PAML (for Phylogenetic Analysis by Maximum Likelihood) is a package of programs for phylogenetic analyses of DNA or protein sequences using maximum likelihood. It is maintained by Ziheng Yang and distributed under the GNU GPL v3.

Before running any of the programs included in the PAML software, please go through the different sections of this Wiki, where a detailed explanation of how to install and run the programs is given. One of the main problems users face is related to data formatting. In that way, please make sure that you go through the section Data formatting in the PAML Wiki before running any PAML program and format your input data files and control files accordingly.

ANSI C source codes and executable files are distributed for UNIX, Linux, and Mac OS X (see the latest stable release available on this GitHub repository). PAML is not good for tree making, although it may be used to estimate parameters and test hypotheses to study the evolutionary process once you have reconstructed trees using other programs such as RAxML-NG, IQ-TREE, PAUP*, PHYLIP, PhyML, etc.

To download and install PAML software, please follow the next links in the wiki:

• Downloading and installing PAML
  • PAML for Linux
    • How to export paths in Linux
  • PAML for Mac OS X
    • How to export paths in Mac OS X
  • PAML for Windows 10 or later
    • How to export paths using the Windows Subsystem for Linux
  • Old compiled versions of PAML
    • PAML for Mac OS X
    • PAML for Windows 9x/NT/2000/XP/Vista 7
  • Graphical user interface: PAML-X

If you are a macOS user and you are experiencing issues such as "trace trap" or "segmentation fault" when running PAML programs, please download the dev branch and follow the installation instructions given in the section PAML for Mac OS X in the PAML Wiki.

The PAML Wiki is still under construction 🔧 -- we are slowly migrating the PAML documentation in PDF format to a more interactive and engaging tutorial!

In the meantime, you can access the following sections, which are also detailed in the PAML Wiki home section:

• Overview
  • PAML documentation
  • What PAML programs can do
  • What PAML programs cannot do
• Data formatting
  • Sequence data file format
    • Sequential and interleaved formats
      • Species/sequence names
      • Option G
      • Option G for codon sequences (codeml with seqtype = 1)
    • Site pattern counts
  • Tree file format and representations of tree topology
    • Parenthesis notation
    • Tree files produced by PAUP and MacClade
    • Branch or node labels
    • Divergence date symbol @
    • Branch representation of tree topology
• Substitution models
  • Nucleotide substitution models
  • Codon substitution models
    • Branch models
    • Site models
      • Suzuki and Gojobori’s (1999) method for detecting sites under positive selection
    • Branch-site models
    • Clade models
    • Mutation-selection models
  • Amino acid substitution models
• PAML programs
  • BASEML
  • BASEMLG
  • CODEML
  • Evolver
  • Infinitesites
  • MCMCtree
  • yn00

If you use PAML, please cite the following:

• Yang, Z (1997). PAML: a program package for phylogenetic analysis by maximum likelihood. Comput. Appl. Biosci. 13, 555-556.
• Yang, Z (2007). PAML 4: Phylogenetic Analysis by Maximum Likelihood. Mol. Biol. Evol. 24, 1586-1591.

If you use the PAML program MCMCtree, please cite the following papers if you have used/run...

• ... the approximate likelihood calculation to speed up analyses with phylogenomic datasets (calculating branch lengths, Hessian, and gradient):
  • dos Reis M and Yang Z (2011). Approximate likelihood calculation for Bayesian estimation of divergence times. Mol. Biol. Evol. 28, 2161-2172.
• ... Bayesian model selection analyses:
  • dos Reis M, et al. (2018). Using phylogenomic data to explore the effects of relaxed clocks and calibration strategies on divergence time estimation: Primates as a test case. Syst. Biol. 67, 594–615. Also, please cite the mcmc3r R package if you use it (see tutorial via this link).
• ... the models for continuous morphological characters implemented in MCMCtree:
  • Álvarez-Carretero S, et al. (2019). Bayesian estimation of species divergence times using correlated quantitative characters. Syst. Biol. 68, 967–986. Also, please cite the mcmc3r R package if you use it (see tutorial via this link).
• ... the protocol Bayesian Molecular Clock Dating Using Genome-Scale Datasets:
  • dos Reis M and Yang, Z (2019). Bayesian Molecular Clock Dating Using Genome-Scale Datasets. In: Anisimova, M. (eds) Evolutionary Genomics. Methods in Molecular Biology, vol 1910. Humana, New York, NY. You can also access this chapter and the code used throughout the protocol on the divtime GitHub repository maintained by Mario dos Reis.
• ... the protocol Environmental Microbial Evolution: Methods and Protocols:
  • dos Reis M (2022) In: Haiwei Luo (ed.) Environmental Microbial Evolution: Methods and Protocols. Methods in Molecular Biology, vol 2569. Humana, New York, NY. You can access the code used throughout the protocol on the microdiv GitHub repository maintained by Mario dos Reis.
• ... the Bayesian sequential-subtree (BSS) approach and/or the scripts to fit skew-t distributions to fossil calibrations:
  • Álvarez-Carretero S, et al. (2022) A species-level timeline of mammal evolution integrating phylogenomic data. Nature 602, 263–267. You can find the tutorial to reproduce these analyses on the mammals_dating GitHub repository maintained by Sandra Álvarez-Carretero.

If you use the PAML program CODEML, please cite the following papers if you have used/run...

• ... the protocol A Beginners guide to estimating the non-synonymous to synonymous rate ratio of all protein-coding genes in a genome:
  • Jeffares DC, Tomiczek B, Sojo V, dos Reis M (2015). A Beginners Guide to Estimating the Non-synonymous to Synonymous Rate Ratio of all Protein-Coding Genes in a Genome. In: Peacock, C. (eds) Parasite Genomics Protocols. Methods in Molecular Biology, vol 1201. Humana Press, New York, NY..
• ... the protocol Beginner's guide on the use of PAML to detect positive selection and/or the corresponding GitHub tutorial on the positive-selection repository:
  • Álvarez-Carretero S, Kapli P, Yang Z (2023). Beginner's guide on the use of PAML to detect positive selection, Mol Biol Evol, 40(4):msad041.. Remember to read the supplementary material where we discuss (i) analyses and checks you should carry out before running tests of positive selection with CODEML, (ii) gene tree VS species tree, and (iii) the usage of rooted and unrooted trees.

Changes and bug fixes until v4.10.1 were documented in the file doc/pamlHistory.txt. Changes in later versions have been documented for each release in the releases section of this GitHub repository.