The Mayer lab is currently wrapping up an investigation of possible hybrid speciation involving a group of the cholla cactus species of the local Anza-Borrego desert. The lab also has ongoing projects tackling the evolution and biogeography of a large group of wildflowers of the mustard family native to much of the New World. Broader aspects of this work involve collaborations with scientists at institutions in Missouri and Ontario, Canada, but the components involving smaller groups of Californian species are undertaken on campus with the help of USD students. To address these research questions, Mayer and his students generate and analyze data from sources that range from morphological to molecular, with a current emphasis on DNA fingerprinting and sequence approaches.