Evolutionary processes drive both morphological diversity in species and the generation of new species. There are places on the California landscape where these changes occur at a more rapid rate – evolutionary hot spots. Such places are likely to include: (1) bio-geographic suture zones, (2) areas with steep environmental gradients and/or high topographic or geologic complexity, and (3) areas subject to recent colonization and adaptive divergence or co-evolutionary selection pressures. Others will emerge with this study. Fossil evidence suggests that these hotspots will move across the landscape as climate changes; it is critical to better understand the processes generating the hotspots so we can develop conservation strategies that are more resilient to future climate change.

This research will predict the location of evolutionary hot spots at a geographic scale relevant to conservation planners. We will combine a conceptual model based on evolutionary theory with appropriate environmental layers to create a state-wide spatial surface that predicts relative evolutionary rates. For selected regions and taxa, we will evaluate and refine this prediction using available information on geographic patterns of species, phylogenetic and genetic diversity (see figure). This will entail collaboration with other research groups in the state who are generating comparative data on genetic and species diversity. From the November workshop, it was apparent that vertebrates (especially mammals, reptiles and amphibians) and some groups of insects and plants could be included in the initial analysis, allowing for analysis of spatial patterns of evolution across diverse organisms. Examples of areas that might exemplify evolutionary hotspots include the Santa Cruz and Santa Lucia Ranges, the mountains and adjacent lowlands of Southern California and area encompassing the southern Sierra Nevada – Tehachapi and adjacent lowlands. Within such areas, we will integrate the model and available biological evidence to produce fine scale maps of evolutionary hotspots and then evaluate priorities and options for acquisition in the context of existing protected areas.

Agencies entrusted with natural resource management, including restoration of habitats, tend to focus on wetlands, riparian areas, unique habitat and the continuing battle against invasive species. Identification of evolutionary hot spots provides a complementary way of looking at landscape values, focusing on the processes that generate diversity rather than just on the species and communities as they are today. Thus, we can both protect current biodiversity and the capacity of California’s natural areas to adapt to environmental change.

Museum of Vertebrate Zoology UC-Berkeley
Last modified on: 27 March 2006
Contact: Craig Moritz