Department of Biosciences, Rice University


Current position:

Assistant Professor in Ecology and Evolutionary Biology, Department of Biosciences, Rice University

Research Interests: 

I am interested in the processes that promote or constrain the evolution of new biological species. Examples of my research include:  (1.) understanding the role of adaptation via natural selection in the speciation process and (2.) exploring the genomic architecture associated with and mediating the evolution of new species. This work requires a multidisciplinary approach integrating natural history, manipulative field experiments, behavioral observations, and population genetics and genomics. Related interests include interdisciplinary research that harnesses genetic variation to address societal challenges, such as the rapid environmental detection of rare or invasive species (VIDEO).


PhD Biology, 2010, Vanderbilt University
Dissertation: Ecological speciation in Neochlamisus bebbianae leaf beetles

M.S. Biology, 2004, Texas State University - San Marcos
Thesis: Local adaptation in a gall-forming herbivore

B.S. Biology, 1999, University of Texas at Austin
Specialization: Evolution, Ecology, and Conservation


2015 -

Egan, S.P., G.R. Ragland, L. Assour, T.H.Q. Powell, G.R. Hood, S. Emrich, P. Nosil & J.L. Feder. 2015. Experimental evidence of genome-wide impact of ecological selection during early stages of speciation-with-gene-flow. Ecology Letters, in press.

Tadeo, E., J.L. Feder, S.P. Egan, H. Schuler,  M. Aluja, & J. Rull. 2015. Divergence and evolution of reproductive barriers among three allopatric populations of Rhagoletis cingulata across eastern North America and México. Entomologia Experimentalis et Applicataaccepted.

Egan, S.P., E. Grey, B. Olds, J.L. Feder, S. Ruggiero, C. Tanner, & D.M Lodge. 2015. Molecular detection of invasive species in ballast water using environmental DNA and  Laser Transmission Spectroscopy. Environmental Science & Technology 49: 4113–4121.  *link*

Gokham, V.E., J.R. Ott, & S.P. Egan. 2015. Chromosomes of Belonocnema treatae Mayr, 1881 (Hymenoptera: Cynipidae). Comparative Cytogenetics 9: 221-226.   *link*

Egan, S.P., G.R. Hood, & J.L. Feder. 2015. Chapter 69: 'Speciation-with-gene-flow' In: Encyclopedia of Evolutionary Biology. Elsevier Press, in press.

2014 -

Soria-Carrasco, V., Z. Gompert, A.A. Comeault, T.E. Farkas, T.L. Parchman, J.S. Johnson, C.A. Buerkle, J.L. Feder, J. Bast, T. Schwander, S.P. Egan, B.J. Crespi, & P. Nosil.  2014. Stick insect genomes reveal natural selection's role in parallel speciation. Science 344: 738-742. *link*      *Science NOW*     *Rice University Press Release*   *Faculty of 1000*  *Science Feature article*

Feder, J.L., P. Nosil, A. Wacholder, S.P. Egan, S. Berlocher, & S. Flaxman. Genome-wide congealing and rapid transitions across the speciation continuum during speciation with gene flow. Journal of Heredity 105: 810-820.  *link*

Ott, J.R. & S.P. Egan. 2014. Interspecific patterns of phenotypic selection do not predict intraspecific patterns. Journal of Evolutionary Biology 27: 214-219.  *link*

2013  -

Egan, S.P., G.R. Hood, G. DeVela, & J.R. Ott.  2013. Parallel patterns of morphological and behavioral variation among host-associated populations of two gall wasp species. PLoS ONE 8: e54690.      *link*     *press*

Egan, S.P., M. Barnes, C.-T. Hwang, A.R. Mahon, J.L. Feder, S. Ruggiero, C. Tanner, & D.L. Lodge. 2013. Rapid invasive species detection by combining environmental DNA with Light Transmission Spectroscopy. Conservation Letters 6: 402-409.    *link*    *press1*  *press2*    featured in 'Dispatches' section by Frontiers in Ecology and the Environment  *

Feder, J., S. Flaxman, S.P. Egan, A. Comeault, & P. Nosil. 2013. Geographic mode of speciation and genomic divergence. Annual Review of Ecology, Evolution, and Systematics 44: 73-97.   *link*

Feder, J.L., S.M. Flaxman, S.P. Egan, & P. Nosil. 2013. Hybridization and the buildup of genomic divergence during speciation. Journal of Evolutionary Biology 26: 261-266.    *link* 

Schuler, H., Bertheau, C., Egan, S.P., Feder, J.L., Riegler, M., Schlick-Steiner, B., Steiner, F., Johannesen, J., Kern, P., Koeppler, K., Arthofer, W., & Stauffer, C. 2013. Evidence for a recent horizontal transmission and expansion of Wolbachia from endemic Rhagoletis cerasi to invasive Rhagoletis cingulata in Europe. Molecular Ecology 22: 4101-4111.   *link*

Rull, J., M. Aluja, E. Tadeo, L. Guillen, S.P. Egan, M. Glover, & J.L. Feder. 2013. Distribution, host plant affiliation, phenology, and phylogeny of walnut-infesting Rhagoletis flies (Diptera: Tephritidae) in Mexico. Biological Journal of the Linnean Society 110: 765-779.  *link*

Saint Jean, G., S.P. Egan, W.L. Yee, & J.L. Feder. 2013. Genetic identification of an unknown Rhagoletis fruit fly (Diptera: Tephritidae) infesting Chinese crabapple: Implications for apple pest management. Journal of Economic Entomology 106: 1511-1515.  *link*    *press*

Feder, J.L., S.P. Egan, & P. Nosil. 2013. 'Speciation and Genome Evolution'. In: Princeton Guide to Evolution (J. Losos, ed.) Princeton University Press, New Jersey, in press.   *link*

Mahon, A.R., M.A. Barnes, F. Li, S.P. Egan, C.E. Tanner, S.T. Ruggiero, J.L. Feder, & D.M. Lodge. 2013. DNA-based species detection capabilities using Laser Transmission Spectroscopy. Journal of the Royal Society Interface 10 (78): 20120637.   *link*   

Hood, G.R. ,W.Yee, R. Goughnour, S. Sim, S.P. Egan, T. Arcella, G. St. Jean, T.H.Q. Powell, C. Xu & J.L. Feder. 2013. The geographic distribution of Rhagoletis pomonella (Diptera: Tephritidae) in the western United States: Introduced species or native population? Annals of the Entomological Society of America 106: 59-65.     *link*

Feder, J.L. & S.P. Egan. 2013. 'Sympatry and patterns of genetic differentiation in sympatry'. In: Encyclopedia of Genetics, 2nd edition (S. Malloy & K. Hughes, eds.). Elsevier Press.

2012  -

Egan, S.P., G.R. Hood, J.L. Feder, & J.R. Ott. 2012. Divergent host plant use promotes reproductive isolation among cynipid gall wasp populations. Biology Letters 8: 605-608.   *link*     *featured by The Earth Times*

Egan, S.P., G.R. Hood, & J.R. Ott. 2012. Testing the role of habitat isolation among ecologically divergent gall wasp populations.  International Journal of Ecology (special issue on Ecological Speciation), vol. 2012, Article ID 809897, 8 pgs.   *link*

Feder, J.L., S.P. Egan, & P. Nosil. 2012. The genomics of speciation-with-gene-flow. Trends in Genetics 28: 342-350  *link*    *featured cover article*

Reidenbach, K.R., D.E. Neafsey, C. Costantini, N. Sagon, F. Simard, G.J. Ragland, S.P. Egan, J.L. Feder, M. Muskavitch, & N. Besansky. 2012. Patterns of genomic differentiation between ecologically differentiated M and S forms of Anopheles gambiae in West and Central Africa. Genome Biology and Evolution 12: 1202-1212.     *link*

Hood, G.R., S.P. Egan, & J.L. Feder. 2012. Evidence for sexual isolation as a prezygotic barrier to gene flow between morphologically divergent species of Rhagoletis fruit flies. Ecological Entomology 37: 521-528.  *link*

Hood, G.R., S.P. Egan, & J.L. Feder. 2012. Interspecific competition and speciation in endoparasitoids. Evolutionary Biology 39: 219-230.  *link*

Rull, J., E. Tadeo, M. Aluja, L. Guillen, S.P. Egan, & J.L. Feder. 2012. Hybridization and sequential components of reproductive isolation between parapatric walnut-infesting sister species Rhagoletis completa and R. zoqui. Biological Journal of the Linnean Society 107: 886-898.    *link*

Lodge, D.M., C.R. Turner, C.L. Jerde, M.A. Barnes, L. Chadderton, S.P. Egan, J.L. Feder, A.R. Mahon, & M.E. Pfrender. 2012. Perspective: Conservation in a cup of water: estimating biodiversity and population abundance from environmental DNA. Molecular Ecology 21: 2555-2558.  *link*

Feder, J.L., S.P. Egan, & A.A. Forbes. 2012. Ecological adaptation and speciation: The evolutionary significance of habitat avoidance as a postzygotic reproductive barrier to gene flow. International Journal of Ecology (special issue on Ecological Speciation) vol. 2012, Article ID 456374, 15 pgs.    *link*    

Li, F., A.R. Mahon, M.A. Barnes, S.P. Egan, J.L. Feder, D.M. Lodge, C.-T. Hwang, R. Schafer, S.T. Ruggiero, & C.E. Tanner. 2012. 'DNA detection using Laser Transmission Spectroscopy'. IN: Nanotech 2012: Bio Sensors, Instruments, Medical, Environmental and Energy (Volume 3). Nano Science and Technology Institute.   *link*

Tanner, C., S. Ruggiero, F. Li, A.R. Mahon, M. Barnes, S.P. Egan, J.L. Feder, D.M. Lodge, C.-T. Hwang, & R. Shafer. 2012. DNA detection using Laser Transmission Spectroscopy. Bulletin of the American Physical Society, volume 57. 

2011 -

Egan. S.P., G.R. Hood, & J.R. Ott. 2011. Variable selection on gall size: differential contributions of individual host plants to population wide patterns. Evolution 65: 3543-3557.    *link*

Egan, S.P.E.M. Janson, C.G. Brown, & D.J. Funk. 2011. Postmating isolation and genetically variable host use in ecologically divergent host forms of Neochlamisus bebbianae leaf beetles. Journal of Evolutionary Biology 24: 2217-2229.   *link*

Ragland, G.J., S.P. Egan, J.L. Feder, S.H. Berlocher, & D.A. Hahn. 2011. Developmental trajectories of gene expression reveal regulatory candidates for diapause termination, a key life history transition in the apple maggot fly, Rhagoletis pomonella. Journal of Experimental Biology 214: 3948-3960.    *link*       *featured Inside JEB*

Funk, D.J., S.P. Egan, & P. Nosil. 2011. Isolation by adaptation in Neochlamisus leaf beetles: Host-related selection promotes neutral genomic divergence. Molecular Ecology 20: 4671-4682.   *link*

2006 - 2010 -

Egan, S.P. 2010. Ecological speciation in Neochlamisus bebbinae leaf beetles. PhD dissertation. Vanderbilt University, Nashville, TN.

Egan, S.P. & D.J. Funk. 2009. Ecologically dependent postmating isolation between sympatric 'host forms' of Neochlamisus bebbianae leaf beetles. Proceedings of the National Academy of Sciences 106: 19426 - 19431.    *link*        *featured in Exploration*

Egan, S.P., P. Nosil, & D.J. Funk. 2008. Selection and genomic differentiation during ecological speciation: isolating the contributions of host-association via a comparative genome scan of Neochlamisus bebbianae leaf beetles. Evolution 62: 1162-1181.   *link*

Nosil, P., S.P. Egan, & D.J. Funk. 2008. Divergent selection plays multiple roles in generating heterogeneous genomic differentiation between walking-stick ecotypes. Evolution 62: 316-336.   *link*

Egan, S.P. & J.R. Ott. 2007. Host plant quality and local adaptation determine the distribution of a gall-forming herbivore. Ecology 88: 2869-2879.   *link*

Egan, S.P. & D.J. Funk. 2006. Individual advantages to ecological specialization: insights on cognitive constraints from three conspecific taxa. Proceedings of the Royal Society, B 273: 843-848.    *link*

Other contributions -

Wetherington, R. & S.P. Egan. 2013. 'Don't let the science of evolution lose to the politics of teaching it'Op-Ed piece on teaching mainstream science in public schools - Published in the Austin American-Statesman (link), Houston Chronicle (link), Fort Worth Star-Telegram (link), Corpus Christi Caller-Times (link), and the San Antonio Express-News (link).

Manuscripts in review -

Reynolds, R.J., G. de los Campos, S.P. Egan, & J.R. Ott. Modeling heterogeneity among fitness functions using random regression, in revision.

Arcella, T., S.B. Sim, W.L. Yee, G.R. Hood, T.H.Q. Powell, D. Schwarz, S.P. Egan, R.B. Goughnour, J.J. Smith, & J.L. Feder. Hybridization and the spread of the Apple Maggot Fly, Rhagoletis pomonella (Diptera: Tephritidae), in the Northwestern United States, in revision.

Ragland, G., Meyers, P., Doellman, M., Hood, G., Egan, S.P., Powell, T.H.Q., Hahn, D., Nosil, P. & J. Feder. A test of genomic modularity among life history adaptations promoting speciation-with-gene-flow, in review.

Dougherty, M.M., E.R. Larson, M.A. Renshaw, C.A. Gantz, S.P. Egan, D.M. Erickson & D.M. Lodge. Environmental DNA (eDNA) detects the invasive rusty crayfish (Orconectes rusticus) at low abundances, in review.

Hood, G.H., A.A. Forbes, T.H.Q. Powell, S.P. Egan, G. Hamerlinck, J.J. Smith & J.L. Feder. Sequential speciation and the multiplicative origin of community diversity, in review.

Manuscripts in preparation -

Egan, S.P., G.R. Hood, & J.L. Feder. Ecological divergence promotes reproductive isolation across the genus of Rhagoletis, in prep

Funded grants: 

Johnson, C. (PI) and S.P. Egan (coPI). Environmental DNA detection of the critically endangered Houston toad (Bufo houstonensis). Houston Zoo Staff Conservation Fund (2013). 

Egan, S.P. (PI), J.L. Feder (coPI), D.M. Lodge (coPI), C. Tanner (coPI), S. Ruggiero (coPI), J. Tank (coPI), S. Howard (coPI), & E. Rosi-Marshall (coPI). Monitoring the dispersal of genetically engineered organisms and their byproducts using Light Transmission Spectroscopy. United States Department of Agriculture - Biotechnology Risk Assessment Research Grants - $500,000 (2013-2015).  *ND press release*    *Article in ND Observer*

Egan, S.P. (PI), D.M. Lodge (coPI), J.L. Feder (coPI), C. Jerde (coPI), M. Pfrender (coPI), C. Tanner (coPI), & S. Ruggiero (coPI). Environmental DNA (eDNA) longevity and relationship to abundance of diverse taxa. Environmental Protection Agency - Great Lakes Restoration Initiative - $600,000 (2012-2014).  *EPA summary*   *ND Press Release*   *WSBT-TV news story*  *InsideIndianaBusiness article*  

Feder, J. (PI), S.P. Egan (coPI), J. McLachlan (coPI), C. Linn Jr. (coPI),  & A. Forbes (coPI). Does sequential speciation amplify biodiversity across trophic levels? – Collaborative Research – National Science Foundation – Evolutionary Processes – $1.1 million (2012-2014).   *NSF summary*     *ND Press Release*

Ragland, G. (PI), S.P. Egan (coPI), J. Feder (coPI), & D. Hahn (coPI). Testing for functional and genetic independence of rapidly evolving life cycle components in the apple maggot, a model for seasonal adaptation – Collaborative Research – National Science Foundation – Organism-Environment Interactions – $1.0 million total / $512,981 ND portion (2013-2015)

Contact Information:

Mailing address:

BioSciences  MS-140
Rice University 
GRB W200 
6100 Main street, 
Houston, Texas 77005, USA

email -