Biodiversity is distributed unevenly on the planet. Scientists have focused primarily on current climatic conditions as main drivers of diversity, while the importance of evolutionary processes has received less attention. The proposed research project aims to gain a better understanding of the role of evolutionary history in shaping current patterns of ant diversity in North America. The increased availability of molecular information allows a clearer understanding of evolutionary history and relationships among ant species. In turn this information can be used to examine the history of dispersal and colonization of populations over geological time scales. This work benefits from the availability of a large and newly compiled database on the distributions and diversity of ants, as well as the availability of a recently published phylogeny of ants, to gain new insights into the factors governing ant diversity. The proposed work entails collaboration with the Danish Center for Macroecology (DCM). The DCM is involved with Danish and International NGOs as well as with organizations such as UN/UNEP and the World Bank. Ecologists at the DCM also act as science advisors to the Danish parliament on issues relating to biodiversity and climate change. Therefore, the results of the proposed work will have impact beyond the scientific community in the US.