Kristina M. Sefc

 

 

 


Prof. Dr. Kristina M. Sefc

Department of Zoology
University of Graz
Universitätsplatz 2
A-8010 Graz
Tel. +43 (0) 316 380-5601
Fax +43 (0) 316 380-9875

kristina.sefc@uni-graz.at

 

 

Research

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Evolution shapes behavior, and behavior influences the course of evolution. I am interested in how behavior and evolutionary processes interact in various contexts including reproduction, migration and dispersal, ecological specialization and territoriality.
My recent work focusses on teleost fish of the familiy Cichlidae. The remarkable diversification of cichlid fishes is ascribed to their particular breeding biology and their capacity for ecological specialization. Sexual and natural selection shaped morphologies and behaviors, and in turn, the resultant phenotypes constrained, permitted or accelerated evolutionary changes.
One focus taxon, the genus Tropheus, occupies a narrow trophic niche in the rocky littoral of Lake Tanganyika, Africa. Being restricted to this particular type of habitat, species are divided into multiple separate populations along the lake shore, with little or no gene flow across even minor habitat barriers. This, in consequence, enabled the different populations to evolve specific color patterns and to produce one of the most stunning examples of intraspecific color pattern diversity. The territorial, sexually monomorphic Tropheus communicate by means of body color signals in both sexual and agonistic contexts, and sexual and social selection may have affected color pattern evolution. Allopatric color pattern diversification was in some cases, but not always, accompanied by the evolution of color-assortative mating preferences. Secondary contact among differentiated populations occurred in the course of lake level fluctuations, and a few of the extant color morphs are likely to have originated from hybridization during such population admixtures.
Our research addresses the evolutionary history of Tropheus populations, reproductive isolation among color morphs, social and sexual interactions within populations, hybrid origins of color morphs and the molecular basis of color pattern differentiation. Putting together evidence from these different approaches, we hope to identify the processes behind the rapid and extensive allopatric diversification.
 

Mating and breeding behaviors are highly diverse across cichlid species. Even within Lake Tanganyika, we find mouthbrooders and substrate breeders, uniparental, biparental and cooperative breeders, monogamous, polygynous, polyandrous and promiscuous species, as well as a diversity of alternative reproductive tactics such as piracy and sneaking. Genetic parentage of broods is often found to be at odds with the social mating system, and both intra- and interspecific brood adoption occur. Within a species, reproductive behavior may vary considerably across seasons or among populations. Reproductive strategies affect how individuals can maximize their own fitness, how reproductive success is distributed within populations, and how sexual selection influences the evolution of populations and species.
Our research investigates the true (genetic) parentage in cichlid broods in a background of different social mating systems, and is concerned with consequences on individual fitness and sexual selection.



A few recent publications:

Sefc K.M., Brown A.C., Clotfelter E.D. 2014. Carotenoid-based coloration in cichlid fishes. Comparative Biochemistry and Physiology Part A, 173, 42-51. pdf
Maan M.E., Sefc K.M. 2013. Colour variation in cichlid fish: proximate mechanisms, selective pressures and evolutionary consequences. Seminars in Cell & Developmental Biology, 24, 516-528. pdf
Zoppoth P., Koblmüller S., Sefc K.M. 2013. Male courtship preferences demonstrate discrimination against allopatric colour morphs in a cichlid fish. Journal of Evolutionary Biology, 26, 577-586. pdf
Sefc K.M. 2011. Mating and Parental Care in Lake Tanganyika's Cichlids. International Journal of Evolutionary Biology, vol. 2011, Article ID 470875, 20 pages, 2011. doi:10.4061/2011/470875. pdf