There is an immediate need to increase our understanding of the genetic basis for fitness differences in natural populations (Ellegren and Sheldon Nature 452:169-175, 2008). Fortunately, technological developments within genome research, notably the recent ability to retrieve massive amounts of DNA sequence data based on next generation sequencing , will make possible completely novel investigations of the link between genotypes and phenotypes in non-model organisms. With our background as major players in molecular ecology and evolutionary genomics of non-models for the last 15-20 years, we are excellently placed to take on a leading role in this process, developing a Next Generation Molecular Ecology . This research program will combine studies of candidate genes with large-scale gene expression analysis, several mapping approaches and comparative genomics to study the genetic basis of trait evolution in wild bird populations. First, we will search for and analyse loci involved with reproductive isolation and adaptive population divergence in a well-known system for speciation research the pied flycatcher and the collared flycatcher. A milestone of this program will be genome sequencing of the two flycatcher species. Second, we will track the genetic basis of behaviour using a unique breeding population of zebra finches and benefitting from the recently obtained genome sequence of this species. Third, we will identify the targets for adaptive evolution during avian evolution using comparative genomics. Overall, the program will be able to reveal the molecular genetic architecture behind phenotypic variation. The potential for scientific break-through in this interdisciplinary program should be significant.