People

Joseph Thornton, PhD

My lab studies the mechanisms by which protein functions evolve. We do this by phylogenetically reconstructing the histories of ancient proteins and then synthesizing, manipulating, and experimentally characterizing their biological functions and physical properties.



This kind of work is powerful and fun — and possible at all — because we are a diverse group of evolutionary biologists, biochemists, biophysicists, computational biologists, geneticists, and molecular biologists, all working together and freely mingling our expertise, techniques, and ideas.



We address classical and recent questions about the nature of evolutionary processes, such as: How do complex molecular systems evolve? Does evolution proceed by a few large-effect or many small-effect mutations? Does epistasis shape the evolutionary process and make the pathways and outcomes of evolution contingent on chance events? Is evolution reversible? How does the architecture of biological systems shape the evolutionary process? How did evolution produce those architectures in the first place?



Evolutionary analysis can also help address core questions in biochemistry, biophysics, and molecular biology. Why do proteins have the particular architectures that they do? How does that architecture itself evolve? What structural and genetic mechanisms cause functions to differ between members of protein families? How do molecular machines, allostery, and molecular interfaces evolve? Are proteins’ physical properties always optimized for their functions, and if not, why not? Can history explain why particular proteins are subject to interference by particular drugs and pollutants? We have found that detailed reconstruction of proteins’ histories helps us to understand why and how their present-day descendants work as they do today.

Columbia University
New York
Postdoc
2012

Columbia University/ American Museum of Natural History
Ph.D - Biological Sciences
2000

The simplicity of protein sequence-function relationships.
The simplicity of protein sequence-function relationships. Nat Commun. 2024 Sep 11; 15(1):7953.
PMID: 39261454

Imperfect symmetry facilitated the evolution of specificity and high-order stoichiometry in vertebrate hemoglobin.
Imperfect symmetry facilitated the evolution of specificity and high-order stoichiometry in vertebrate hemoglobin. bioRxiv. 2024 Jul 26.
PMID: 39091803

Frequent transitions in self-assembly across the evolution of a central metabolic enzyme.
Frequent transitions in self-assembly across the evolution of a central metabolic enzyme. bioRxiv. 2024 Jul 07.
PMID: 39005358

Epistasis facilitates functional evolution in an ancient transcription factor.
Epistasis facilitates functional evolution in an ancient transcription factor. Elife. 2024 May 20; 12.
PMID: 38767330

The simplicity of protein sequence-function relationships.
The simplicity of protein sequence-function relationships. bioRxiv. 2024 Feb 07.
PMID: 37732229

The simplicity of protein sequence-function relationships.
The simplicity of protein sequence-function relationships. bioRxiv. 2023 Sep 05.
PMID: 37732229

Evolutionary Shortcuts via Multinucleotide Substitutions and Their Impact on Natural Selection Analyses.
Evolutionary Shortcuts via Multinucleotide Substitutions and Their Impact on Natural Selection Analyses. Mol Biol Evol. 2023 07 05; 40(7).
PMID: 37395787

Simple mechanisms for the evolution of protein complexity.
Simple mechanisms for the evolution of protein complexity. Protein Sci. 2022 11; 31(11):e4449.
PMID: 36107026

Epistatic drift causes gradual decay of predictability in protein evolution.
Epistatic drift causes gradual decay of predictability in protein evolution. Science. 2022 05 20; 376(6595):823-830.
PMID: 35587978

Molecular and structural basis of olfactory sensory neuron axon coalescence by Kirrel receptors.
Molecular and structural basis of olfactory sensory neuron axon coalescence by Kirrel receptors. Cell Rep. 2021 11 02; 37(5):109940.
PMID: 34731636

View All Publications

Steenbock Distinguished Lecturer in Biochemistry
University of Wisconsin
2016

Distinguished Alumni Lectureship
University of Queensland School of Biochemistry
2016

Guggenheim Foundation Fellowship
2014

Hans Falk Award
National Institute for Environmental Health Sciences
2014

Richard Jones Investigator Award
Oregon Medical Research Foundation
2010

Early Career Investigator
Howard Hughes Medical Institute
2009

U.S. Presidential Early Career Award for Scientists and Engineers
2007

Alfred P. Sloan Foundation Research Fellow
2006

CAREER Award
National Science Foundation
2006

Distinguished University Lecturer in Environmental Sustainability
Carnegie-Mellon University
2002