Evolution, Ecology & Organismal Biology

David Reznick

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Office: (951) 827-5820
Fax: (951) 827-4286
209 University Lab Bldg.
Email: gupy@ucr.edu

David Reznick, Distinguished Professor

Ph.D., University of Pennsylvania, 1980


My general interest is in studying the process of evolution by natural selection from an experimental perspective and testing evolutionary theory in natural populations.  I primarily work on guppies from the Caribbean Island of Trinidad.  Guppies are found in high and low predation environments that differ in the species of predators that guppies co-occur with. Guppies from high predation environments experience much higher mortality rates.  High mortality is associated with earlier maturity, a higher rate of investment of resources in reproduction, and the production of more and smaller offspring.  All of these differences have a genetic basis.  Mortality rates can be manipulated by either introducing guppies from high predation localities into sites from which they and their predators had previously been excluded by waterfalls, thus lowering mortality rates, or by introducing predators into low predation sites over barrier waterfalls, thus increasing mortality rates.  Such experiments have shown that life histories evolve as predicted by theory and in a fashion that is consistent with the earlier comparative studies. They have also shown that evolution by natural selection can be remarkably fast, on the order of four to seven orders of magnitude faster than inferred from the fossil record.  I am currently studying the consequences of contemporary evolution, specifically the ways in which ecology and evolution interact with one another in real time (eco-evo interactions) in this same system.  This research includes four replicate introductions of guppies from high predation localities into previously guppy free low predation localites.  We are following the introduced populations with monthly mark-release-recapture censuses, reconstructing the pedigrees of the evolving populations with DNA samples collected from every individual and tracking the impact of guppies on their ecosystem.  Collaborators include Tim Coulson (Oxford), Joseph Travis (Florida State) and Ron Bassar (Williams).  In a second research program I am studying the evolution of placentas in the fish family Poeciliidae and am using the natural diversity in the family (including at least 8 independent origins of placentas) as a forum for evaluating predictions of intergenomic conflict theory.

Dr.  Reznick participates in IDEA, the UCR Institute for the Development of Educational Applications, serves as the UCR co-Associate Director of NERE, the Network for Experimental Research on Evolution, and is director of the EEOB "Sustain Life" GAANN fellowship program.


Representative Publications

  • Bassar, R. D., T. Simon, W. Roberts, J. Travis, D. N. Reznick.  The evolution of coexistence: Reciprocal adaptation promotes the assembly of a simple community.  Evolution 71: 373- 385. (2017)

  • Reznick, D. N., A. I. Furness, R. W. Meredith and M. Springer.  The origin and biogeographic diversification of fishes in the family Poecliidae. Plos One 12: Article number: e0172546. (2017)

  • Reznick, D. N.  Hard and soft selection revisited: how evolution by natural selection works         in the real world.  J. of Heredity 107: S3-S14. (2016)

  • Ghalambor, C. K., K. L. Hoke, E. W. Ruell, E. K. Fischer, D. N. Reznick and K. A. Hughes.  Non-adaptive plasticity potentiates rapid adaptive evolution of gene expression in nature.  Nature 525: 372-375. (2015)
  • Travis, J., D. N. Reznick, R. D. Bassar, A.  Lopez-Sepulcre, R. Ferriere and T. Coulson.  Do eco-evo feedbacks help us understand nature? Answers from studies of the Trinidadian guppy.  Advances in Ecological Research 50: 1-40. (2014)

  • Pollux, B. J. A., R. W. Meredith, T. Garland, M. S. Springer, and D. N. Reznick.  The evolution of the placenta drives a shift in sexual selection in livebearing fish.  Nature 513: 233-236. (2014)

  • Reznick, D. N.  A critical look at reciprocity in ecology and evolution: introduction to    the symposium.  American Naturalist 181: S1-S8. (2013)

  • Bassar, R. D., A. Lopez-Sepulcre, D. N. Reznick and J. Travis.  Experimental evidence for density-dependent regulation and selection on Trinidadian guppy life histories.  American Naturalist 181: 25-38. (2013).

  • Reznick, D. N.,  R. D. Bassar, J. Travis and H. F. Rodd.  Life history evolution in guppies VIII: The demographics of density regulation in guppies (Poecilia reticulata). Evolution 66: 2903-2915. (2012).
  • Walsh, M. R. and D. N. Reznick.  Experimentally induced life-history evolution in a killifish in response to the introduction of guppies.  Evolution 65: 1021-1036. (2011)
  • Bassar, R. D., M. Marshall, A. Lopez-Sepulcre, R. Zandona, S. K. Auer, J. Travis, C. M. Pringle, A. S. Flecker, S. A. Thomas, D. F. Fraser and D. N. Reznick.  Local adaptation in Trinidadian guppies alters ecosystem processes.  Proceedings of the National Academy of Sciences 107: 3616-3621.(2010)
  • Pollux, B. J. A., M. Pires, A. I. Banet and D. N. Reznick.  Evolution of placentas in the fish family Poeciliidae: An empirical study of macroevolution.  Annual Reviews of Ecology and Systematics 40: 271-289. (2009)
  • Reznick, D. N. and R. E. Ricklefs.  Darwin's bridge between microevolution and macroevolution.  Nature 457: 837-842.  (2009)
  • Walsh, M. and D. N. Reznick. Interactions between the direct and indirect effects of predators determine life history evolution in a killfish.  Proceedings of the National Academy of Sciences 105: 594-599. (2008).
  • Ghalambor, C. K., J. K. McKay, S. P. Carroll and D. N. Reznick.  Adaptive versus non-adaptive phenotypic plasticity and the potential for adaptation to new environments.  Functional Ecology 21: 394-407. (2007)
  • Olendorf, R., F. H. Rodd, D. Punzalan, A. E. Houde, C. Hurt, D. N. Reznick and K. A. Hughes.  Frequency-dependent survival in natural guppy populations.  Nature 441: 633-636. (2006)
  • Reznick, D. N., M. J. Bryant, and D. Holmes.  The evolution of senescence and post-reproductive lifespan in guppies (Poecilia reticulata). PLOS-Biology 4: 136-143.  (2006)
  • Reznick, D. N. and C. Ghalambor.  Can commercial fishing cause evolution?  Answers from guppies.  Can. J. of Fisheries and Aquatic Sciences 62: 791-801. (2005)
  • Reznick, D. N., Bryant, M., Roff, D. A., Ghalambor, G. and Ghalambor, D. E. Effects of extrinsic mortality on the evolution of senescence in guppies (Poecilia reticulata). Nature 431: 1095-1099.  (2004)
  • Reznick, D. N., M. Mateos, and M. S. Springer. Independent origins and rapid evolution of the placenta in the fish genus PoeciliopsisScience 298, 1018-1020 (2002).
  • Reznick, D. N., M. J. Bryant, and F. Bashey. r- and K-selection revisited: The role of density, resources, and environmental fluctuations in life-history evolution. Ecology 83, 1509-1520 (2002).
  • Reznick, D. N. and C. Ghalambor. The population ecology of contemporary adaptation: What empirical studies reveal about the conditions that promote adaptive evolution. Genetica112/113, 183-198 (2002).
  • Reznick, D. N., L. Nunney and A. Tessier. Big houses, big cars, superfleas and the costs of reproduction. Trends in Ecology and Evolution 15, 421-425 (2000).
  • Reznick, D.  N., Shaw, F.  H., Rodd, F.  H.  & Shaw, R.  G.  Evaluation of the rate of evolution in natural populations of guppies (Poecilia reticulata).  Science 275, 1934-1937 (1997). 
  • Reznick, D.  N., Butler M.  J., I., Rodd, F.  H.  & Ross, P.  Life history evolution in guppies (Poecilia reticulata).  6.  Differential mortality as a mechanism for natural selection.  Evolution 50, 1651-1660 (1996). 
  • Reznick, D.  A., Bryga, H.  & Endler, J.  A.  Experimentally induced life-history evolution in a natural population.  Nature 346, 357-359 (1990). 

Reznick, D. N.  2009.  The Origin Then and Now: An Interpretive Guide to the Origin of

            Species.  Princeton University Press. 

Recent Teaching
  • Biology 5c, Introductory Ecology and Evolution
  • Biology 105, Evolution
  • Biology 161A, Functional Morphology of the Vertebrates
  • Biology 216, The Theory of Evolution

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