The take-off of research in 1930-1950s Edinburgh.

The fruit fly, , is a simple and powerful model organism. It has played a critical role over more than a century, for example in establishing the field of genetics, and in foundational insights into the molecular basis of development. From the 1930s until today, researchers at the University of Edinburgh have used to tackle questions in basic and biomedical science. Here the history of the initial decades of this research is explored, beginning with the introduction of research to Edinburgh by Francis Albert Eley Crew, in the newly established Institute of Animal Genetics. This period of research includes the discovery that chemicals can cause genetic mutation. This was demonstrated by research of the effects of mustard gas on flies by Charlotte Auerbach and colleagues, guided by the future Nobel laureate Hermann Muller. research was also formative in Conrad Hal Waddington's conceptual thinking about developmental biology, including in his vision of the epigenetic landscape. This holistic, systems-level view of the control of development was far before its time and has continued to be influential to this day in our conceptualisation of developmental biology and in the increasingly important field of systems biology. Waddington's experiments with in Edinburgh also gave rise to the evolutionary concept of genetic assimilation, in which an environmentally induced phenotype subsequently becomes genetically encoded.