Todd Streelman

Todd Streelman

Professor and Chair

Streelman grew up in Chestertown Md, where he developed a keen interest in the outdoors. He graduated with a BS in Biology from Bucknell University. While there, he attended a semester (plus one cold winter-mester) at the Marine Biological Laboratory in Woods Hole Massachusetts — where a chance encounter with Les Kaufman, Karel Liem, a few jars of pickled fish and a dental X-ray technician led to his lifelong love of cichlids. Streelman won the Pangburn Scholar-Athlete award (lacrosse) at BU. As a PhD student with Stephen Karl, Streelman developed approaches to identify, clone and sequence multiple, independent single-copy nuclear loci to reconstruct accurate phylogenies for cichlid fishes and their relatives. These phylogenies changed perspective about how these species groups evolved, and allowed new and improved inference about the evolutionary history of key ecological traits. Multi-locus phylogenies are now the standard in the field. 

As a postdoc in Tom Kocher’s lab and then a young investigator at Georgia Tech, Streelman worked on the first unbiased quantitative genetic (QTL) studies in Malawi cichlids, some of the first such studies in evolutionary systems. In particular, work showed that adaptive features of the cichlid jaw and the striking orange-blotch color polymorphism had a simple genetic basis.  

Streelman was an Alfred P. Sloan Foundation Postdoctoral Fellow, an Alfred P. Sloan Foundation Faculty Research Fellow and a NSF CAREER Awardee.  

Over the past two decades as an independent investigator, with support from the NSF, NIH and the Human Frontier Science Program, Streelman’s group has pioneered genomic and molecular biology approaches in the Malawi cichlid system to solve problems difficult to address in traditional model organisms. Major projects include (i) tooth and taste bud patterning and regeneration; (ii) the underpinnings of complex behavior; and (iii) developmental diversification of the face and brain.  

Generally, we are captivated by context-dependent traits like development and behavior because they must be executed in space and time with exquisite control. We analyze and manipulate genomes and development in multiple species of Malawi cichlids, spanning divergence in embryonic/adult traits and behavior – and collaborate with folks studying these same traits in zebrafish, mouse and human. In 2014, Streelman helped to coordinate a large effort to sequence the genomes of five East African cichlids, including one from Lake Malawi. This was a landmark for our research community and has recast attention to genome-wide approaches. We are motivated by the prospect to dissect evolutionary change with genetic and cellular precision.  

In his free time, Streelman likes mountaineering, skipping rocks and pickling.


Office Location:
EBB 3007



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    Georgia Institute of Technology

    School of Biological Sciences
    Research Focus Areas:
  • Molecular Evolution
  • Neuroscience
  • Additional Research:

    Researchers in the Streelman lab use the cichlid fish model to address fundamental questions in ecology and evolution. We are fascinated by context-dependent processes like embryonic development, the regeneration of organs and complex behavior. Context-dependency is interesting because it reveals new rules of biological systems that are not necessarily operational during homeostasis. For instance, recent results suggest that stem-like cells in the brain may tune the evolution of male social behavior. 

    We raise cichlids from Lake Malawi in custom fish facilities at Georgia Tech. We invent automated assays to quantify behavior, we sequence genomes and the transcriptomes of cells, and we collaborate with computational scientists, engineers and colleagues working in zebrafish, mouse and human. Members of the lab are keen to learn new things by working together, compelled by mechanism and comparative approaches.

    Research Affiliations: Regenerative Engineering and Medicine (REM), Center for Integrative Genomics

    IRI Connection: