White Sands, New Mexico is a geologically young landscape of stark white dunes surrounded by dark desert scrubland. In three lizard species, there has been dramatic convergent adaptation to this feature; dune populations exhibit blanched coloration while adjacent populations are dark. This system provides a unique opportunity to better understand the conditions under which organisms adapt rapidly to changing environments and, ultimately, how new species evolve. An integrative approach will be employed to investigate adaptation in White Sands lizards. Molecular techniques will be used to study the relationship between gene flow and local adaptation and to identify specific genes involved in color evolution in reptiles. Field experiments will be conducted to study the relationship between ecology, reproductive biology and speciation.
This project contributes to understanding a central issue in biology, the evolution of biological diversity. Empirically, this study addresses an ongoing debate about the importance of ecological factors in speciation. Results are also relevant in formulating conservation policy. Focusing on conservation of landscapes represents a shifting paradigm toward preserving evolutionary processes rather than current species distribution patterns. Previous work has suggested that ecological transition zones are important for generating and maintaining biological diversity, and the proposed research will help evaluate the role of these areas as conservation targets.
