Morphological innovation, diversification and invasion of a new adaptive zone

Abstract

How ecological opportunity relates to diversification is a central question in evolutionary biology. However, there are few empirical examples of how ecological opportunity and morphological innovation open new adaptive zones, and promote diversification. We analyse data on diet, skull morphology and bite performance, and relate these traits to diversification rates throughout the evolutionary history of an ecologically diverse family of mammals (Chiroptera: Phyllostomidae). We found a significant increase in diversification rate driven by increased speciation at the most recent common ancestor of the predominantly frugivorous subfamily Stenodermatinae. The evolution of diet was associated with skull morphology, and morphology was tightly coupled with biting performance, linking phenotype to new niches through performance. Following the increase in speciation rate, the rate of morphological evolution slowed, while the rate of evolution in diet increased. This pattern suggests that morphology stabilized, and niches within the new adaptive zone of frugivory were filled rapidly, after the evolution of a new cranial phenotype that resulted in a certain level of mechanical efficiency. The tree-wide speciation rate increased non linearly with a more frugivorous diet, and was highest at measures of skull morphology associated with morphological extremes, including the most derived Stenodermatines. These results show that a novel stenodermatine skull phenotype played a central role in the evolution of frugivory and increasing speciation within phyllostomids.

The role of ecological opportunity in shaping disparate diversification trajectories in a bicontinental primate radiation

“…Evolution of the cranium, mandible and teeth is tightly correlated with diet owing to the functional requirements of processing food [35][36][37][38]. Therefore, I examine two components of feeding morphology to test the role of dietary adaptations on the diversification of colobine morphology: (i) mandible shape and (ii) the length, breadth and/or height of select cranio-mandibular dental (CMD) characters averaged for each species (electronic supplementary material, tables S1 and S2).…”

Roosting Ecology of Amazonian Bats: Evidence for Guild Structure in Hyperdiverse Mammalian Communities

“…Studies of phyllostomid adaptive radiation have hitherto focused exclusively on feeding behavior (e.g., Wetterer et al, 2000;Datzmann et al, 2010;Monteiro and Nogueira, 2011;Dumont et al, 2011;Rojas et al, 2011), resulting in scenarios that are sometimes accompanied by impressive analyses of trophic morphology. Although dietary adaptations have almost certainly played an important role in phyllostomid evolution, causal inferences in this literature would be strengthened if alternative behavioral traits that might also have influenced relevant evolutionary phenomena were considered.…”

“…For example, recent phylogenetic studies (Dumont Shi and Rabosky, 2015;Rojas et al, 2016) have detected a statistically significant diversification-rate shift at or near the base of the subfamily Stenodermatinae, a clade that comprises predominantly frugivorous species. Dumont et al (2011) attributed this rate shift, which resulted in a marked increase in lineage accumulation, to the evolution of new cranial phenotypes that improved frugivorous-feeding performance. However, frugivory is not the only derived behavioral trait shared by stenodermatines, which also include almost all the phyllostomid species known to roost in foliage, as well as all the phyllostomid species believed to modify leaves as tentlike shelters.…”

Phylogenetic fields of species: cross-species patterns of phylogenetic structure and geographical coexistence

“…This would allow them to occur at the same regions and coexist with closely and distantly related species, producing phylogenetic fields indistinguishable from range size variation alone. In fact, recent phylogenetic analyses suggest phenotypic and ecological stasis after early species' differentiation within Phyllostomidae followed by increasing speciation rates [44,51,52], which may account for the high number of closely related coexisting species. Finally, we cannot discard the potential effect of evolutionary range dynamics on current coexistence patterns [43,53], which may explain the lability and lack of phylogenetic signal in phyllostomid range sizes.…”