Phylogeography of dune restricted insects in the desert Southwest

 

Island systems have been indispensable in understanding the processes generating biodiversity.  Examples from the Galapagos, Caribbean and Hawaiian archipelagos demonstrate the utility of islands for the study of adaptation, community assembly, and speciation. In addition to oceanic islands, habitat islands are also of great interest to evolutionary biologists.  Unlike oceanic islands, habitat islands are discrete patches of habitat surrounded by a contrasting habitat that is likely to change through time. Barriers between the different habitats may be more or less stringent for some taxa.  This is a notable difference, as the rules governing dispersal and vicariance may not be the same between oceanic and habitat islands.  A study of sand dunes, a habitat island system, in the desert southwest of North America will provide insight into the ways in which dispersal and vicariance operate in this unique island system.  To do this I propose to examine the comparative phylogeographic histories of three different insect groups.  My focal taxa include the giant flower loving flies Rhaphiomidas (Diptera), flightless sand treader crickets Macrobaenetes and Ammobaenetes (Orthoptera) and flightless weevils Trigonoscuta (Coleoptera).  I will present the current phylogenies for these taxa and their major biogeographic patterns.