Radiations of mycalesine butterflies and opening up their exploration of morphospace.
The African butterfly Bicyclus anynana is an emerging model in evo-devo and eco-evo-devo. Much has been learned about the development, genetics, and evolution of wing eyespot patterns and about how seasonal polyphenism in this species provides an adaptive response to the wet-dry environments it inhabits. Recent work is also examining the role of male secondary sexual traits, the wing scent brushes, and associated sex pheromones in mate choice and sexual selection. However, B. anynana is but one member of a spectacular radiation amounting to some 250 extant species in the subtribe Mycalesina in the Old World tropics. Therefore, it is appropriate timing to consider whether the experimental work on a single species can help in analyzing pattern and process in the spectacular expansion of this whole clade of mycalesine butterflies. The most recent molecular phylogenetics (Kodandaramaiah et al. 2010 ) underpins the occurrence of several parallel geographical radiations on the African mainland, on Madagascar, and in Asia. Expansions of the mycalesine butterflies into more seasonal environments may have occurred in tandem with those of their larval host plants, the grasses, around 25 million years ago. This article examines how the findings from multidisciplinary work on B. anynana could be the basis for a comparative approach to unravel the processes of adaptation and speciation that have yielded patterns of occupancy of trait space in the mycalesines. The parallel nature of radiations in at least three geographical regions provides exceptional power for such an analysis. I argue that research on B. anynana has provided an invaluable backbone for such an endeavor by revealing candidate suites of traits involved in adaptation to new ecological opportunities and in the evolution of reproductive isolation.
Institute of Biology, Leiden University, 2300 RA Leiden, The Netherlands. pb499@cam.ac.uk
Paul M
PM
Brakefield
D000222:Adaptation, Physiological / Q000235:genetics; D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning; D002080:Butterflies / Q000033:anatomy & histology / Q000235:genetics*; D017753:Ecosystem; D005260:Female; D007814:Larva; D008297:Male; D015394:Molecular Structure; D010675:Pheromones / Q000737:chemistry / Q000378:metabolism; D010860:Pigments, Biological; D012727:Sex Characteristics; D014921:Wings, Animal / Q000033:anatomy & histology
D010675:Pheromones; D010860:Pigments, Biological