In my research I use molecular approaches to understand the evolutionary forces that generate biological diversity, novelty, and reproductive isolation in fishes.
My recent work has focused on a family of genes that specify body plan features-the Hox genes. Specifically I have focused on the molecular evolution of HoxA11 and HoxA13 in ray-finned fishes, Hox cluster duplication in teleosts, and the putative relationship between genome duplication and the evolution of complexity and diversity in vertebrates. Based on this work, I hypothesized that genome duplication may be an important factor in reduced probability of extinction. Other projects in my lab include investigating the role of duplicate genes in distally elongating fields such as the paddlefish rostrum and variation in dermal appendages of seahorses and sea dragons; the evolution of multiple embryos per egg capsule in skates of the genus Raja; and the evolution of plasticity in sex allocation in the simultaneous hermaphroditic gobies of the genus Lythrypnus.
In previous work, I have investigated questions varying in scale from paternity to genomics in ray-finned fishes, including genetic differentiation of sub-populations for conservation designation, and estimating phylogenetic relationships. I have looked at conflict between hybridization and the maintenance of species boundaries, genomic conflicts associated with mechanisms of speciation, and alternative life history strategies including parental care, variation in courtship rituals, sexual selection, and sex allocation in hermaphrodites to evaluate how these characteristics contribute to diversification.
While my research spans a range of topics, the underlying theme is to understand the evolutionary processes that contribute to the evolution of novelty and diversity.
Recent Publications & Presentations
Crow, Karen D., Christopher D. Smith, Jan-Fang Cheng, Günter P. Wagner and Chris T. Amemiya. 2012. An independent genome duplication inferred from Hox paralogs in the American paddlefish-a representative basal ray-finned fish and important comparative reference. Genome Biology and Evolution.
Jessica M. Maxfield, James L. Van Tassell, Colette M. St. Mary, Jean-Christophe Joyeux, Karen D. Crow. 2012. Extreme gender flexibility: Using a phylogenetic framework to infer the evolution of variation in sex allocation, phylogeography, and speciation in a genus of bidirectional sex changing fishes (Lythrypnus, Gobiidae). Molecular Phylogenetics and Evolution 64 (2012) 416–427.
Crow, Karen D., Hiroyuki Munehara, Giacomo Bernardi. 2010. Sympatric speciation in a genus of marine reef fishes. Molecular Ecology 19:10 2089-2105.
Crow, Karen D., Chris Amemiya, Jutta Roth and Günter P. Wagner. 2009. Hypermutability of HoxA13a and functional divergence from its paralog are associated with the origin of a novel developmental feature in zebrafish and related taxa (Cypriniformes). Evolution. 63(6): 1574-1592.
Crow, Karen D., Hiroyuki Munehara, Ziyusei Kanamoto, Andrey Balanov, Dmitriy Antonenko, and Giacomo Bernardi. 2007. Maintenance of species boundaries despite rampant hybridization between three species of reef fishes (Hexagrammidae): Implications for the role of selection. Biological Journal of the Linnean Society. 91: 135-147.
Crow, Karen D. and Günter P. Wagner. 2006. What is the role of genome duplication in the evolution of complexity and diversity in vertebrates? Molecular Biology and Evolution. 23(5): 887-892.
Crow, Karen D., Peter F. Stadler, Vincent J. Lynch, Chris Amemiya, and Günter P. Wagner. 2006. The “fish specific” Hox cluster duplication is coincident with the origin of teleosts. Molecular Biology and Evolution. 23(1): 121-136.
Metscher, B. D., K. Takahashi, K. D. Crow, C. Amemiya, D. F. Nonaka, and G. P. Wagner. 2005. Expression of Hoxa-11 and Hoxa-13 in the pectoral fin of a basal ray finned fish, Polyodon spathula: implications for the origin of tetrapod limbs. Evolution and Development. 7:186-195.
Crow, Karen D., Ziyusei Kanamoto and Giacomo Bernardi. 2004. Molecular phylogeny of the hexagrammid fishes using a multi-locus approach. Molecular Phylogenetics and Evolution. 32(3):986-997.
Balanov, A.A., A.I. Markevich, D.V. Antonenko, and K.D. Crow. 2001. The first occurrence of hybrids of Hexagrammos otakii, H. octogrammus and description of H. otakii (Hexagrammidae) from Peter the Great Bay (Sea of Japan).
Journal of Ichthyology. 41(9):28-738.
Nielsen, J.L., K.D. Crow and M.C. Fountain. 1999. Microsatellite diversity and conservation of a relic trout population: McCloud River redband trout.
Molecular Ecology. 8 (S12, Dec. 1999):129-142.
Crow, K.D., L. Barbieri and S. Lowerre-Barbieri. 1999. "Sex, Lies, and Audiotape" or Variation in diel periodicity of courtship sound production in spotted seatrout, Cynoscion nebulosus. Georgia Journal of Science. 57(2):143-144.
Crow, K.D., D.A. Powers and G. Bernardi. 1997. Evidence for multiple maternal contributors in nests of kelp greenling (Hexagrammos decagrammus, Hexagrammidae). Copeia. 1997(1):9-15.