Per Erik Jorde's homepage

Senior researcher, CEES, University of Oslo

Contact information

Tel: (+47) 37 15 90 11
E-mail: p.e.jorde@bio.uio.no
Office: Institute of Marine Research, Flødevigen, N-4817 His, Norway

Research interest

My research interests focus broadly on application of molecular genetic techniques to characterize biological populations. I have done population genetic research on organisms as diverse as plants and mammals, but most research attention has been devoted to freshwater and marine fishes. Main research topics are spatial genetic differentiation patterns and population identification, and temporal genetic change and estimation of effective population size.

Recent research questions include: To what extent are species structured into distinct breeding units or populations? How large, geographically are these populations? Are they isolated from each other? How temporary stable are local populations? Do they maintain themselves over evolutionary time scales or are local extinction and recolonization frequent? What are the genetically effective sizes of local populations? Do local populations depend on interaction (gene flow) with conspecifics for maintaining genetic variability and avoiding inbreeding? These and similar questions are addressed partly by empirical investigations of spatio-temporal genetic differentiation patterns, and partly by theoretical modeling and computer simulations.

Download my CV.

Software

The following computer software is available under the GNU General Public Licence (GPL). Zip files include source code and compiled programs for Linux and MS Windows, an example data file, and a README.txt file with details.

TempoFs (Jorde, P.E., and N. Ryman, 2007. Unbiased estimator for genetic drift and effective population size. Genetics 177: 927-935 [PDF])

FactorC2 (Jorde, P.E., 2012. Allele frequency covariance among cohorts and its use in estimating effective size of age-structured populations. Molecular Ecology Resources 12: 476-480 [remote PDF])

Old version: FactorC (Jorde, P.E., and N. Ryman, 1995. Temporal allele frequency change and estimation of effective size in populations with overlapping generations. Genetics 139: 1077-1090 [PDF])

Bibliography

Note that recent papers are accessed from the publisher's web site ('remote PDF') and may require journal subscription for download (or e-mail me for a copy).

Hössjer, O., P.E. JORDE, and N. Ryman, 2013. Quasi equilibrium approximations of the fixation index under neutrality: The finite and infinite island models. Theoretical Population Biology 84: 9-24 [remote PDF]

Serbezov, D. P.E. JORDE, L. Bernatchez, E.M. Olsen, and L.A. Vøllestad, 2012. Life history and demographic determinants of effective/census size ratios as exemplified by brown trout (Salmo trutta). Evolutionary Applications 5: 607-618 [Open Access PDF]

Knutsen, H., P.E. JORDE, O.A. Bergstad, M. Skogen, 2012. Population genetic structure in a deepwater fish Coryphaenoides rupestris: patterns and processes. Marine Ecology Progress Series 460: 233-246 [remote PDF]

Serbezov, D., P.E. JORDE, L. Bernatchez, E.M. Olsen, and L.A. Vøllestad, 2012. Short-term genetic changes: evaluating effective population size estimates in a comprehensively described brown trout (Salmo trutta) population. Genetics 191: 579-592 [remote PDF]

JORDE, P.E., 2012. Allele frequency covariance among cohorts and its use in estimating effective size of age-structured populations. Molecular Ecology Resources 12: 476-480 [remote PDF]

Robalo, J.I., R. Castilho, S.M. Francisco, F. Almada, H. Knutsen, P.E. JORDE, A.M. Pereira, and V.C. Almada, 2012. Northern refugia and recent expansion in the North Sea: the case of the wrasse Symphodus melops (Linnaeus, 1758). Ecology and Evolution 2: 153-164 [remote PDF]

Knutsen, H., E.M. Olsen, P.E. JORDE, S.H. Espeland, C. André, and N.C. Stenseth, 2011. Are low but statistically significant levels of genetic differentiation in marine fishes `biologically meaningful'? A case study of coastal Atlantic cod. Molecular Ecology 20: 768-783 [remote PDF]

Schneider, M., H. Sannæs, P.E. JORDE, and H. Knutsen, 2009. Isolation and characterisation of 11 microsatellite loci in the abyssal carapine grenadier Coryphaenoides carapinus (Actinoperygii, Macrouridae) and cross-amplification in two other deep-sea macrourid species. Conservation Genetics 10: 1869-1871 [PDF]

Knutsen, H., P.E. JORDE, H. Sannæs, A.R. Hoelzel, O.A. Bergstad, S. Stefanni, T. Johansen, and N.C. Stenseth, 2009. Bathymetric barriers promoting genetic structure in the deepwater demersal fish tusk (Brosme brosme). Molecular Ecology 18: 3151-3162 [PDF]

Heggenes, J., K.H. Røed, P.E. JORDE, and Å. Brabrand, 2009. Dynamic micro-geographic and temporal genetic diversity in vertebrates: the case of lake-spawning populations of brown trout (Salmo trutta). Molecular Ecology 18: 1100-1111 [PDF]

Olsen, E.M., H. Knutsen, J. Gjøsæter, P.E. JORDE, J.A. Knutsen, and N.C. Stenseth, 2008. Small-scale biocomplexity in coastal Atlantic cod supporting a Darwinian perspective on fisheries management. Evolutionary Applications 1: 524-533 [PDF]

JORDE, P.E., and N. Ryman, 2007. Unbiased estimator for genetic drift and effective population size. Genetics 177: 927-935 [PDF] [Software].

Knutsen, H., P.E. JORDE, O.T. Albert, A.R. Hoelzel, and N.C. Stenseth, 2007. Population genetic structure in the North Atlantic Greenland halibut: influenced by oceanic current systems? Canadian Journal of Fisheries and Aquatic Sciences 64: 857-866 [PDF]

JORDE, P.E., H. Knutsen, S.H. Espeland, and N.C. Stenseth, 2007. Spatial scale of genetic structuring in coastal cod Gadus morhua and geographic extent of local populations. Marine Ecology Progress Series 343: 229-237 [PDF]

JORDE, P.E., T. Schweder, J.W. Bickham, G.H. Givens, R. Suydam, D. Hunter, and N.C. Stenseth, 2007. Detecting genetic structure in migrating bowhead whales off the coast of Barrow, Alaska. Molecular Ecology 16: 1993-2004 [PDF]

Ryman N., S. Palm, C. André, G.R. Carvalho, T.G. Dahlgren, P.E. JORDE, L. Laikre, L.C. Larsson, A. Palmé, and D.E. Ruzzante, 2006. Power for detecting genetic divergence: differences between statistical methods and marker loci. Molecular Ecology 15: 2031-2045 [PDF]

Stenseth, N.C., P.E. JORDE, K.-S. Chan, E. Hansen, H. Knutsen, C. André, M.D. Skogen, and K. Lekve, 2006. Ecological and genetic impact of Atlantic cod larval drift in the Skagerrak. Proceedings of the Royal Society of London, B, Biological sciences 273: 1085-1092 [PDF] [Suppl.]

JORDE, P.E., E.K. Rueness, N.C. Stenseth, and K.S. Jakobsen, 2006. Cryptic population structuring in Scandinavian lynx: reply to Pamilo. Molecular Ecology 15: 1189-1192 [PDF]

Ehrich, D., and P.E. JORDE, 2005. High genetic variability despite high-amplitude population cycles in lemmings. Journal of Mammalogy 86: 380-385 [PDF]

Knutsen, H., C. André, P.E. JORDE, M.D. Skogen, E. Thuróczy, and N.C. Stenseth, 2004. Transport of North Sea cod larvae into the Skagerrak coastal populations. Proceedings of the Royal Society of London. B, Biological sciences 271: 1337-1344 [PDF]

Olsen, E.M., H. Knutsen, J. Gjøsæter, P.E. JORDE, J.A. Knutsen, and N.C. Stenseth, 2004. Life-history variation among local populations of Atlantic cod from the Norwegian Skagerrak coast. Journal of Fish Biology 64: 1725-1730 [PDF]

Rueness, E.K., P.E. JORDE, L. Hellborg, N.C. Stenseth, H. Ellegren, and K.S. Jakobsen, 2003. Cryptic population structure in a large, mobile mammalian predator: the Scandinavian lynx. Molecular Ecology 12: 2623-2633 [PDF]

Palm, S., L. Laikre, P.E. JORDE, and N. Ryman, 2003. Effective population size and temporal genetic change in stream resident brown trout (Salmo trutta, L.). Conservation Genetics 4: 249-264 [PDF]

Knutsen, H., P.E. JORDE, C. André, and N.C. Stenseth, 2003. Fine-scaled geographical population structuring in a highly mobile marine species: the Atlantic cod. Molecular Ecology 12: 385-394 [PDF]

Ryman, N., P.E. JORDE, 2001. Statistical power when testing for genetic differentiation. Molecular Ecology 10: 2361-2374 [PDF]

Knutsen, H., J.A. Knutsen, and P.E. JORDE, 2001. Genetic evidence for mixed origin of recolonized sea trout populations. Heredity 87: 207-214 [PDF]

Ehrich, D., P.E. JORDE, C.J. Krebs, A.J. Kenney, J.E. Stacy, and N.C. Stenseth, 2001. Spatial structure of lemming populations (Dicrostonyx groenlandicus) fluctuating in density. Molecular Ecology 10: 481-496 [PDF]

Knutsen, H., B.A. Rukke, P.E. JORDE, and R.A. Ims, 2000. Genetic differentiation among populations of the beetle Bolitophagus reticulatus (Coleoptera: Tenebrionidae) in a fragmented and a continuous landscape. Heredity 84: 667-676 [PDF]

JORDE, P.E., S. Palm, and N. Ryman, 1999. Estimating genetic drift and effective population size from temporal shifts of dominant gene marker frequencies. Molecular Ecology 8: 1171-1178 [PDF]

Ryman, N., P.E. JORDE, and L. Laikre, 1999. Supportive breeding and inbreeding effective number: reply to Nomura. Conservation Biology 13: 673-676 [PDF]

Nilsson, T. and P.E. JORDE, 1998. Allozyme variation in allotetraploid Saxifraga osloensis and its diploid progenitors. Nordic Journal of Botany 18: 425-430 [remote PDF]

Laikre, L., P.E. JORDE, and N. Ryman, 1998. Temporal change of mitochondrial DNA haplotype frequencies and female effective size in a brown trout (Salmo trutta) population. Evolution 52: 910-915 [PDF]

Stacy, J.E., P.E. JORDE, H. Steen, R.A. Ims, A. Purvis, and K.S. Jakobsen, 1997. Lack of concordance between mtDNA gene flow and population density fluctuations in the bank vole. Molecular Ecology 6: 751-759 [PDF]

Thorsén, J., P.E. JORDE, F.A. Aravanopoulos, U. Gullberg, and L. Zsuffa, 1997. Inheritance and linkage of isozyme loci in the basket willow (Salix viminalis L.). Journal of Heredity 88: 144-150 [PDF]

JORDE, P.E., and N. Ryman, 1996. Demographic genetics of brown trout (Salmo trutta) and estimation of effective population size from temporal change of allele frequencies. Genetics 143: 1369-1381 [PDF]

Laikre, L., P.A. Prodöhl, P.E. JORDE, and N. Ryman, 1995. Genetic variability at minisatellite and allozyme loci in brown trout (Salmo trutta) -A comparison. Hereditas 123: 191-195 [PDF]

Ryman, N., P.E. JORDE, and L. Laikre, 1995. Supportive breeding and variance effective population size. Conservation Biology 79: 1619-1628 [PDF]

JORDE, P.E., and N. Ryman, 1995. Temporal allele frequency change and estimation of effective size in populations with overlapping generations. Genetics 139: 1077-1090 [PDF] [Software].

JORDE, P.E., A. Gitt, and N. Ryman, 1991. New biochemical genetic markers in the brown trout (Salmo trutta L.). Journal of Fish Biology 39: 451-454 [PDF]

Garcia-Marin, J.L., P.E. JORDE, N. Ryman, F. Utter, and C. Pla, 1991. Management implications of genetic differentiation between native and hatchery populations of brown trout (Salmo trutta) in Spain. Aquaculture 95: 235-249 [remote PDF]

JORDE, P.E., and N. Ryman, 1990. Allele frequency estimation at loci with incomplete co-dominant expression. Heredity 65: 429-433 [PDF]