Abstract:
The importance of recognizing patterns at different spatial scales is often overlooked in molecular ecological studies. The Antarctic and sub-Antarctic region presents a unique model for understanding genetic patterns at various spatial scales. At large spatial scales, understanding evolutionary patterns is often confounded by inaccurate taxonomy. A case in hand is the Amerenothroid mite group where molecular data highlight the need for a taxonomic revision for the group. The pattern for Azorella is also discussed where the different islands have very different genetic diversity patterns. At intermediate spatial scales (the scale of the island), patterns are complex as a results of heterogeneous landscapes and different climatic and glacial histories. Here I will focus on Marion Island as a model. The genetic patterns for various springtails, mites as well as a flightless moth will be compared and results placed within our current understanding of the history of the island. Finally, at small spatial scales local climatic conditions significantly affect gene flow. For this, the cushion plant Azorella selago serves as a model. There is a significant correlation between gene flow and the prevailing wind direction at four sites across Marion Island. The genetic neighborhood, or gene flow distance, is surprisingly small probably as a result of frequent rainfall events.
