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, 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, as well as the vent in ray-finned fishes, and barbels in paddlefish. We are currently looking at the role of Hox genes in the development of derived features in the Catalina goby, cephalic lobes in Mobulids, and dermal appendages 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.  

Other projects in FishLab include investigating the evolution of multiple embryos per egg capsule in rajid skates; and the evolution of plasticity in sex allocation in the simultaneous hermaphroditic gobies of the genus Lythrypnus, and most recently, the evolution of alternative reproductive strategies in the surfperches, Embiotocidae.

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.