Meeting Abstract
100.3 Thursday, Jan. 7 Evolutionary reorganization of moth wing patterns towards a ‘dead leaf’ resemblance SUZUKI, Takao*; KURATANI, Shigeru; RIKEN CDB, Japan; RIKEN CDB, Japan tsuzuki@cdb.riken.jp
How an enormous organismal diversity and complexity could have evolved is a fundamental question of design principles of living organisms. As seen in vertebrate head skeleton evolution, the diversity of moth wing pattern can be generated by the inherited morphological parts. To avoid predators, it is probable that these parts are organized sufficiently to perform a requsite function. However, it has never been referred to how the pattern parts are integrated. Here, we reported the morphological design and evolutionary emergence of moth wing pattern mimicking a dead leaf.
As a model organism, we picked up a noctuid moth, Oraesia excavata, whose forewings have all the appearances of a detailed resemblance to a leafy pattern with one main and left-/right-sided leaf veins. By employing morphometrics, we found that the leafy pattern established a precise and modular organization: a lower variation against generic diffrences and the synchronizedly covariation concordant with leaf-vein features. To satisfy ecological requirements, these characteristics are likely to improve a camouflage strategy for an effective resemblance in a wild life. Furthermore, we found that when the leafy pattern evolved, a degree of integration within the pattern bands were restructured by changing the covariational structure. In addition, we investigated another noctuid moth, Thyas juno, which represents a different camouflage strategy. We found that unlike O. excavata, T. juno wing pattern posses a high degree of independency and almost no correlation among the pattern bands. It appears that more complex pattern evolved, more frequently the covariational structure was reorganized. Thus, the complex pattern was generated by an extremely flexible developmental system that allows successive changes of the pattern bands free from mutual constraints.
