Thomas Fredrik Hansen

• Hansen, Thomas Fredrik; Bolstad, Geir Hysing & Tsuboi, Masahito (2021). Analyzing Disparity and Rates of Morphological Evolution with Model-Based Phylogenetic Comparative Methods. Systematic Biology. ISSN 1063-5157. doi: 10.1093/sysbio/syab079. Fulltekst i vitenarkiv Vis sammendrag

  Understanding variation in rates of evolution and morphological disparity is a goal of macroevolutionary research. In aphylogeneticcomparativemethods framework,we present three explicit models for linking the rate of evolution of a trait to the state of another evolving trait. This allows testing hypotheses about causal influences on rates of phenotypic evolution with phylogenetic comparative data. We develop a statistical framework for fitting the models with generalized least-squares regression and use this to discuss issues and limitations in the study of rates of evolution more generally.We showthat the power to detect effects on rates of evolution is lowin that even strong causal effects are unlikely to explain more than a few percent of observed variance in disparity. We illustrate the models and issues by testing if rates of beak-shape evolution in birds are influenced by brain size, as may be predicted from a Baldwin effect in which presumptively more behaviorally flexible large-brained species generatemore novel selection on themselves leading to higher rates of evolution. From an analysis of morphometric data for 645 species, we find evidence that both macro- and microevolution of the beak are faster in birds with larger brains, but with the caveat that there are no consistent effects of relative brain size.[Baldwin effect; beak shape; behavioral drive; bird; brain size; disparity; phylogenetic comparative method; rate of evolution.]

• Hansen, Thomas F. & Pélabon, Christophe (2021). Evolvability: A Quantitative-Genetics Perspective. Annual Review of Ecology, Evolution and Systematics. ISSN 1543-592X. 52, s. 153–175. doi: 10.1146/annurev-ecolsys-011121-021241.
• Pelabon, Christophe; Albertsen, Elena; Le Rouzic, Arnaud; Firmat, Cyril; Bolstad, Geir Hysing & Armbruster, W. Scott [Vis alle 7 forfattere av denne artikkelen] (2021). Quantitative assessment of observed versus predicted responses to selection. Evolution. ISSN 0014-3820. 75(9), s. 2217–2236. doi: 10.1111/evo.14284. Fulltekst i vitenarkiv Vis sammendrag

  Although artificial-selection experiments seem well suited to testing our ability to predict evolution, the correspondence between predicted and observed responses is often ambiguous due to the lack of uncertainty estimates. We present equations for assessing prediction error in direct and indirect responses to selection that integrate uncertainty in genetic parameters used for prediction and sampling effects during selection. Using these, we analyzed a selection experiment on floral traits replicated in two taxa of the Dalechampia scandens (Euphorbiaceae) species complex for which G-matrices were obtained from a diallel breeding design. After four episodes of bidirectional selection, direct and indirect responses remained within wide prediction intervals, but appeared different from the predictions. Combined analyses with structural-equation models confirmed that responses were asymmetrical and lower than predicted in both species. We show that genetic drift is likely to be a dominant source of uncertainty in typically-dimensioned selection experiments in plants and a major obstacle to predicting short-term evolutionary trajectories.

• Albertsen, Elena; Opedal, Øystein Hjorthol; Bolstad, Geir Hysing; Pérez-Barrales, Rocío; Hansen, Thomas F & Pelabon, Christophe [Vis alle 7 forfattere av denne artikkelen] (2020). Using ecological context to interpret spatiotemporal variation in natural selection. Evolution. ISSN 0014-3820. s. 1–16. doi: 10.1111/evo.14136. Fulltekst i vitenarkiv
• Tsuboi, Masahito; Kopperud, Bjørn Tore; Syrowatka, Christine; Grabowski, Mark Walter; Voje, Kjetil L. & Pelabon, Christophe [Vis alle 7 forfattere av denne artikkelen] (2020). Measuring Complex Morphological Traits with 3D Photogrammetry: A Case Study with Deer Antlers. Evolutionary Biology. ISSN 0071-3260. 47, s. 175–186. doi: 10.1007/s11692-020-09496-9. Fulltekst i vitenarkiv
• Hansen, Thomas F; Solvin, Thomas Mørtvedt & Pavlicev, Mihaela (2019). Predicting evolutionary potential: A numerical test of evolvability measures. Evolution. ISSN 0014-3820. 73(4), s. 689–703. doi: 10.1111/evo.13705. Vis sammendrag

  Despite sophisticated mathematical models, the theory of microevolution is mostly treated as a qualitative rather than a quantitative tool. Numerical measures of selection, constraints, and evolutionary potential are often too loosely connected to theory to provide operational predictions of the response to selection. In this paper, we study the ability of a set of operational measures of evolvability and constraint to predict short‐term selection responses generated by individual‐based simulations. We focus on the effects of selective constraints under which the response in one trait is impeded by stabilizing selection on other traits. The conditional evolvability is a measure of evolutionary potential explicitly developed for this situation. We show that the conditional evolvability successfully predicts rates of evolution in an equilibrium situation, and further that these equilibria are reached with characteristic times that are inversely proportional to the fitness load generated by the constraining characters. Overall, we find that evolvabilities and conditional evolvabilities bracket responses to selection, and that they together can be used to quantify evolutionary potential on time scales where the G‐matrix remains relatively constant.

• Toljagic, Olja; Voje, Kjetil L.; Matschiner, Michael; Liow, Lee Hsiang & Hansen, Thomas F (2018). Millions of Years Behind: Slow Adaptation of Ruminants to Grasslands. Systematic Biology. ISSN 1063-5157. 67(1), s. 145–157. doi: 10.1093/sysbio/syx059.
• Houle, David; Bolstad, Geir Hysing; van der Linde, Kim & Hansen, Thomas F (2017). Mutation predicts 40 million years of fly wing evolution. Nature. ISSN 0028-0836. 548(7668), s. 447–450. doi: 10.1038/nature23473. Fulltekst i vitenarkiv Vis sammendrag

  Mutation enables evolution, but the idea that adaptation is also shaped by mutational variation is controversial1–4. Simple evolutionary hypotheses predict such a relationship if the supply of mutations constrains evolution5,6, but it is not clear that constraints exist, and, even if they do, they may be overcome by long-term natural selection. Quantification of the relationship between mutation and phenotypic divergence among species will help to resolve these issues. Here we use precise data on over 50,000 Drosophilid fly wings to demonstrate unexpectedly strong positive relationships between variation produced by mutation, standing genetic variation, and the rate of evolution over the last 40 million years. Our results are inconsistent with simple constraint hypotheses because the rate of evolution is very low relative to what both mutational and standing variation could allow. In principle, the constraint hypothesis could be rescued if the vast majority of mutations are so deleterious that they cannot contribute to evolution, but this also requires the implausible assumption that deleterious mutations have the same pattern of effects as potentially advantageous ones. Our evidence for a strong relationship between mutation and divergence in a slowly evolving structure challenges the existing models of mutation in evolution.

• Armbruster, W. Scott; Bolstad, Geir Hysing; Hansen, Thomas F; Keller, Barbara; Conti, Elena & Pelabon, Christophe (2017). The measure and mismeasure of reciprocity in heterostylous flowers. New Phytologist. ISSN 0028-646X. 215, s. 906–917. doi: 10.1111/nph.14604. Fulltekst i vitenarkiv Vis sammendrag

  The goal of biological measurement is to capture underlying biological phenomena in numerical form. The reciprocity index applied to heterostylous flowers is meant to measure the degree of correspondence between fertile parts of opposite sex on complementary (inter-compatible) morphs, reflecting the correspondence of locations of pollen placement on, and stigma contact with, pollinators. Pollen of typical heterostylous flowers can achieve unimpeded fertilization only on opposite-morph flowers. Thus, the implicit goal of this measurement is to assess the likelihood of ‘legitimate’ pollinations between compatible morphs, and hence reproductive fitness. Previous reciprocity metrics fall short of this goal on both empirical and theoretical grounds. We propose a new measure of reciprocity based on theory that relates floral morphology to reproductive fitness. This method establishes a scale based on adaptive inaccuracy, a measure of the fitness cost of the deviation of phenotypes in a population from the optimal phenotype. Inaccuracy allows the estimation of independent contributions of maladaptive bias (mean departure from optimum) and imprecision (within-population variance) to the phenotypic mismatch (inaccuracy) of heterostylous morphs on a common scale. We illustrate this measure using data from three species of Primula (Primulaceae). adaptive accuracy, floral dimorphisms, heterostyly, maladaptation, measurement theory, phenotypic load, pollination, Primula.

• Opedal, Øystein Hjorthol; Bolstad, Geir Hysing; Hansen, Thomas F; Armbruster, William Scott & Pelabon, Christophe (2017). The evolvability of herkogamy: Quantifying the evolutionary potential of a composite trait. Evolution. ISSN 0014-3820. 71(6), s. 1572–1586. doi: 10.1111/evo.13258.
• Mayer, Christine & Hansen, Thomas F (2017). Evolvability and Robustness: A paradox restored. Journal of Theoretical Biology. ISSN 0022-5193. 430, s. 78–85. doi: 10.1016/j.jtbi.2017.07.004.
• Hansen, Thomas F (2017). On the definition and measurement of fitness in finite populations. Journal of Theoretical Biology. ISSN 0022-5193. 419, s. 36–43. doi: 10.1016/j.jtbi.2016.12.024.
• Falahati-Anbaran, Mohsen; Stenøien, Hans K.; Bolstad, Geir Hysing; Hansen, Thomas F; Pérez‐Barrales, Rocio & Armbruster, William Scott [Vis alle 7 forfattere av denne artikkelen] (2017). Novel microsatellite markers for Dalechampia scandens (Euphorbiaceae) and closely related taxa: application to studying a species complex. Plant Species Biology. ISSN 0913-557X. 32(2), s. 179–186. doi: 10.1111/1442-1984.12142. Fulltekst i vitenarkiv
• Hansen, Thomas F (2016). On bias and precision in metaanalysis: the error in the error. Journal of Evolutionary Biology. ISSN 1010-061X. 29, s. 1919–1921. doi: 10.1111/jeb.12947.
• Malmstrøm, Martin; Matschiner, Michael; Tørresen, Ole Kristian; Star, Bastiaan; Snipen, Lars-Gustav & Hansen, Thomas F [Vis alle 13 forfattere av denne artikkelen] (2016). Evolution of the immune system influences speciation rates in teleost fishes. Nature Genetics. ISSN 1061-4036. 48(10), s. 1204–1210. doi: 10.1038/ng.3645. Fulltekst i vitenarkiv
• Grabowski, Mark Walter; Voje, Kjetil L. & Hansen, Thomas F (2016). Evolutionary modeling and correcting for observation error support a 3/5 brain-body allometry for primates. Journal of Human Evolution. ISSN 0047-2484. 94, s. 106–116. doi: 10.1016/j.jhevol.2016.03.001.
• Hansen, Thomas F (2015). Evolutionary Constraints. I Losos, Jonathan (Red.), Oxford Bibliographies in Evolutionary Biology. Oxford University Press. ISSN 9780199941728. s. 1–28. doi: 10.1093/OBO/9780199941728-0061.
• Hansen, Thomas F (2015). Measuring gene interactions. Methods in molecular biology. ISSN 1064-3745. 1253, s. 115–143. doi: 10.1007/978-1-4939-2155-3_7.
• Tarka, Maja; Bolstad, Geir Hysing; Wacker, Sebastian; Räsänen, Katja; Hansen, Thomas F & Pelabon, Christophe (2015). Did natural selection make the Dutch taller? A cautionary note on the importance of quantification in understanding evolution. Evolution. ISSN 0014-3820. 69(12), s. 3204–3206. doi: 10.1111/evo.12803.
• Bolstad, Geir Hysing; Cassara, Jason A.; Marquez, Eladio; Hansen, Thomas F; van der Linde, Kim & Houle, David [Vis alle 7 forfattere av denne artikkelen] (2015). Complex constraints on allometry revealed by artificial selection on the wing of Drosophila melanogaster. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 112(43), s. 13284–13289. doi: 10.1073/pnas.1505357112. Fulltekst i vitenarkiv Vis sammendrag

  Precise exponential scaling with size is a fundamental aspect of phenotypic variation. These allometric power laws are often invariant across taxa and have long been hypothesized to reflect developmental constraints. Here we test this hypothesis by investigating the evolutionary potential of an allometric scaling relationship in drosophilid wing shape that is nearly invariant across 111 species separated by at least 50 million years of evolution. In only 26 generations of artificial selection in a population of Drosophila melanogaster, we were able to drive the allometric slope to the outer range of those found among the 111 sampled species. This response was rapidly lost when selection was suspended. Only a small proportion of this reversal could be explained by breakup of linkage disequilibrium, and direct selection on wing shape is also unlikely to explain the reversal, because the more divergent wing shapes produced by selection on the allometric intercept did not revert. We hypothesize that the reversal was instead caused by internal selection arising from pleiotropic links to unknown traits. Our results also suggest that the observed selection response in the allometric slope was due to a component expressed late in larval development and that variation in earlier development did not respond to selection. Together, these results are consistent with a role for pleiotropic constraints in explaining the remarkable evolutionary stability of allometric scaling. allometry | artificial selection | comparative analyses | developmental constraints | pleiotropy

• Le Rouzic, Arnaud; Hansen, Thomas F; Gosden, Thomas P. & Svensson, Erik I. (2015). Evolutionary time-series analysis reveals the signature of frequency-dependent selection on a female mating polymorphism. The American Naturalist. ISSN 0003-0147. 185(6), s. E182–E196. doi: 10.1086/680982. Fulltekst i vitenarkiv
• Hansen, Thomas F (2014). Use and Misuse of Comparative Methods in the Study of Adaptation. I László Zsolt, Garamszegi (Red.), Modern Phylogenetic Comparative Methods and Their Application in Evolutionary Biology. Springer. ISSN 978-3-662-43550-2. s. 351–379. doi: 10.1007/978-3-662-43550-2_14.
• Pelabon, Christophe; Firmat, Cyril Joel Patrick; Bolstad, Geir Hysing; Voje, Kjetil L.; Houle, David & Cassara, Jason [Vis alle 8 forfattere av denne artikkelen] (2014). Evolution of morphological allometry. Annals of the New York Academy of Sciences. ISSN 0077-8923. 1320(1), s. 58–75. doi: 10.1111/nyas.12470. Fulltekst i vitenarkiv
• Bolstad, Geir Hysing; Hansen, Thomas F; Pelabon, Christophe; Falahati-Anbaran, Mohsen; Perez-Barrales, Rocio & Armbruster, William Scott (2014). Genetic constraints predict evolutionary divergence in Dalechampia blossoms. Philosophical Transactions of the Royal Society of London. Biological Sciences. ISSN 0962-8436. 369(1649). doi: 10.1098/rstb.2013.0255.
• Armbruster, William Scott; Pelabon, Christophe; Bolstad, Geir Hysing & Hansen, Thomas F (2014). Integrated phenotypes: Understanding trait covariation in plants and animals. Philosophical Transactions of the Royal Society of London. Biological Sciences. ISSN 0962-8436. 369(1649). doi: 10.1098/rstb.2013.0245.
• Firmat, Cyril Joel Patrick; Lozano-Fernandez, I; Agusti, J; Bolstad, Geir Hysing; Cuenca-Bescos, G & Hansen, Thomas F [Vis alle 7 forfattere av denne artikkelen] (2014). Walk the line: 600 000 years of molar evolution constrained by allometry in the fossil rodent Mimomys savini. Philosophical Transactions of the Royal Society of London. Biological Sciences. ISSN 0962-8436. 369(1649). doi: 10.1098/rstb.2014.0057.
• Voje, Kjetil L.; Hansen, Thomas F; Egset, Camilla Kalvatn; Bolstad, Geir Hysing & Pelabon, Christophe (2014). Allometric constraints and the evolution of allometry. Evolution. ISSN 0014-3820. 68(3), s. 866–885. doi: 10.1111/evo.12312.
• Falahati-Anbaran, Mohsen; Stenøien, Hans K.; Pelabon, Christophe; Bolstad, Geir Hysing; Perez-Barrales, Rocio & Hansen, Thomas F [Vis alle 7 forfattere av denne artikkelen] (2013). Development of microsatellite markers for the neotropical vine Dalechampia scandens (Euphorbiaceae). American Journal of Botany. ISSN 0002-9122. 1(6). doi: 10.3732/apps.1200492.
• Voje, Kjetil Lysne & Hansen, Thomas F (2013). Evolution of static allometries: adaptive change in allometric slopes of eye span in stalk-eyed flies. Evolution. ISSN 0014-3820. 67(2), s. 453–467. doi: 10.1111/j.1558-5646.2012.01777.x.
• Hansen, Thomas F (2013). Why epistasis is important for selection and adaptation. Evolution. ISSN 0014-3820. 67(12), s. 3501–3511. doi: 10.1111/evo.12214.
• Le Rouzic, Arnaud; Alvarez-Castro, Jose M. & Hansen, Thomas F (2013). The Evolution of Canalization and Evolvability in Stable and Fluctuating Environments. Evolutionary Biology. ISSN 0071-3260. 40(3), s. 317–340. doi: 10.1007/s11692-012-9218-z.
• Perez-Barrales, Rocio; Bolstad, Geir Hysing; Pelabon, Christophe; Hansen, Thomas F & Armbruster, William Scott (2013). Pollinators and seed predators generate conflicting selection on Dalechampia blossoms. Oikos. ISSN 0030-1299. 122(10), s. 1411–1428. doi: 10.1111/j.1600-0706.2013.20780.x.
• Voje, Kjetil Lysne; Mazzarella, Anna Virginia Black; Hansen, Thomas F; Østbye, Kjartan; Klepaker, Tom Olav & Bass, Arthur [Vis alle 10 forfattere av denne artikkelen] (2013). Adaptation and constraint in a stickleback radiation. Journal of Evolutionary Biology. ISSN 1010-061X. 26(11), s. 2396–2414. doi: 10.1111/jeb.12240.
• Armbruster, W. Scott; Hansen, Thomas F; Bolstad, Geir Hysing; Perez-Barrales, Rocio & Pelabon, Christophe (2012). Adaptive accuracy and adaptive landscapes. I Svensson, Erik I. & Calsbeek, Ryan (Red.), The adaptive landscape in evolutionary biology. Oxford University Press. ISSN 978-0-19-959537-2. s. 150–168. doi: 10.1093/acprof%3Aoso/9780199595372.003.0010.
• Hansen, Thomas F (2012). Adaptive Landscapes and Macroevolutionary Dynamics. I Svensson, Erik I. & Calsbeek, Ryan (Red.), The adaptive landscape in evolutionary biology. Oxford University Press. ISSN 978-0-19-959537-2. s. 205–226. doi: 10.1093/acprof%3Aoso/9780199595372.003.0013.
• Bartoszek, Krzystof; Pienaar, Jason; Mostad, Petter; Andersson, Staffan & Hansen, Thomas F (2012). A phylogenetic comparative method for studying multivariate adaptation. Journal of Theoretical Biology. ISSN 0022-5193. 314, s. 204–215. doi: 10.1016/j.jtbi.2012.08.005.
• Hansen, Thomas F & Bartoszek, Krzysztof (2012). Interpreting the Evolutionary Regression: The Interplay Between Observational and Biological Errors in Phylogenetic Comparative Studies. Systematic Biology. ISSN 1063-5157. 61(3), s. 413–425. doi: 10.1093/sysbio/syr122.
• Escudero, Marcial; Hipp, Andrew L.; Hansen, Thomas F; Voje, Kjetil Lysne & Luceño, Modesto (2012). Selection and inertia in the evolution of holocentric chromosomes in sedges (Carex, Cyperaceae). New Phytologist. ISSN 0028-646X. 195(1), s. 237–247. doi: 10.1111/j.1469-8137.2012.04137.x.
• Pelabon, Christophe; Thöne, Patrick; Hansen, Thomas F & Armbruster, William Scott (2012). Signal honesty and cost of pollinator rewards in Dalechampia scandens (Euphorbiaceae). Annals of Botany. ISSN 0305-7364. 109(7), s. 1331–1339. doi: 10.1093/aob/mcs091.
• Egset, Camilla Kalvatn; Hansen, Thomas F; Le Rouzic, Arnaud; Bolstad, Geir Hysing; Rosenqvist, Gunilla & Pelabon, Christophe (2012). Artificial selection on allometry: change in elevation but not slope. Journal of Evolutionary Biology. ISSN 1010-061X. 25(5), s. 938–948. doi: 10.1111/j.1420-9101.2012.02487.x. Fulltekst i vitenarkiv
• Hansen, Thomas F & Voje, Kjetil Lysne (2011). DEVIATION FROM THE LINE OF LEAST RESISTANCE DOES NOT EXCLUDE GENETIC CONSTRAINTS: A COMMENT ON BERNER ET AL. (2010). Evolution. ISSN 0014-3820. 65(6), s. 1821–1822. doi: 10.1111/j.1558-5646.2011.01281.x.
• Hansen, Thomas F (2011). Epigenetics: Adaptation or Contingency? Epigenetics: Linking genotype and phenotype in development and evolution. University of California Press. ISSN 9780520267091. s. 357–376.
• Pavlicev, Mihaela & Hansen, Thomas F (2011). Genotype-Phenotype Maps Maximizing Evolvability: Modularity Revisited. Evolutionary Biology. ISSN 0071-3260. 38(4), s. 371–389. doi: 10.1007/s11692-011-9136-5.
• Uyeda, Josef; Hansen, Thomas F; Arnold, Stevan J & Pienaar, Jason (2011). The million-year wait for macroevolutionary bursts. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 108(38), s. 15908–15913. doi: 10.1073/pnas.1014503108.
• Le Rouzic, Arnaud; Østbye, Kjartan; Klepaker, Tom Olav; Hansen, Thomas F; Bernatchez, Louis & Schluter, Dolph [Vis alle 7 forfattere av denne artikkelen] (2011). Strong and consistent natural selection associated with armour reduction in sticklebacks. Molecular Ecology. ISSN 0962-1083. 20, s. 2483–2493. doi: 10.1111/j.1365-294X.2011.05071.x.
• Le Rouzic, Arnaud; Houle, David & Hansen, Thomas F (2011). A modelling framework for the analysis of artificial-selection time series. Genetics Research. ISSN 0016-6723. 93(2), s. 155–173. doi: 10.1017/s0016672311000024.
• Houle, David; Pelabon, Christophe; Wagner, Günter P. & Hansen, Thomas F (2011). Measurement and meaning in biology. The Quarterly review of biology. ISSN 0033-5770. 86(1), s. 3–34. doi: 10.1086/658408.
• Pelabon, Christophe; Armbruster, William Scott & Hansen, Thomas F (2011). Experimental evidence for the Berg hypothesis: vegetative traits are more sensitive than pollination traits to environmental variation. Functional Ecology. ISSN 0269-8463. 25(1), s. 247–257. doi: 10.1111/j.1365-2435.2010.01770.x.
• Labra, Antonieta; Voje, Kjetil Lysne; Seligmann, Hervé & Hansen, Thomas F (2010). Evolution of the third eye: a phylogenetic comparative study of parietal-eye size as an ecophysiological adaptation in Liolaemus lizards. Biological Journal of the Linnean Society. ISSN 0024-4066. 101(4), s. 870–883. doi: 10.1111/j.1095-8312.2010.01541.x.
• Fierst, Janna & Hansen, Thomas F (2010). Genetic architecture and postzygotic reproductive isolation: Evolution of Bateson-Dobzhansky-Muller incompatibilities in a polygenic Model. Evolution. ISSN 0014-3820. 64(3), s. 675–693. doi: 10.1111/j.1558-5646.2009.00861.x.
• Bolstad, Geir H; Armbruster, W. Scott; Pelabon, Christophe; Pérez-Barrales, R & Hansen, Thomas F (2010). Direct selection at the blossom level on floral reward by pollinators in a natural population of Dalechampia schottii: full-disclosure honesty? New Phytologist. ISSN 0028-646X. 188(2), s. 370–384. doi: 10.1111/j.1469-8137.2010.03429.x. Vis sammendrag

  • Both floral rewards and advertisements can be important in the attraction of pollinators, but few studies have separated the individual contributions of rewards and advertisements to fitness. • Here, we investigated selection by pollinators on individual blossoms in Dalechampia schottii. This Neotropical vine, endemic to the Yucata´n Peninsula, rewards bees by secreting fully visible, deep-blue resin from a gland subtended by two conspicuous petaloid bracts that may play the role of advertisement. • We used contextual analysis to build a fitness function for four morphological traits of individual blossoms: the amount of the reward as measured by gland area; the size of the advertisement trait as measured by bract length; the flower-pollinator fit as measured by the shortest distance between reward and stigma; and the potential for self-pollination as measured by the shortest distance between anthers and stigma. • Larger gland area and increased potential for self-pollination directly increased the seed production of individual blossoms. However, bract size or flower-pollinator fit did not influence the number of seeds produced by blossoms. Therefore, in this Dalechampia species, pollinators seem to select directly on the reward of individual blossoms but not on the advertising bracts.

• Le Rouzic, Arnaud; Skaug, Hans Julius & Hansen, Thomas F. (2010). Estimating genetic architectures from artificial-selection responses: A random-effect framework. Theoretical Population Biology. ISSN 0040-5809. 77(2), s. 119–130. doi: 10.1016/j.tpb.2009.12.003.
• Pelabon, Christophe; Hansen, TF; Carter, Ashley J.R. & Houle, David (2010). EVOLUTION OF VARIATION AND VARIABILITY UNDER FLUCTUATING, STABILIZING, AND DISRUPTIVE SELECTION. Evolution. ISSN 0014-3820. 64(7), s. 1912–1925. doi: 10.1111/j.1558-5646.2010.00979.x.
• Pavlicev, Mihaela; Le Rouzic, Arnaud; Cheverud, James; Günter P., Wagner & Hansen, Thomas F (2010). Directionality of Epistasis in a Murine Intercross Population. Genetics. ISSN 0016-6731. 185(4), s. 1489–1505. doi: 10.1534/genetics.110.118356.
• Hansen, Thomas F & Houle, David (2009). Corrigendum. Journal of Evolutionary Biology. ISSN 1010-061X. 22(4), s. 913–915. doi: 10.1111/j.1420-9101.2009.01715.x.
• Armbruster, William Scott; Pelabon, Christophe; Hansen, Thomas & Bolstad, Geir Hysing (2009). Macroevolutionary patterns of pollination accuracy: a comparison of three genera. New Phytologist. ISSN 0028-646X. 183(3), s. 600–617. doi: 10.1111/j.1469-8137.2009.02930.x.
• Armbruster, William Scott; Hansen, TF; Pelabon, Christophe; Pérez-Barrales, R; Perez-Barrales, R & Maad, Johanne (2009). The adaptive accuracy of flowers: measurement and microevolutionary patterns. Annals of Botany. ISSN 0305-7364. 103(9), s. 1529–1545. doi: 10.1093/aob/mcp095.
• Labra, Antonieta; Pienaar, Jason & Hansen, Thomas F (2009). Evolution of Thermal Physiology in Liolaemus Lizards: Adaptation, Phylogenetic Inertia, and Niche Tracking. The American Naturalist. ISSN 0003-0147. 174(2), s. 204–220. doi: 10.1086/600088.
• Hansen, Thomas F; Pienaar, J & Orzack, SH (2008). A comparative method for studying adaptation to a randomly evolving environment. Evolution. ISSN 0014-3820. 62, s. 1965–1977. doi: 10.1111/j.1558-5646.2008.00412.x.
• Hansen, Thomas F & Houle, D (2008). Measuring and comparing evolvability and constraint in multivariate characters. Journal of Evolutionary Biology. ISSN 1010-061X. 21, s. 1201–1219. doi: 10.1111/j.1420-9101.2008.01573.x.
• Pelabon, Christophe; Pélabon, Christophe & Hansen, Thomas (2008). On the adaptive accuracy of directional asymmetry in insect wing size. Evolution. ISSN 0014-3820. 62(11), s. 2855–2867. doi: 10.1111/j.1558-5646.2008.00495.x.
• Hansen, TF; Pelabon, Christophe & Armbruster, William Scott (2007). Comparing variational properties of homologous floral and vegetative characters in Dalechampia scandens: Testing the Berg hypothesis. Evolutionary Biology. ISSN 0071-3260. 34(1-2), s. 86–98. doi: 10.1007/s11692-007-9006-3.
• Tomaiuolo, Maurizio; Hansen, Thomas F & Levitan, Don R. (2007). A theoretical investigation of sympatric evolution of temporal reproductive isolation as illustrated by marine broadcast spawners. Evolution. ISSN 0014-3820. 61, s. 2584–2595. doi: 10.1111/j.1558-5646.2007.00218.x.
• Hansen, Thomas F; Pélabon, Christophe & Armbruster, W. Scott (2007). Comparing variational properties of homologous floral and vegetative characters in Dalechampia scandens: Testing the Berg hypothesis. Evolutionary Biology. ISSN 0071-3260. 34, s. 86–98.
• Hansen, Thomas & Skjeldestad, Finn Egil (2007). Adolescents: Is there an association between knowledge of oral contraceptives and profession of provider? European journal of contraception & reproductive health care. ISSN 1362-5187. 12(4), s. 303–308. doi: 10.1080/13625180701475558.
• Hansen, Thomas F (2006). The evolution of genetic architecture. Annual Review of Ecology and Systematics. ISSN 0066-4162. 37, s. 123–157.
• Hansen, Thomas F (2006). The origins of robustness. Evolution. ISSN 0014-3820. 60, s. 418–420.
• Pélabon, Christophe; Pelabon, Christophe; Hansen, Thomas F; Hansen, Thomas; Carter, Ashley & Houle, David (2006). Response of fluctuating and directional asymmetry to selection on wing shape in Drosophila melanogaster. Journal of Evolutionary Biology. ISSN 1010-061X. 19, s. 764–776. doi: 10.1111/j.1420-9101.2005.01054.x.
• Pélabon, Christophe; Pelabon, Christophe; Hansen, Thomas; Carlson, Matthew & Armbruster, William Scott (2006). Patterns of asymmetry in the twining vine Dalechampia scandens (Euphorbiaceae): ontogenetic and hierarchical perspectives. New Phytologist. ISSN 0028-646X. 170, s. 65–74.
• Hansen, Thomas; Carter, Ashley; Pélabon, Christophe & Pelabon, Christophe (2006). On adaptive accuracy and precision in natural populations. The American Naturalist. ISSN 0003-0147. 168(2), s. 168–181.
• Hansen, Thomas F; Alvarez-Castro, Jose M.; Carter, Ashley J. R.; Hermisson, Joachim & Wagner, Günter P. (2006). Evolution of genetic architecture under directional selection. Evolution. ISSN 0014-3820. 60, s. 1523–1536.
• Pelabon, Christophe; Carlson, ML; Hansen, TF & Armbruster, William Scott (2005). Effects of crossing distance on offspring fitness and developmental stability in Dalechampia scandens (Euphorbiaceae). American Journal of Botany. ISSN 0002-9122. 92(5), s. 842–851.
• Carter, AJR; Hermisson, J & Hansen, Thomas F (2005). The role of epistatic gene interactions in the response to selection and the evolution of evolvability. Theoretical Population Biology. ISSN 0040-5809. 68(3), s. 179–196.
• Pelabon, C; Carlson, ML; Hansen, Thomas F & Armbruster, WS (2005). Effects of crossing distance on offspring fitness and developmental stability in Dalechampia scandens (Euphorbiaceae). American Journal of Botany. ISSN 0002-9122. 92(5), s. 842–851.
• Hansen, Thomas F & Orzack, SH (2005). Assessing current adaptation and phylogenetic inertia as explanations of trait evolution: The need for controlled comparisons. Evolution. ISSN 0014-3820. 59(10), s. 2063–2072.
• Armbruster, William Scott; Pelabon, Christophe; Hansen, TF & Mulder, CPH (2004). Floral integration, modularity and accuracy: distinguishing complex adaptations from genetic constraints. I Pigliucci, Massimo & Preston, KA (Red.), Phenotypic Integration: Studying the Ecology and Evolution of Complex Phenotypes. Oxford University Press. ISSN 0-19-516043-6. s. 23–49.

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• Albertsen, Elena; H. Opedal, Øystein; Bolstad, Geir Hysing; Perez-Barrales, Rocio; Hansen, Thomas F & Pelabon, Christophe [Vis alle 7 forfattere av denne artikkelen] (2020). Using ecological context to interpret spatiotemperal variation in natural selection.
• Bolstad, Geir Hysing; Albertsen, Elena; Perez-Barrales, Rocio; Opedal, Øystein Hjorthol; Armbruster, Scott & Pelabon, Christophe [Vis alle 7 forfattere av denne artikkelen] (2019). Benefits of using non-linear path analysis for estimating natural selection.
• Mayer, Christine & Hansen, Thomas F (2017). Evovability and Robustness in Models of Pattern Formation.
• Hansen, Thomas F (2017). A review of "Genes and Evolution. Current topics in developmental Biology, Volume 119, Edited by Virginie Orgogozo". The Quarterly review of biology. ISSN 0033-5770. 92, s. 479–480.
• Svendsen, Ida Krogsgaard & Hansen, Thomas F (2016). Effects of climate change on biogeography.
• Kopperud, Bjørn Tore & Hansen, Thomas F (2016). Artiodactyl brain size evolution.
• Mayer, Christine & Hansen, Thomas F (2016). Resolving the relationship between evolvability and robustness using Boolean Genotype-Phenotype Maps.
• Hansen, Thomas F (2016). Evolvability, Quantitative Genetics of. I Kliman, Richard M. (Red.), Encyclopedia of Evolutionary Biology. Elsevier. ISSN 9780128000496. s. 83–89. doi: 10.1016/B978-0-12-800049-6.00042-1.
• Hansen, Thomas F (2016). Epistasis. I de la Rosa, Laura Nuno & Müller, Gerd (Red.), Evolutionary Developmental Biology. A Reference Guide. Springer Publishing Company. ISSN 978-3-319-33038-9. s. 1–14. doi: 10.1007/978-3-319-33038-9_53-1.
• Albertsen, Elena; Pelabon, Christophe; Le Rouzic, Arnaud; Firmat, Cyril; Hansen, Thomas F & Bolstad, Geir Hysing [Vis alle 7 forfattere av denne artikkelen] (2016). Can we predict direct and correlated response to selection beyond the first generation?
• Hansen, Thomas F (2015). Fitness. I Losos, Jonathan (Red.), Oxford Bibliographies in Evolutionary Biology. Oxford University Press. ISSN 9780199941728.
• Kopperud, Bjørn Tore & Hansen, Thomas F (2015). The ungulate brain: A comparative analysis.
• Mayer, Christine & Hansen, Thomas F (2015). Genotype-Phenotype maps: Exploring evolvability and robustness by combining a multilinear framework with Boolean networks.
• Mayer, Christine & Hansen, Thomas F (2015). Modeling Genotype-Phenotype Maps by combining a multilinear model with Boolean Networks.
• Mayer, Christine & Hansen, Thomas F (2015). Genotype-Phenotype Maps: Exploring evolvability and robustness by combining a multilinear framework with Boolean networks.
• Hansen, Thomas F (2015). Forståelse og misforståelse av arvelighet gjennom historien. I Hessen, Dag Olav; Lie, Thore & Stenseth, Nils Christian (Red.), Mendels arv - Genetikkens æra. Gyldendal Norsk Forlag A/S. ISSN 978-82-05-45818-5. s. 45–79.
• Tarka, Maja; Pelabon, Christophe; Hansen, Thomas F & Sæther, Bernt-Erik (2015). Intralocus sexual conflict and the evolution of sexual dimorphism.
• Liow, Lee Hsiang & Hansen, Thomas F (2013). The Macroevolution Group: monkeys, horses, moss- and other animals (and plants).
• Labra, Antonieta; Voje, Kjetil Lysne; Seligmann, Hervé & Hansen, Thomas F (2011). Erratum bij_1599 237..238 Evolution of the third eye: a phylogenetic comparative study of parietal-eye size as an ecophysiological adaptation in Liolaemus lizards. Biological Journal of the Linnean Society. ISSN 0024-4066. 102(1), s. 237–238. doi: 10.1111/j.1095-8312.2010.01599.x.
• Pavlicev, Mihaela; Cheverud, James & Hansen, Thomas F (2010). The relationship between pleiotropy and evolvability. Integrative and Comparative Biology. ISSN 1540-7063. 50, s. E135–E135.
• Hessen, Dag Olav; Stenseth, Nils Christian & Hansen, Thomas F (2010). Anmeldelser: Menneskets vei. [Internett]. Tidsskrift for Den norske legeforening.
• Hansen, Thomas F (2009). Etter neodarwinismen: Hovedtrekk i evolusjonsteorien 1959-2009. I Hessen, Dag Olav; Lie, Thore & Stenseth, Nils Christian (Red.), Darwin - Verden ble aldri den samme. Gyldendal Litteratur. ISSN 9-788205-390348. s. 83–132.
• Hansen, Thomas F (2008). Macroevolutionary quantitative genetics? A comment on Polly (2008). Evolutionary Biology. ISSN 0071-3260. 35, s. 182–185. doi: 10.1007/s11692-008-9027-6.
• Fierst, Janna & Hansen, Thomas F (2008). The Genetic Architecture of Reproductive Isolation.

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