Saurav Baral

1 Introduction Speciation and morphological diversification have shaped the remarkable diversity of life forms. The causes and consequences of selective agents and processes that drive this diversification are critical in structuring biological diversity. Research in this area was historically disconnected to a degree. Traits within a species were studied largely through the lens of selection and local adaptation (Darwin 1859; Gould and Lewontin 1979; Sheppard 1958; Wallace 1897).

Abstract Origins of phenotypic novelty represent a paradox. Maintenance of distinct, canalized morphs usually requires a complex array of polymorphisms, whose co-retention requires a genetic architecture resistant to recombination, involving inversions and master regulators.

Abstract doublesex regulates early embryonic sex differentiation in holometabolous insects, along with the development of species-, sex-, and morph-specific adaptations during pupal stages. How does a highly conserved gene with a critical developmental role also remain functionally dynamic enough to gain ecologically important adaptations that are divergent in sister species?