The fields of ecology and evolution have been linked since Darwin proposed natural selection as the mechanism by which ecological processes drive evolutionary change through adaptation. Nonetheless, a degree of independence between ecology and evolution has historically been justified by the assumption that evolution occurs on a timescale that is much too slow to be relevant to ecological dynamics. Numerous recent examples of rapid evolutionary change, however, have called this fundamental assumption into question. ACE scientists take advantage of recent technological advances in high-throughput nucleotide sequencing to study genetic variation in natural systems and focus on the following questions: What is the genomic basis of ecologically relevant traits? How do genetic diversity and the architecture of ecologically relevant traits affect the interactions between species and between species and a changing environment?