sea” that spread over eastern Argentina, western Uruguay, southern Paraguay, and southeastern Bolivia (Ortiz‐Jaureguizar and Cladera ).…”