How and why to spot fly wings

摘要

How can different species evolve different physical features despite using similar molecular toolkits? Studies of wing colour development in fruitflies point to specific changes in a gene's regulatory region. Over the past two decades, comparative studies have shown that the development of even widely disparate organisms uses a surprisingly similar set of mechanisms. The process of development is controlled largelyby where and when key genes are switched on or off — events that are in turn determined by the binding of available proteins (transcription factors) to the genes' regulatory regions. From an evolutionary perspective, we need to know which of these developmental components have varied during evolution, providing the raw material that is sieved by natural selection to remould organisms. Identifying such components of change requires us to be able to link naturally occurring mutations closely to specific examples of morphological variability, both within species and between related species.