title: Conserved patterns of integrated developmental plasticity in a group of polyphenic tropical butterflies.
abstract: Developmental plasticity is thought to have profound macro-evolutionary effects, for example, by increasing the probability of establishment in new environments and subsequent divergence into independently evolving lineages. In contrast to plasticity optimized for individual traits, phenotypic integration, which enables a concerted response of plastic traits to environmental variability, may affect the rate of local adaptation by constraining independent responses of traits to selection. Using a comparative framework, this study explores the evolution of reaction norms for a variety of life history and morphological traits across five related species of mycalesine butterflies from the Old World tropics.
  
  
  
  Our data indicate that an integrated response of a suite of key traits is shared amongst these species. Interestingly, the traits that make up the functional suite are all known to be regulated by ecdysteroid signalling in Bicyclus anynana, one of the species included in this study, suggesting the same underlying hormonal regulator may be conserved within this group of polyphenic butterflies. We also detect developmental thresholds for the expression of alternative morphs.
  
  
  
  The phenotypic plasticity of a broad suite of morphological and life history traits is integrated and shared among species from three geographically independent lineages of mycalesine butterflies, despite considerable periods of independent evolution and exposure to disparate environments. At the same time, we have detected examples of evolutionary change where independent traits show different patterns of reaction norms. We argue that the expression of more robust phenotypes may occur by shifting developmental thresholds beyond the boundaries of the typical environmental variation.
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK. erikvanbergen.science@gmail.com.|Present Address: Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, P-2780, Oeiras, Portugal. erikvanbergen.science@gmail.com.
authors.forename: Erik
authors.identifier: 0000-0002-9648-9837
authors.initials: E
authors.lastname: van Bergen
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
authors.forename: Dave
authors.initials: D
authors.lastname: Osbaldeston
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.|School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, CET campus, Trivandrum, 695016, India.
authors.forename: Ullasa
authors.initials: U
authors.lastname: Kodandaramaiah
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
authors.forename: Oskar
authors.initials: O
authors.lastname: Brattström
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.|Present Address: Department of Biology, City College of New York, City University of New York, Convent Avenue at 138th Street, New York, NY, 10031, USA.
authors.forename: Kwaku
authors.initials: K
authors.lastname: Aduse-Poku
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Brakefield
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D049628:Body Size; D002080:Butterflies / Q000033:anatomy & histology* / Q000737:chemistry / Q000235:genetics / Q000254:growth & development*; D004777:Environment; D005260:Female; D008018:Life Cycle Stages; D008297:Male; D014921:Wings, Animal / Q000033:anatomy & histology*
keywords: Bicyclus anynana; Developmental plasticity; Life-history evolution; Mycalesine butterflies; Reaction norm; Seasonal polyphenism