Tempo and mode of morphological evolution are decoupled from latitude in birds
Fig 2
Parameter estimates from single-regime models reveal varying impacts of latitude.
There is no impact of latitude on the effect of competition on trait evolution as measured by the slope of (a) DDexp models or (b) DDlin models. (c) The effect of competition on trait evolution as measured by the repulsion parameter (“S”) from the MC models increases with the index of tropicality (the proportion of species in the clade with exclusively tropical breeding distributions) for locomotion pPC3 but not for other traits. (d) There is no relationship between the proportion of taxa in a clade that breed in the tropics and the estimated rate of trait evolution from BM models. Solid lines represent statistically significant relationships (S6 and S13 Tables). For (a–c), each point represents the mean across clade-by-trait fits to stochastic maps of biogeography (for all families with at least 50 species), and for (d), each point represents the MLE for each clade-by-trait fit (see S2 and S3 Datas). BM, Brownian motion; DD, diversity-dependent; DDexp, exponential diversity-dependent; DDlin, linear diversity-dependent; MC, matching competition; MLE, maximum likelihood estimate; pPC, phylogenetic principal component.