Motivation It is well understood that natural variation is abundant within and between species. The neutral theory of molecular evolution suggested that the effect of most of mutations is so small that they can be considered as neutral. Recent evidence, however, demonstrated that a large proportion of natural variation seems to be of functional importance, possibly involved in adaptation to the environment. Powerful population genetics tools have been developed to identify genes under selection, but the functional validation of such ecologically important variants requires new functional approaches suitable to measure effects that are important in the wild, but difficult to score in the laboratory. Conversely, there is increasing evidence that natural variation in structural or regulatory genes have major effects, which were only recognized through the comparison of different naturally occurring variants. Drosophila is a perfectly suited model organism to further study the importance of natural variation. In addition to the availability of the genomic sequence of 12 species, there are also numerous activities of the Drosophila community to provide fully sequenced genomes of multiple individuals from natural populations. In combination with the sophisticated tools for functional analyses, D. melanogaster will serve a major role in deciphering the functional importance of natural variation. Research focus: evolutionary novelty and functional innovations Innovation is a key component of evolution and it can be observed at all taxonomic levels. Morphological innovations are most easily recognized in interspecific comparisons and have been the focus of many studies in EvoDevo. The adaptation of natural populations to their environment also provides a rich repertoire of functional innovations. We use a combined approach of functional genetics and statistical methods to identify and characterize intra- and inter-specific functional innovations.
