Renewed diversification is associated with new ecological opportunity in theNeotropical turtle ants

Abstract

Ecological opportunity, defined as access to new resources free from competitors, is thought to be a catalyst for the process of adaptive radiation. Much of what we know about ecological opportunity, and the larger process of adaptive radiation, is derived from vertebrate diversification on islands. Here, we examine lineage diversification in the turtle ants (Cephalotes), a species-rich group of ants that has diversified throughout the Neotropics. We show that crown group turtle ants originated during the Eocene (around 46 mya), coincident with global warming and the origin of many other clades. We also show a marked lineage-wide slowdown in diversification rates in the Miocene. Contrasting this overall pattern, a species group associated with the young and seasonally harsh Chacoan biogeographic region underwent a recent burst of diversification. Subsequent analyses also indicated that there is significant phylogenetic clustering within the Chacoan region and that speciation rates are highest there. Together, these findings suggest that recent ecological opportunity, from successful colonization of novel habitat, may have facilitated renewed turtle ant diversification. Our findings highlight a central role of ecological opportunity within a successful continental radiation.

The Phylogeny and Evolution of Ants

“…within some ant subfamilies (Schultz & Brady 2008;Ward et al 2010Ward et al , 2014Schmidt 2013;Brady et al 2014) and larger genera (Moreau 2008, Jansen et al 2010, Blaimer 2012, Branstetter 2012, Price et al 2014. These studies at shallower taxonomic levels have employed more extensive taxon sampling, which has enhanced inferences about diversification, biogeographic history, and trait evolution.…”

No ecological opportunity signal on a continental scale? Diversification and life-history evolution of African true toads (Anura: Bufonidae)

“…; Price et al. ). Conversely, a lack of signal has been attributed to the geographic and ecological complexity of continents, with ecological saturation unlikely to occur on such a scale (Derryberry et al.…”

“…, although not always; Price et al. ), even showing multiple EO events nested across subclades (Drummond et al. ; McGuire et al.…”

Ventosimonas gracilis gen. nov., sp. nov., a member of the Gammaproteobacteria isolated from Cephalotes varians ant guts representing a new family, Ventosimonadaceae fam. nov., within the order ‘Pseudomonadales’

“…Turtle ants (genus Cephalotes) represent a highly diverse and species-rich neotropical clade (Price et al, 2014). Studies using PCR amplification and DNA sequencing techniques have revealed that Cephalotes ants harbor a core gut microbiota (Anderson et al, 2012;Hu et al, 2014;Kautz et al, 2013;Russell et al, 2009).…”