Temporal variation in abiotic and biotic variables such as temperature, rainfall, food availability or predation pressure profoundly affects the abilities of organisms to survive and reproduce... Show moreTemporal variation in abiotic and biotic variables such as temperature, rainfall, food availability or predation pressure profoundly affects the abilities of organisms to survive and reproduce successfully. Most organisms are remarkably flexible in the face of such heterogeneity in habitat quality, and display phenotypic plasticity in response to environmental variation, i.e. the production of alternative phenotypes from a single genotype, dependent on the experienced environment. The aftrotropical butterfly Bicyclus anynana expresses alternative adult life histories in its habitat's wet and dry seasons, including reproductive timing and lifespan. This thesis aims to increase insight into the hormonal and transcriptional patterns that underlie life history plasticity in B. anynana. The first question is how the environment experienced during development induces the two adult seasonal forms via conserved hormonal pathways. The second major question covered in this thesis is what transcriptional changes in the adult are associated with the seasonal forms, and how ageing differs between the seasons. Together, these data contribute to a better mechanistic understanding of plastic responses as adaptation to environmental variation, and provide starting points for research into mechanisms linking development and ageing in humans, and how events during early development can affect lifespan and human health. Show less
