Project groups


Project leader:
Prof. Dr. Axel Janke

The arctic has very dark, cold and long winters that are followed by short summers. Arctic environments thus provide some of the earth’s most harsh habitats for species to persist in. On the other hand, arctic habitats show very high productivity during the summer months, demonstrating that adequately adapted taxa can thrive in this extreme ecozone. Evolutionary studies have shown that most arctic species diverged from southern species during the Pleistocene (<2.5 million years) or Holocene (<12,000 years), i.e. they have adapted to arctic conditions over relatively short time frames. This time frame coincides with the Pleistocene climate cooling which led to the formation of the arctic ice sheets. However, this Pleistocene cooling period included numerous temperature fluctuations (warm and cold phases) that must have put a lot of stress on the adaptation to this environment, because arctic-adapted species could not migrate further north during phases of climate warming.

The current climate change is already manifesting itself in arctic habitats as permafrost thawing, decrease in extent and thickness of sea ice and coastal erosion. Today, many arctic species are therefore endangered, facing shrinking habitats and increased competition with boreal and temperate species.
Arctic vertebrates, such as the iconic polar bear (Ursus maritimus), are an ideal taxonomic group to study genomic effects of climate changes, because recent genome sequencing projects have provided abundant genomic data from other mammals for comparison. This facilitates both design of experiments and interpretation of results.

We are investigating the genomic effects and signatures of adaptation to life in the arctic using modern (”next-generation”) genomic techniques. Specifically, we are generating large amounts of sequence data from polar bears and their closest relative, brown bears (Ursus arctos). The latter has a widespread distribution in Palearctic and Nearctic habitats ranging from subarctic to subtropical zones, but is absent in high arctic habitats. Brown bears have likely been able to escape some of the harsh effects of the Pleistocene climatic fluctuations by shifting their distribution range north-/southwards. These differences in “adaptation” must have led to differences in the genetics of the species.
By comparing the genomes of this species pair, we are trying to find these differences in their genes and other genomic regions that evolved differently in these arctic and non-arctic species.



Aarnes, S.G., Hagen, S.B., Andreassen, R., Schregel, J., Knappskog, P.M., Hailer, F., Stenhouse , G., Janke, A., & H.G. Eiken (2015) : Y-chromosomal testing of brown bears (Ursus arctos): Validation of a multiplex PCR-approach for nine STRs suitable for fecal and hair samples. - Forensic Science International: Genetics

Ahlering, M.A., Hailer, F., Roberts, M.T. & C. Foley (2011) : A simple and accurate method to sex savannah, forest and Asian elephants using noninvasive sampling techniques. - Molecular Ecology Resources 11(5): 831–834.

Bapteste, E. and van Iersel, L. and Janke, A. and Kelchner, S. and Kelk, S. and McInerney, J.O. and Morrison, D.A. and Nakhleh, L. and Steel, M. and Stougie, L. and Whitfield, J.(2013) : Networks: expanding evolutionary thinking. - Trends in Genetics, 29 (8). pp. 439-441

Bidon, T., Janke, A., Fain, S. R., Eiken, H. G., Hagen, S. B. Saarma, U.,Hallström, B. M., Lecomte, N. & F. Hailer (2014) : Brown and Polar Bear Y Chromosomes Reveal Extensive Male-Biased Gene Flow within Brother Lineages. - Molecular Biology and Evolution (2014) 31 (6)

Bidon, T., Frosch, C., Eiken, H.G., Kutschera, V.E., Hagen, S.B., Aarnes, S.G., Fain, S.R., Janke, A. & F. Hailer (2013) : A sensitive and specific multiplex PCR approach for sex identification of ursine and tremarctine bears suitable for non-invasive samples. - Molecular Ecology Resources 13(3): 362-368.

Bidon, T., Schreck, N., Hailer, F., Nilsson, M., & A. Janke (2015) : Genome-wide search identifies 1.9 megabases from the polar bear Y chromosome for evolutionary analyses. - Genome Biology and Evolution

Bock, F., Gallus, S., Janke, A., Hailer, F., Steck, B.L., Kumar, V. & M. A. Nilsson (2014) : Genomic resources and genetic diversity of captive lesser kudu (Tragelaphus imberbis). - ZOO BIOLOGY 33: 440-445

Fennessy, J., Bidon, T., Reuss, F., Kumar, V., Elkan, P., Nilsson, M.A., Vamberger, M., Fritz, U. & A. Janke (2016) : Multi-locus Analyses Reveal Four Giraffe Species Instead of One. - Current Biology , doi:10.1016/j.cub.2016.07.036.

González-Porter, G.P., Maldonado, J.E., Flores-Villela, O., Vogt, R.C., Janke, A., Fleischer, R.C. & F. Hailer (2013) : Cryptic population structuring and the role of the Isthmus of Tehuantepec as a gene flow barrier in the critically endangered Central American River Turtle. - PLoS ONE 8(9): e71668.

Hailer, F., Kutschera, V.E., Hallström, B.M., Klassert, D., Fain, S.R., Leonard, J.A., Arnason, U. & A. Janke (2012) : Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage. - Science. 336: 344-347.

Hailer, F., Kutschera, V.E., Hallström, B.M., Fain, S.R., Leonard, J.A., Arnason, U. & A. Janke (2013) : Response to Comment on ‘Nuclear Genomic Sequences Reveal that Polar Bears Are an Old and Distinct Bear Lineage’. - Science 339: 1522, doi: 10.1126/science.1228066

Hailer, F., James, H.F., Olson, S.L. and Robert C. Fleischer (2015): : Distinct and extinct: Genetic differentiation of the Hawaiian eagle. - Molecular Phylogenetics and Evolution, Vol. 83, February 2015, 40–43

Kalchhauser, I., Kutschera, V.E. & P. Burkhardt-Holm (2014) : The complete mitochondrial genome of the invasive Ponto-Caspian goby Ponticola kessleri obtained from high-throughput sequencing using the Ion Torrent Personal Genome Machine. - Mitochondrial DNA: 1-3.

Kawai, K., Hailer, F., de Guia, A.P., Ichikawa, H. & T. Saitoh (2013) : Refugia in glacial ages lead to the current discontinuous distribution patterns of the dark red-backed vole Myodes rex on Hokkaido, Japan. - Zoological Science, in press.

Kleven, O., Hallström, B.M., Hailer, F., Janke, A., Hagen, S.B., Kopatz, A. & G.H. Eiken (2012) : Identification and evaluation of novel di- and tetranucleotide microsatellite markers from the brown bear (Ursus arctos). - Conservation Genetics Resources 4: 737-741.

Kuhn, T., Hailer, F., Palm, H.W. & S. Klimpel (2013) : Global assessment of molecularly identified Anisakis Dujardin, 1845 (Nematoda: Anisakidae) in their teleost intermediate hosts. - Folia Parasitologica 60(2): 123-134.

Kutschera, V. E., Bidon, T., Hailer, F., Rodi, J. L., Fain, S. R., & A. Janke (2014) : Bears in a forest of gene trees: Phylogenetic inference is complicated by incomplete lineage sorting and gene flow. - Molecular Biology and Evolution 31(8):2004–2017

Kutschera, V.E., Frosch, C., Janke, A., Skirnisson, K., Bidon, T., Lecomte, N., Fain, S.R., Eiken, H.G., Hagen, S.B,. Arnason, U., Laidre, K.L., Nowak, C. & F. Hailer (2016) : High genetic variability of vagrant polar bears illustrates importance of population connectivity in fragmented sea ice habitats. - Animal conservation, doi:10.1111/acv.12250.

Kutschera, V.E., Lecomte, N., Janke, A., Selva, N., Sokolov, A.A., Haun, T., Steyer, K., Nowak, C. & F. Hailer (2013) : A range-wide synthesis and timeline for phylogeographic events in the red fox (Vulpes vulpes). - BMC Evolutionary Biology 13(1): 114.

Langguth, T., Honnen, A.C., Hailer, F., Mizera, M., Skoric, S., Väli, Ü. & F.E. Zachos (2013) : Genetic structure and phylogeography of a European flagship species, the white-tailed sea eagle (Haliaeetus albicilla). - Journal of Avian Biology 44(3): 263-271, doi: 10.1111/j.1600-048X.2012.00075.x.

Psouni, E., Janke, A. & M. Garwicz (2012) : Impact of Carnivory on Human Development and Evolution Revealed by a New Unifying Model of Weaning in Mammals. - PLoS ONE 7(4): e32452.

Sanchez Donoso, I., Huisman, J., Echagaray, J., Puigcerver, M., Rodríguez Teijeiro, J.D., Hailer, F. & C. Vilà (2014) :

Detecting slow introgression of invasive alleles in an extensively restocked game bird. - Frontiers in Ecology and Evolution 2: 15.

Schregel, J., Eiken, H.G., Gröndahl, F.A., Hailer, F., Aspi, J., Kojola, I., Tirronen, K., Danilov, P., Rykov, A., Poroshin, E., Janke, A., Swenson, J.E. & S.B. Hagen (2015) : Y chromosome haplotype distribution of brown bears (Ursus arctos) in Northern Europe provides insight into population history and recovery. - Molecular Ecology

Tobias Bidon, Alexander Kopatz, Dr. Frank Hailer (2013) : Geschlechtsbestimmung bei Wildtieren, Labor&more
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