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2017 Winter Lecture Series
The Epistasis-Environment Engine (EEE):
driving nonlinear relationships between genotype and phenotype in
microbes and beyond
C. Brandon Ogbunu, Ph.D.
Postdoctoral Fellow
Department of Organismic and Evolutionary Biology,
Harvard University
Thursday, February 23, 2017
1:00-2:30pm
CHS 13-105
The zeitgeist of modern biology can be defined by both abundant optimism and pervasive
skepticism. Underlying these disparate sentiments are varying degrees of confidence in
our ability to solve one of biology’s crowned jewels: A full disentanglement of the
relationship between genotype and phenotype. The age of genomics has offered much in
the way of this disentanglement, having identified thousands of individual gene networks,
genes, and single nucleotide polymorphisms that are associated with a range of
phenotypes across different species. Along with these breakthroughs, new questions
have emerged about the forces that foster nonlinearity between genotypic space and
phenotypic space. More specifically, we remain unclear about how the environment
sculpts the topography of certain genotype -phenotype maps, and why mutations have
“spurious functions” that lead to unexpected phenotypes.
In this presentation, I will discuss two forces that muddy our neat picture of genotype phenotype mapping, and consequently, the possibility of a deterministic biology: (i) the
ubiquitous effects of the environment and (ii) epistasis. I recast these forces into an
“engine” that drives nonlinear relationships between genotype and phenotype, and the
speed and direction of adaptive evolution. Using a combination of empirical, computational and mathematical approaches, I discuss how the epistasis-environment engine crafts
evolutionary dynamics in the evolution of antimicrobial resistance through promoting
nonlinearity in the genotype-phenotype map. I summarize the epistasis-environment
engine in light of its implications for the extended evolutionary synthesis and with regards
to its potential application to the public health realm. Lastly, I connect these analyses to
modern debates surrounding genetically modified organisms and other points of
intersection between science and society.
This event is sponsored by the Institute for Society & Genetics.
It is free and open to the public.