A Müllerian mimicry ring in Appalachian millipedes

Abstract

Few biological phenomena provide such an elegant and straightforward example of evolution by natural selection as color mimicry among unrelated organisms. By mimicking the appearance of a heavily defended aposematic species, members of a second species gain protection from predators and, potentially, enhanced fitness. Mimicking a preexisting warning advertisement is economical because a potentially costly novel one can be avoided; simultaneously, the addition of more aposematic individuals enhances the overall warning effect. The better-known mimetic systems comprise tropical taxa, but here, we show a remarkable example of color mimicry in 7 species of blind, cyanide-generating millipedes endemic to the Appalachian Mountains of temperate North America. Because these millipedes lack eyes, there is no sexual selection or intraspecific signaling for coloration, providing an ideal system for mimicry studies. We document a Mü llerian symbiosis where unrelated species vary in color and pattern over geographical space but appear identical where they co-occur. By using spectral color data, estimations of evolutionary history, and detailed field observations of species abundance, we test 4 predictions of Mü llerian mimicry theory and begin to unravel the story of an elaborate mimetic diversification in the forests of Appalachia.aposematic ͉ reflectance ͉ Apheloriini ͉ Diplopoda ͉ Brachoria

Repeated evolution in overlapping mimicry rings among North American velvet ants

“…Müllerian mimicry rings have been described from a variety of North American taxa, including millipedes (seven species 6 ), eastern bumble bees (eight species 2 ) and the monarch and viceroy butterflies (two species 3 ), yet these mimetic systems often contain relatively few species. The butterfly genus Heliconius, which has become a model Müllerian system, contains 40 species, although other taxa are also involved with the Heliconius mimicry complexes.…”

“…Although Müllerian mimicry rings-groups of species that benefit from shared aposematic signals-have been documented from a variety of taxa, including reptiles, amphibians and arthropods (reviewed by Ruxton et al 2 ), the most well-known examples are lepidopteran (butterflies and moths) (for example, refs 3,4), with the Neotropical butterfly genus Heliconius among the most celebrated model systems 5 . Although Müllerian mimicry has been recognized in some Nearctic species 6 , species-rich mimicry rings are more often documented in tropical taxa. The apparent higher incidence of mimicry in the tropics has led to the postulation that mimicry might evolve more easily at lower latitudes due to higher predator and prey diversities 7 , but more studies on non-lepidopteran groups 2 and from non-tropical taxa are needed to better understand this phenomenon.…”

“…While structural morphological characters can often be used to distinguish each of these species, multiple geographically concordant colour forms are present within and among species. In other groups, including birds and butterflies, analyses have found that some of the similarities in supposed mimetic traits can be best explained by phylogenetic relatedness rather than through repeated or independent evolutionary events 6,25,26 . The goals of this paper are twofold: first, to describe morphological variation among female Dasymutilla velvet ants that potentially comprise multiple, overlapping mimicry rings; and second, to investigate the phylogenetic context in which mimetic phenotypes have evolved.…”

Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator

“…This has led to impressive morphological radiations in diverse taxonomic groups such as catfish 7 , millipedes 8 , snakes 9 , bees 10 , frogs 11 , moths 12 and, most famously, Heliconius butterflies 13 . In Heliconius, selection for Müllerian mimicry (mimicry between unpalatable species) has led to intraspecific divergence in wing patterns, as different populations radiate into distinct mimicry rings 13 .…”

Revisão taxonômica e análise cladística do gênero Odontopeltis Pocock, 1894 (Diplopoda, Polydesmida, Chelodesmidae)

“…7). Analisada em detalhe para Xystodesmidae por Marek & Bond (2009) Algumas poucas espécies de Chelodesmidae apresentam um par de projeções logo abaixo da abertura do gonopódio, no 7º segmento. Neste caso, o caráter se comporta de forma homoplástica, surgindo independentemente em…”