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Laboratory of Evolutionary and Ecological Genomics

Research overview

We are broadly interested in how ecology affects the structure, function, and evolution of the genome, and its role in the development and evolution of complex phenotypes, particularly the sexual phenotype. 

This helps us understand the evolution of biological diversity and predict its response to environmental change.

Our integrative work spans classic ecology and evolutionary biology, eco-genomics, phylo-genomics, and epigenetics.

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Dr. Nicole Valenzuela 

Nicole ValenzuelaDr. Nicole Valenzuela
Department of Ecology, Evolution, and Organismal Biology
Iowa State University
Ames, IA 50011
(515) 294-1285

Recent research on Google Scholar 



Sex Determination

Evolution and Regulation of Developmental Networks

turtle embryo

Why do organisms vary so remarkably in the ways they produce males and females? Our work focuses on comparative evolutionary and ecological genomics related to the evolution of developmental pathways, particularly those that underlie the development of the sexual phenotype.


Sex Chromosomes and Genome Organization


What are the causes and consequences of chromosome evolution? We are studying (a) the evolution of sex chromosomes and the genes they contain, plus (b) the genome rearrangements responsible for changes in diploid number across turtles and their association with transitions in sex determination.


Iowa Turtle Army

The ITA provides an opportunity to Integrate undergraduate discovery-based learning through a service-learning activity that helps immerse biology undergraduates into the field and lab modules of the research projects conducted by the Valenzuela lab at Iowa State University.



TSD Book

It is fascinating that sexually-reproducing organisms employ such diversity of mechanisms to produce males and females, ranging from systems under strict genetic control (GSD) [such as highly dimorphic or undifferentiated sex chromosomes (XY, ZW)], to genetic systems susceptible to some environmental influences [such as haplo-dyploidy, polygenic systems, socially-induced sex reversals], to systems under strict environmental control dependent on biotic or abiotic factors.


Tree of Sex Database