Evolutionary Assembly of Communities in Butterfly Mimicry Rings

Abstract

Species co-occurrence in ecological communities is thought to be influenced by multiple ecological and evolutionary processes, especially colonization and competition. However, effects of other interspecific interactions and evolutionary relationships are less explored. We examined evolutionary histories of community members and roles of mutualistic and parasitic interactions (Müllerian and Batesian mimicry, respectively) in the assembly of mimetic butterfly communities called mimicry rings in tropical forests of the Western Ghats, India. We found that Müllerian mimics were phylogenetically clustered, sharing aposematic signals due to common ancestry. On the other hand, Batesian mimics joined mimicry rings through convergent evolution and random phylogenetic assembly. Since the Western Ghats are a habitat island, we compared species diversity and composition in its mimicry rings with those of habitat mainland to test effects of biogeographic connectivity. The Western Ghats consisted of fewer mimicry rings and an overall smaller number of aposematic species and mimics compared to habitat mainland. The depauperate mimicry rings in the Western Ghats could have resulted from stochastic processes, reflecting their long temporal and spatial isolation and trickling colonization by the mimetic butterfly communities. These results highlight how evolutionary history, biogeographic isolation, and stochastic colonization influence the evolutionary assembly and diversity of ecological communities.

What's in a band? The function of the color and banding pattern of the Banded Swallowtail

“…Both the color and the band of this butterfly may help it form a mimicry ring with other local species that share similar traits (Joshi, Prakash, & Kunte, ; Mallet & Gilbert, ). Other species of palatable Papilio butterflies are known Batesian mimics of unpalatable, aposematic butterflies (Chai, ; Kunte, ).…”

Evolution of ontogenic change in color defenses of swallowtail butterflies

“…While the color phenotypes of lineages at different lifestages were determined by the lifestage vulnerability and the visual and phytochemical backgrounds of lifestages, the broad evolutionary pattern may be influenced by several macroecological factors such as the latitudinal diversity gradient, environmental filters, and community dynamics that are known to influence the evolution of functional traits, such as color defenses (Elias & Joron, ; Joshi, Prakash, & Kunte, ; Kraft, Cornwell, Webb, & Ackerly, ; Losos, ). The widespread incidence of aposematism and crypsis across tropical and temperate lineages experiencing distinct environments indicates a limited role of phylogenetic constraint, geography, and macroevolutionary processes.…”

Evolutionary dynamics of mimetic rings in heterogeneous ecological communities

“…On the other hand, if habitats are more homogeneous, selection imposed by habitat may favor similar warning signals, leading to similar color patterns. In fact, the formation of multiple mimetic rings is more common in heterogeneous tropical than in homogeneous temperate zones (Sheppard et al, 1985;Beccaloni, 1997;Joshi et al, 2017). Second, our analyses showed that selective pressure exerted by the cooccurrence of other unpalatable species is enough for the emergence of distinct mimetic rings in a community, if the unpalatable species are specialized in the same habitat.…”

“…We already know that palatable mimics, i.e. Batesian mimics, rapidly converge towards the color trait pattern of species they co-occur (Joshi et al, 2017) and also influence the evolution of the mimetic rings (Franks & Noble, 2004). Therefore, we suggest that future works should investigate what are the effects of including Batesian mimics in a heterogeneous community for the formation of mimicry rings.…”

“…In fact, similar phenotypic patterns in Müllerian mimicry is mainly due to selection favoring convergence in color patterns (Joron & Mallet, 1998;Mallet, 1999), although trait similarity in some mimetic species may be due to multiple evolutionary processes (Merrill et al, 2015), including shared evolutionary history Joshi et al, 2017) and introgression of genes associated with the color patterns in closed-related species (Pardo-Diaz et al, 2012). Empirical and theoretical studies corroborate the notion that convergence among unpalatable species in a community should emerge because of selection, forming mimetic rings, in which multiple unpalatable species show the same color pattern (Benson, 1972;Kapan, 2001;Pinheiro, 2003;Beatty et al, 2004;Elias et al, 2008).…”