Developmental and evolutionary implications of cold shock effects in the speckled wood butterfly
The effects of pupal cold shock on the life cycle and wing morphology of the Speckled Wood butterfly are examined and their genetic assimilation is investigated. Metamorphosis is modelled in terms of changes in stability, and the mediation of cold shock effects by hormones is considered. Current theories of pattern formation are evaluated for the species, and pattern is analysed using manual, photographic and digital methods. The development of wing morphology is modelled, and cold shock effects understood by comparison with normal development. Developmental canalisation is estimated as variability and fluctuating asymmetry. An index is developed that predicts the extent of assimilation. Likely modes of inheritance are suggested, and the possibility of natural cold shock and assimilation in the species is considered. Recent trends in biology indicate that neo-Darwinian concepts cannot adequately account for certain developmental and hereditary phenomena and that a new paradigm is emerging. The two schools are compared with particular reference to Weismann and Waddington, and the phenomenology is re-examined in the light of the new findings.