Contrasting impacts of competition on ecological and social trait evolution in songbirds

Abstract

Competition between closely related species has long been viewed as a powerful selective force that drives trait diversification, thereby generating phenotypic diversity over macroevolutionary timescales. However, although the impact of interspecific competition has been documented in a handful of iconic insular radiations, most previous studies have focused on traits involved in resource use, and few have examined the role of competition across large, continental radiations. Thus, the extent to which broad-scale patterns of phenotypic diversity are shaped by competition remain largely unclear, particularly for social traits. Here, we estimate the effect of competition between interacting lineages by applying new phylogenetic models that account for such interactions to an exceptionally complete dataset of resource-use traits and social signaling traits for the entire radiation of tanagers (Aves, Thraupidae), the largest family of songbirds. We find that interspecific competition strongly influences the evolution of traits involved in resource use, with a weaker effect on plumage signals, and very little effect on song. Our results provide compelling evidence that interspecific exploitative competition contributes to ecological trait diversification among coexisting species, even in a large continental radiation. In comparison, signal traits mediating mate choice and social competition seem to diversify under different evolutionary models, including rapid diversification in the allopatric stage of speciation.

Phylogenomics of monitor lizards and the role of competition in dictating body size disparity

“…Conceptual work by Nuismer and Harmon (2015) led to the development of the Matching Competition (MC ) model by Drury et al (2016), which infers an interaction parameter (S) dictating attraction towards or repulsion from the mean trait value of interacting lineages. This was extended by Drury et al (2018b) to incorporate interactions matrices which limited interactions to only codistributed species. We build upon this framework by expanding the biogeographic information to include temporally and spatially dynamic ranges for ancestral taxa (inferred from rase, example in Fig.S6).…”

“…The concept of competition as an impetus for evolution however, has been difficult to show explicitly from the fossil or phylogenetic record, and has been criticized for an unnecessarily "progressive" view of the process of evolution (Benton 1987). With the recent development of more appropriate process-generating models, we are now capable of better testing the influence of lineage interactions on evolutionary outcomes (Drury et al 2016(Drury et al , 2018bManceau et al 2017;Quintero and Landis 480 2019). In the case of monitor lizards, the exaggerated disparity in body sizes of Australian species is best described by an evolutionary model which accounts for competition among taxa in both space and time.…”

Correlates of rate heterogeneity in avian ecomorphological traits

“…Drury et al . ). Antagonistic interactions between species can accelerate trait evolution if lineages rapidly differentiate in key traits to avoid competition (Grant & Grant ).…”

“…In contrast, biotic interactions have received much attention, particularly as drivers of rate variation in ecomorphological traits (e.g. Drury et al 2018). Antagonistic interactions between species can accelerate trait evolution if lineages rapidly differentiate in key traits to avoid competition (Grant & Grant 2006).…”

Detecting the macroevolutionary signal of species interactions

“…In this model, competition depends on the phenotypic similarity of coexisting species, so patterns predicted by the model are different from both early-burst models and models where rates of evolution depend on the number of coexisting species (Manceau, Lambert, & Morlon, 2016). The next step is to evaluate whether such models will provide a good fit across additional data sets (Drury et al, 2016(Drury et al, , 2018Hutchinson, Gaiarsa, & Stouffer, 2018). However, this general approach provides a way to connect coevolutionary models and comparative data (Clarke, Thomas, & Freckleton, 2017;Manceau et al, 2016).…”