David Brewster

I am a PhD candidate at Harvard.

Research

My research focuses on evolutionary dynamics in structured populations, with broader applications to complex systems.

Info

[ Headshot | CV | Google Scholar | PubMed | GitHub ]

E-mail: [first name initial] [last name] [at] g [dot] harvard [dot] edu

News

• 2026-04-21 — Invited talk on Maintaining diversity in structured populations at Interdisciplinary Transformation University Austria (IT:U Linz)
• 2026-03-31 — Gave lecture on Evolution in structured populations for MATH 243
• 2026-03-28 — Invited talk on Maintaining diversity in structured populations at American Mathematical Society (AMS) Spring Eastern Meeting @ Boston College
• 2026-03-20 — I am now an affiliate of the Institute for Quantitative Social Science (IQSS) at Harvard
• 2026-03-19 — Invited talk on Mixed birth-death and death-birth updating in structured populations at Oxford statistical genetics seminar
• 2026-03-18 — Poster presentation on Classifying perturbations in complex network dynamics at Citadel | Citadel Securities PhD Summit in London, UK
• 2026-02-25 — Our paper Speciesism in AI: Evaluating Discrimination Against Animals in Large Language Models was accepted to Nature Communications!
• 2026-02-17 — Gave lecture on The replicator equation + direct reciprocity for MATH 243
• 2025-11-10 — Our paper Mixed birth-death and death-birth updating in structured populations was accepted to Innovations in Theoretical Computer Science (ITCS) 2026
• 2025-11-06 — Gave lecture on Time in structured populations for MATH 242
• 2025-11-04 — Gave lecture on Evolutionary timescales for MATH 242

Teaching

• Teaching Fellow for MATH 242/243: Mathematical Biology-Evolutionary Dynamics — Fall 2023 – Spring 2026
• Teaching Fellow for COMPSCI 226r: The Theory of Algorithmic Fairness — Spring 2024
• Teaching Fellow for COMPSCI 224: Algorithms for Data Science — Fall 2023
• Course Assistant for CS 374: Intro to Algorithms and Models of Computation — Fall 2020, Spring 2021
• Course Assistant for CS 126: Software Design Studio — Fall 2017, Spring 2019, Fall 2019, Spring 2020

Papers

1. Mixed updating in structured populations
   David Brewster, Yichen Huang, Michael Mitzenmacher, and Martin Nowak
   Innovations in Theoretical Computer Science (ITCS), 2026
   
   • Slides from invited talk at Oxford statistical genetics seminar
   • Talk by Yichen at Innovations in Theoretical Computer Science (ITCS) 2026
   • Demo
   • Code from paper
2. Large language models exhibit speciesist bias against animals
   Monika Jotautaitė, Lucius Caviola, David Brewster, and Thilo Hagendorff
   Accepted to Nature Communications, 2026
   
   • Thilo's talk on previous work at re:publica 2023
   • Overview of paper
   • Code from paper
3. Maintaining diversity in structured populations
   David Brewster, Jakub Svoboda, Dylan Roscow, Krishnendu Chatterjee, Josef Tkadlec, and Martin Nowak
   PNAS Nexus, 2025
   
   • Slides from invited talk at The Graduate University for Advanced Studies, SOKENDAI
   • Girish's demo
   • Code from paper
4. Fixation times on directed graphs
   David Brewster, Martin Nowak, and Josef Tkadlec
   PLOS Computational Biology, 2024
   
   • Slides from contributed talk at Max Planck Institute for Evolutionary Biology - Evolutionary Graph Theory Workshop
   • Slides from contributed talk at Workshop on Modeling and Applications of Evolutionary Game Theory
   • Slides from invited talk at UIUC Algebra-Geometry-Combinatorics Seminar
   • Code from paper
5. Proper elements of Coxeter groups
   with József Balogh and Reuven Hodges
   European Journal of Mathematics, 2024
   • Code from paper
6. Channel capacity of the ribosome
   Daniel Inafuku, Kay Kirkpatrick, Onyema Osuagwu, Qier An, David Brewster, and Mayisha Zeb Nakib
   Physical Review E, 2023
   
   • Article by UIUC Physics Research Highlights
   • Code from paper
7. Proper permutations, Schubert geometry, and randomness
   with Reuven Hodges and Alexander Yong
   Journal of Combinatorics, 2022
   
   • Slides by Alex from ICERM: Geometry and Combinatorics from Root Systems
   • Talk by Alex at ICERM: Geometry and Combinatorics from Root Systems