About Karen D Crow



(415) 405-2760


Associate Professor


BiologyCollege of Science and Engineering


Hensill Hall (HH)



At SF State Since:



In FishLab, we use molecular approaches to understand the evolutionary forces that generate biological diversity, novelty, reproductive strategies and reproductive isolation in fishes. 

Much of our work focuses on Hox genes-a family of genes that specify body plan features. We are interested in understanding the role of the posterior HoxA and HoxD genes in the evolution and development of appendages and adornments that contribute to morphological diversity in fishes. We have found that Hox genes structure a variety of fin modifications, such as claspers in cartilagenous fishes, cephalic lobes in manta rays and their relatives, barbels in paddlefish, and the cloaca/vent in jawed vertebrates. We are currently looking at the role of Hox genes in the development of derived features in the Catalina goby, surfperches  and the evolution of male pregnancy in Syngnathids. We are also interested in the role duplicated Hox genes in paddlefish and teleosts, and the putative relationship between genome duplication and the evolution of complexity and diversity in vertebrates.  

While previous work has focused on questions varying in scale from paternity to genomics, including reproductive isolation, mechanisms of speciation, estimating phylogenetic relationships, and alternative life history strategies such as parental care, variation in courtship rituals, and sexual selection, the underlying theme is to understand the evolutionary processes that contribute to the evolution of novelty and diversity in fishes.