This is a graduate-level course in phylogenetics, emphasizing primarily maximum likelihood and Bayesian approaches to estimating phylogenies, which are genealogies at or above the species level. A primary goal is to provide an accessible introduction to the theory so that by the end of the course students should be able to understand much of the primary literature on modern phylogenetic methods and know how to intelligently apply these methods to their own problems. The laboratory provides hands-on experience with several important phylogenetic software packages (PAUP*, IQ-TREE, RevBayes, BayesTraits, and others) and introduces students to the use of remote high performance computing resources to perform phylogenetic analyses.

Semester: Spring 2026
Lecture: Tuesday/Thursday 11:00-12:15 (Paul O. Lewis, office hours Tu 1-2 or by appointment in Gant W421)
Lab: Thursday 1:25-3:20 (Analisa Milkey, office hours: Mo 3-4, Fr 1-2 in Gant W420)
Room: Torrey Life Science (TLS) 181, Storrs Campus
Text: Lewis, P. O. 2024. Getting Rooted in Bayesian Phylogenetics (unfinished, but some chapters are ready)

Schedule

Warning: This schedule will most likely change quite a few times during the semester.

Date Lecture topic Lab/homework
Tuesday Jan. 20 Trees and optimality criteria Homework 1
Thursday Jan. 22 Search strategies, consensus trees Lab 1 Using the HPC cluster
Tuesday Jan. 27 Snow Day: no class Python Primer,Homework 2
Thursday Jan 29 Agreement subtree, Mono-,para-,polyphyly,parsimony, and NJ, Split Decomposition Lab 2 Searching
Tuesday Feb. 3 Substitution models Homework 3
Thursday Feb. 5 Maximum likelihood criterion Lab 3 Estimating parameters using likelihood
Tuesday Feb. 10 Rate heterogeneity Individual Meetings
Thursday Feb. 12 Simulation Lab 4 Simulating sequence data
Tuesday Feb. 17 Bootstrapping, Bayes’ Rule Homework 4
Thursday Feb. 19 Markov chain Monte Carlo (MCMC) Lab 5 Using R to explore probability distributions
Tuesday Feb. 24 Snow Day: no class Homework 5
Thursday Feb. 26 MCMC (cont.) Lab 6 Maximum likelihood analyses with IQ-TREE
Tuesday Mar. 3 Priors Homework 6
Thursday Mar. 5 Model selection Lab 7 RevBayes 1
Tuesday Mar. 10 Coalescence Individual Meetings
Thursday Mar. 12 Species trees Lab 8 RevBayes (continued)
Tuesday Mar. 17 SPRING BREAK SPRING BREAK
Thursday Mar. 19 SPRING BREAK SPRING BREAK
Tuesday Mar. 24 Discrete morphological models Homework 7
Thursday Mar. 26 Evolutionary Correlation; Star Tree Paradox Lab 9 RevBayes with discrete morphological data
Tuesday Mar. 31 Independent Contrasts; PGLS (start) Homework 8
Thursday Apr. 2 PGLS (cont.); Phylogenetic signal Lab 10 BayesTraits
Tuesday Apr. 7 OU model, Relaxed clocks Homework 9
Thursday Apr. 9 Fossilized Birth Death Process; Confidence vs. credible intervals; Dirichlet Process Priors** Lab 11 Divergence Time Estimation with RevBayes
Tuesday Apr. 14 Dirichlet Process Priors; Heterotachy and Covarion) Individual Meetings
Thursday Apr. 16 Codon, amino acid, and stem-loop models Lab 12 Species tree estimation with SVDQuartets
Tuesday Apr. 21 Inferring introgression/hybridization Homework 10
Thursday Apr. 23 Diversification Lab 13 Comparative methods and diversification in R
Tuesday Apr. 28 TBA no homework assignment
Thursday Apr. 30 Species delimitation and information Lab 14 Plotting trees in R with ggtree

Index to major topics

Index for 2026

Literature cited

Literature cited in 2026

Grading

Grading info

Books (and book chapters) on phylogenetics

This is a list of books that you should know about (most recent listed first), but none are required texts for this course. I will distribute chapters from a book I am writing that will serve as the textbook for this course.

LJ Revell and LJ Harmon. 2022. Phylogenetic comparative methods in R. Princeton University Press. ISBN:978-0-691-21903-5

C Scornavacca, F Delsuc, and N Galtier. 2020. Phylogenetics in the Genomic Era. No commercial publisher (open access book) ISBN:978-2-9575069-0-3, hal-02535070v3

L Harmon. 2019. Phylogenetic comparative methods. (Version 1.4, released 15 March 2019). Published online by the author.

AR Ives 2018. Mixed and phylogenetic models: a conceptual introduction to correlated data. Leanpub

AJ Drummond and RR Bouckaert. 2015. Bayesian evolutionary analysis with BEAST. Cambridge University Press. ISBN:978-1-139-09511-2

Z Yang. 2014. Molecular evolution: a statistical approach. Oxford University Press. ISBN:978-0-199-60261-0

LZ Garamszegi. 2014. Modern phylogenetic comparative methods and their application in evolutionary biology: concepts and practice. Springer-Verlag, Berlin. ISBN:978-3-662-43549-6 (Well-written chapters by current leaders in phylogenetic comparative methods.)

DA Baum and SD Smith. 2013. Tree thinking: an introduction to phylogenetic biology. Roberts and Company Publishers, Greenwood Village, Colorado. ISBN:978-1-936-22116-5 (This book is a useful companion volume for this course, introducing the methods in a very accessible way but also providing lots of practice interpreting phylogenies correctly.)

BG Hall. 2011. Phylogenetic trees made easy: a how-to manual. (4th edition). Sinauer Associates, Sunderland. ISBN:978-0-878-93606-9 (A guide to running some of the most important phylogenetic software packages.)

P Lemey, M Salemi, and AM Vandamme. 2009. The phylogenetic handbook: a practical approach to phylogenetic analysis and hypothesis testing. (2nd edition). Cambridge University Press, Cambridge, UK. ISBN:978-0-511-81904-9] (Chapters on theory are paired with practical chapters on software related to the theory.)

J Felsenstein. 2004. Inferring phylogenies. Sinauer Associates, Sunderland. ISBN:978-0-878-93177-4 (Comprehensive overview of both history and methods of phylogenetics.)

R Page and E Holmes. 1998. Molecular evolution: a phylogenetic approach. Blackwell Science. ISBN:978-0-865-42889-8 (Very accessible pre-Bayesian-era introduction to the field.)

D Hillis, C Moritz, and B Mable. 1996. Molecular systematics. (2nd ed.). Sinauer Associates, Sunderland. ISBN:978-0-878-93282-5 (Still a very valuable compendium of pre-Bayesian-era phylogenetic methods.)

DL Swofford, GJ Olsen, PJ Waddell, and DM Hillis. 1996. Chapter 11: Phylogenetic inference. Pages 407-514 in Molecular Systematics (D. M. Hillis, C. Moritz, and B. K. Mable, eds.). Sinauer Associates, Sunderland, Massachusetts. ISBN:978-0-878-93282-5 (Excellent reference for pre-Bayesian phylogenetics; original description of the SOWH topology test)