Thomas J. DeWitt

Associate Professor
Department of Ecology & Conservation Biology
Texas A&M University
College Station, TX 77843-2258 USA

Fax (979) 845-4096, E-mail

   Ph.D. (Ecology, Evolution & Behavior) Binghamton University (SUNY), 1995
   M.A. (Ecology, Evolution & Behavior) Boston University, 1991
   Naturalist Ecologist Training Program, University of Michigan, 1990
   B.Sc. (Biology) Grand Valley State University, 1987

Research interests:
Ecological mechanisms of evolutionary differentiation, Ecomorphology, Phenotypic plasticity, Biometry and shape analysis, Quantitative and molecular genetics, Ecological and evolutionary theory

   Excel Biometry – WFSC 670
   Population Genetics – GENE 612
   Behavioral Ecology – WFSC 622
   Introduction to Bioenvironmental Science – BESC 201
   Water and Bioenvironmental Science – BESC 320
   Fish Ecophysiology – WFSC 448

Some recent undergraduate research posters:
      2015 BURS project - Briana
      2015 BURS project - Kaylee
      2015 BURS project - Chris

TJ DeWitt & SM Scheiner, Eds. (2004)
Phenotypic Plasticity. Functional and Conceptual Approaches Oxford University Press (ISBN 0195138961).
This book presents a conceptual overview of the large and flourishing field of phenotypic plasticity.
It covers the history, current practice and theory of the field and provide syntheses with related fields such as behavioral ecology, physiology, and coevolution.
[Read back cover] [Table of contents] [Chapter 1--FREE!]

Some research highlights:
   (1) Evolutionary diversification of fish body shape (see example poster)
    (2) Inducible defenses in snails with functionally diverse predators (detail)
    (3) Performance (functional ecology) studies with aquatic animals (example poster), amphibians (example poster), snails
    (4) Theoretical models of evolution in stochastic environments (detail)
    (5) Mating behavior of simultaneous hermaphrodites (cartoon)
    (6) Theoretical and geometric morphometrics

Favorite links!


DeWitt TJ (2022)
  A simplified perspective on the index of spatial autocorrelation.
    Landscape Ecology 37:657–661. doi 10.1007/s10980-021-01393-6. Author PDF

DeWitt TJ, Prestridge HL (2022)
  On the need for antibiotics to reduce subject losses and biases in experiments with aquatic molluscs.
    Malacologia 64: 303–307. doi Author PDF

DeWitt TJ, Troendle NJ, Mateos M, Mauricio R (2022)
  Population genetics and independently replicated evolution of predator-associated burst speed ecophenotypy in mosquitofish
    Heredity. doi 10.1038/s41437-021-00487-w. Author PDF
      Data @ Dryad Data

Harrison K, Tarone A, DeWitt TJ, Medina R (2022)
  Predicting the occurrence of host-associated differentiation in parasitic arthropods: A quantitative literature review
    Entomologia Experimentalis et Applicata 170:5–22. doi 10.1111/eea.13123.   PDF

DeWitt TJ, Fuentes JI, Ioerger TR, Bishop MP (2021)
  Rectifying I: three point and continuous fit of the spatial autocorrelation metric, Moran’s I, to ideal form
    Landscape Ecology 36: 2897–2918. doi 10.1007/s10980-021-01256-0. Author PDF

Mays JR, DeWitt TJ, Dharampal P, Andrus CFT, Findlay RH (2019)
  Frequent habitat migration, phenotypic plasticity, and residual ecophenotypy revealed by isotope-based natal habitat inference in bluegill sunfish, Lepomis macrochirus
    Evolutionary Ecology Research 20(6):xx-xx. Online early version at

DeWitt TJ, McCarthy TM, Washick DL, Clark AB, Langerhans RB (2018)
  Predator avoidance behaviour in response to turtles and its adaptive value in the freshwater snail Planorbella campanulata
    Journal of Molluscan Studies 84: 266-274. doi 10.1093/mollus/eyy025.   PDF

Chinchilla-Ramírez M, Borrego EJ, DeWitt TJ, Kolomiets MV, Bernal JS (2017)
  Maize seedling morphology and defence hormone profiles, but not herbivory tolerance, were mediated by domestication and modern breeding
    Annals of Applied Biology 170:315-332. doi 10.1111/aab.12331

Bucksch A, Atta-Boateng A, ... DeWitt TJ, ... Chitwood DH (2017)
  Morphological plant modeling: unleashing geometric and topological potential within the plant sciences
    Frontiers in Plant Science 8:900. doi 10.3389/fpls.2017.00900   PDF

Smith HL, DeWitt TJ (2017)
  The northern fluted point complex: technological and morphological evidence of adaptation and risk in the late Pleistocene-Early Holocene Arctic
    Archaeological and Anthropological Sciences. doi 10.1007/s12520-016-0335-y PDF

DWitt TJ (2016)
  Expanding the phenotypic plasticity paradigm to broader views of trait space and ecological function
    Current Zoology 62:463–473. doi 10.1093/cz/zow085   (open access)

Carlson KB, de Ruiter DJ, DeWitt TJ, McNulty K, Carlson K, Tafforeau P, Berger LR (2016)
  Developmental simulation of the adult cranial morphology of Australopithecus sediba.
    South African Journal of Science 112: 20160012. doi 10.17159/sajs.2016/20160012 (open access)

Santamaria C, Mateos M, DeWitt TJ, Hurtado L (2016)
  Constrained body shape among highly genetically divergent allopatric lineages of the supralittoral isopod Ligia occidentalis (Oniscidea)
    Ecology and Evolution 6:1537–1554. doi 10.1002/ece3.1984 (open access)

Timm-Davis LL, DeWitt TJ, Marshal CD (2015)
  Divergent skull morphology supports two trophic specializations in otters (Lutrinae).
    PLOS ONE 10(12):e014326. doi 10.1371/journal.pone.0143236 (open access)

Kim D, DeWitt TJ, Costa CSB, Kupfer JA, McEwan RW, Stallins JA (2015)
  Beyond bivariate correlations: three-block partial least squares illustrated with vegetation, soil, and topography
    Ecosphere 6(8):art135. doi 10.1890/ES15-0074.1 (open access)

Davis KM, ...DeWitt TJ, Riley DG (2015)
  Digital quantification of eye pigmentation of cattle with white faces.
    Journal of Animal Science 93:3654-3660. doi 10.2527/jas2014-8786   PDF

Smith HL, Smallwood AM, DeWitt TJ (2014)
  A geometric morphometric exploration of Clovis fluted point shape variability.
    In: Smallwood AM, Jennings TA (Eds.), Clovis: On the Edge of a New Understanding, Texas A&M University Press.

Cope JL, Hammett AJM, Kolomiets EA, Forrest AK, Golub KW, Hollister EB, DeWitt TJ, Gentry TJ, Holtzapple MT, Wilkinson HH (2014)
  Evaluating the performance of carboxylate platform fermentations across diverse inocula originating as sediments from extreme environments
    Bioresource Technology 155:388–394. doi 10.1016/j.biortech.2013.12.105   PDF

Brophy JK, de Ruiter DJ, Athreya S, DeWitt TJ (2014)
Quantitative morphological analysis of bovid teeth and implications for paleoenvironment reconstruction of Plovers Lake, Gauteng Province, South Africa
Journal of Archaeological Science 41:376–388. doi 10.1016/j.jas.2013.08.005   PDF

Santamaria CA, Mateos M, Taiti S, DeWitt TJ, Hurtado LA (2013)
  A complex evolutionary history in a remote archipelago: phylogeography and morphometrics of the Hawaiian endemic Ligia isopods
    PLOS ONE 8: e85199. 10.1371/journal.pone.0085199 (open access)
      Data @ Dryad Data

Dávila-Flores AM, DeWitt TJ, Bernal JS (2013)
  Facilitated by nature and agriculture: performance of a specialist herbivore improves with host-plant life history evolution, domestication, and breeding
    Oecologia 173:1425-1437. PDF

De Ruiter DJ, DeWitt TJ, Carlson KB, Brophy JK, Schroeder L, Ackermann RR, Churchill SE, Berger LR (2013)
  Mandibular remains support taxonomic validity of Australopithecus sediba.
    Science 340:1232997. PDF SOM

Chaves-Campos J, Coghill LM, Al-Salamah MA, DeWitt TJ, Johnson SG (2012)
  Field heritabilities and lack of correlation of snail shell form and antipredator function estimated using Bayesian and maximum likelihood methods
    Evolutionary Ecology Research 14:743–755. PDF

Langerhans RB, DeWitt TJ, Gifford ME, García-Bedoya D, Domínguez-Domínguez O (2012)
  Gambusia quadruncus (Cyprinodontiformes: Poeciliidae): a new species of mosquitofish from east-central Mexico
    Journal of Fish Biology 81:1514-1539. PDF

Ginter CC, DeWitt TJ, Fish FE, Marshall CD (2012)
Fused traditional and geometric morphometrics demonstrate pinniped whisker diversity.
PloS One 7(4):e34481. (open access)

Ruehl CB, Shervette V, DeWitt TJ (2011)
  Replicated shape variation between simple and complex habitats in two estuarine fishes
    Biological Journal of the Linnean Society 103:147–158   PDF

Tobler M, DeWitt TJ, Schlupp I, García de León FJ, Herrmann R, Feulner PGD, Tiedemann R, Plath M (2008)
  Toxic hydrogen sulfid and dark caves: Phenotypic and genetic divergence across two abiotic environmental gradients in Poecilia mexicana
    Evolution 62:2643-2658. PDF

Johnson JB, Burt DB, DeWitt TJ (2008)
  Form, function, fitness—pathways to survival.
    Evolution 62:1243-1251.     PDF [2008 ASIH Poster]

McEachran JD, DeWitt TJ (2008)
  A new livebearing fish, Heterandria tuxtlaensis, from Lake Catemaco, Veracruz, Mexico (Cyprinodontiformes: Poeciliidae)
    Zootaxa 1824:45-54 PDF

Ruehl CB, DeWitt TJ (2007)
  Trophic plastcity and foraging performance in red drum, Sciaenops ocellatus (Linnaeus)
    Journal of Experimental Marine Biology & Ecology 349:284-294   PDF

Langerhans RB, Chapman LJ, DeWitt TJ (2007)
  Multiple phenotypes, multiple environmental gradients: complex phenotype-environment associations in an East African cyprinid
    Journal of Evolutionary Biology 20:1171–1181   PDF   [2008 ASIH Poster]

Chapman LJ, DeWitt TJ, Tzaneva V, Paterson J (2007)
  Interdemic variation in gill morphology of a eurytopic African cichlid
    Proceedings of the 9th International Symposium: Fish Physiology, Toxicology, and Water Quality.
      EPA publication 600R07010:209-225   PDF

Dayton GH, Saenz D, Baum KA, Langerhans RB, DeWitt TJ (2005)
  Body shape, burst speed and predator susceptibility of larval anurans
    Oikos 111:582-591   PDF

Langerhans RB, Layman CA, DeWitt TJ (2005)
  Male genital size reflects a tradeoff between attracting mates and avoiding predators in two livebearing fish species
    Proceedings of the National Academies of Science USA 102:7618-7623. PDF

Ruehl CB, DeWitt TJ (2005)
  Trophic plasticity and fine-grained resource variation in populations of western mosquitofish, Gambusia affinis
    Evolutionary Ecology Research 7:801–819 PDF

Langerhans RB, Layman CA, Shokrollahi AM, DeWitt TJ (2004)
  Predator-driven phenotypic diversification in Gambusia affinis
    Evolution 58:2305–2318. PDF

Langerhans RB, DeWitt TJ (2004)
  Shared and unique features of evolutionary diversification
    American Naturalist 164:335-349. PDF

DeWitt TJ, Scheiner SM, Eds. (2004)
  Phenotypic Plasticity. Functional and Conceptual Approaches
    New York: Oxford University Press.
      Chapter 1: DeWitt TJ, Scheiner SM (2004) Phenotypic Variation From Single Genotypes: A Primer   PDF
      Chapter 7: DeWitt TJ, Langerhans RB (2004) Integrated solutions to environmental heterogeneity: Theory of multimoment reaction norms
      Chapter 13: Scheiner SM, DeWitt TJ (2004) Future research directions

Langerhans RB, Layman CA, Langerhans AK, DeWitt TJ (2003)
  Opposite habitat-based divergence in two fishes within a tropical blackwater river
    Biological Journal of the Linnean Society 80:89-98. PDF

DeWitt TJ, Langerhans RB (2003)
  Multiple prey traits, multiple predators: keys to understanding complex community dynamics
    Journal of Sea Research 49:143-155. PDF

Langerhans RB, DeWitt TJ (2002)
  Plasticity constrained: Overgeneralized induction cues cause maladaptive phenotypes
    Evolutionary Ecology Research 4:857-870. PDF

DeWitt TJ, Robinson BW, Wilson DS (2000)
  Functional diversity among predators of a freshwater snail imposes an adaptive tradeoff for shell morphology
    Evolutionary Ecology Research 2:129-148. PDF

DeWitt TJ, Sih A, Hucko JA (1999)
  Trait compensation and cospecialization in a freshwater snail: Size, shape and antipredator behaviour
    Animal Behaviour 58:397-407. PDF

DeWitt TJ, Sih A, Wilson DS (1998)
  Costs and limits of phenotypic plasticity
    Trends in Ecology & Evolution 13:77-81. PDF

DeWitt TJ, Yoshimura J (1998)
  The fitness threshhold model: Random environmental change alters adaptive landscapes
    Evolutionary Ecology 12:615-626. PDF

DeWitt TJ (1998)
  Costs and limits of phenotypic plasticity: Tests with predator-induced morphology and life history in a freshwater snail
    Journal of Evolutionary Biology 11:465-480.; PDF

DeWitt TJ (1997)
  Optimizing clutch size in birds (Correspondence)
    Trends in Ecology & Evolution 12:443. PDF

DeWitt TJ (1996)
Gender contests in a simultaneous hermaphrodite snail: A size-advantage model for behaviour
Animal Behaviour 51:345-351. PDF

DeWitt TJ (1993)
  Nest-site preference in male fathead minnows, Pimephales promelas
    Canadian Journal of Zoology 71:1276-1279   PDF

DeWitt TJ (1991)
nbsp; Mating behavior of the freshwater pulmonate snail, Physa gyrina
nbsp; nbsp; American Malacological Bulletin 9:81-85.   PDF