Functional similarity, not phylogenetic relatedness, predicts the relative strength of competition

Abstract

Predicting the outcome and strength of species interactions is a central goal of community ecology. Researchers have proposed that outcomes of species interactions (competitive exclusion and coexistence) are a function of both phylogenetic relatedness and functional similarity. Studies relating phylogenetic distance to competition strength have shown conflicting results. Work investigating the role of phylogenetic relatedness and functional similarity in driving competitive outcomes has been limited in terms of the breadth of taxa and ecological contexts examined, which makes the generality of these studies unclear. Consequently, we gathered 1,748 pairwise competition effect sizes from 269 species and 424 unique species pairs with divergence times ranging from 1.14 to 1,275 million years and used meta-regression and model selection approaches to investigate the importance of phylogenetic relatedness and functional similarity to competition across ecological contexts. We revealed that functional similarity, but not phylogenetic relatedness, predicted the relative strength of interspecific competition (defined as the strength of interspecific competition relative to intraspecific competition). Further, we found that the presence of predators, certain habitats, increasing density of competitors, and decreasing spatial grain of experiments were all associated with more intense interspecific competition relative to intraspecific competition. Our results demonstrate that functional similarity, not phylogenetic relatedness, may explain patterns of competition-associated community assembly, highlighting the value of trait-based approaches in clarifying biotic assembly dynamics.

Determinants of synergistic cell-cell interactions in bacteria

“…Not finding a significant relationship between both parameters could be due to problems of the experimental setup. For example, an imbalanced or biased phylogenetic distribution of strains used to experimentally test this hypothesis could explain the inability to detect a significant statistical relationship (Horner-Devine and Bohannan 2006; Cadotte et al 2017;Mahon et al 2021). Alternatively, high rates of horizontal gene transfer within communities could erode the taxonomic specificity of synergistic interactions .…”

Nicho trófico y bioclimático de dos especies andinas cercanamente emparentadas de <i>Liolaemus </i>(Squamata, Liolaemidae) en el sur del Perú

“…De acuerdo con Darwin (1859) las especies filogenéticamente cercanas tienden a ser ecológicamente similares; por lo tanto, en algunas especies los nichos son rasgos conservativos. Sin embargo, pocas especies hermanas comparten nichos idénticos, ya que las similitudes ecológicas y filogenéticas a menudo no están relacionadas, por lo que no se puede suponer a priori que especies hermanas poseen semejanzas ecológicas (Wiens & Graham 2005, Losos 2008, Mahon et al 2021, Pelegrin et al 2021. Asimismo, los taxones hermanos podrían mostrar distintos grados de superposición de nichos en el espacio ecológico y geográfico.…”