# BEAST 2

> phylogenetics software

**Wikidata**: [Q112030069](https://www.wikidata.org/wiki/Q112030069)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/BEAST_2)  
**Source**: https://4ort.xyz/entity/beast-2

## Summary
BEAST 2 is a software platform used for Bayesian evolutionary analysis and phylogenetic inference. It enables researchers to analyze molecular sequence data to understand evolutionary relationships among species. Written in Java, it supports complex models and is widely used in computational biology and genetics research.

## Key Facts
- Instance of: software, research software
- Programming language: Java
- Primary use: Phylogenetic analysis using Bayesian inference
- Related classes: Software, Java-based applications
- Available on Wikipedia in English and Spanish
- Sitelink count: 2 (limited external references recorded)
- Designed for scientific computing and evolutionary biology workflows

## FAQs
### Q: What is BEAST 2 used for?
A: BEAST 2 is used for conducting Bayesian phylogenetic analyses. Researchers use it to estimate evolutionary trees and parameters from genetic sequence data.

### Q: Is BEAST 2 free to use?
A: Yes, BEAST 2 is open-source software distributed under the GNU Lesser General Public License (LGPL), making it freely available for academic and commercial use.

### Q: What programming language is BEAST 2 written in?
A: BEAST 2 is written in Java, which allows it to run on multiple operating systems including Windows, macOS, and Linux.

## Why It Matters
BEAST 2 plays a central role in evolutionary biology by enabling scientists to reconstruct phylogenies—evolutionary trees that depict relationships among organisms—from molecular data such as DNA sequences. Its strength lies in its ability to incorporate complex evolutionary models and perform robust statistical inference through Markov chain Monte Carlo (MCMC) methods. As part of the broader BEAST ecosystem, BEAST 2 builds upon earlier versions with enhanced modularity, extensibility, and user interface tools like BEAUti for setting up analyses. The software has become essential in fields ranging from virology to conservation genetics, helping researchers trace disease outbreaks, assess biodiversity, and test evolutionary hypotheses.

## Notable For
- Being specifically designed for Bayesian phylogenetic inference
- Supporting highly customizable evolutionary models and MCMC sampling
- Featuring modular architecture allowing third-party extensions
- Built-in graphical tool integration via companion programs like Tracer and TreeAnnotator
- Cross-platform compatibility due to Java implementation

## Body
### Overview
BEAST 2 stands for "Bayesian Evolutionary Analysis Sampling Trees". It is the second major version of the BEAST software package, developed to improve flexibility and usability over its predecessor.

### Technical Details
- Language: Java
- License: LGPL (open-source)
- Platform support: Cross-platform (Windows, macOS, Linux)
- Core functionality: MCMC-driven Bayesian phylogenetic analysis
- Input format: XML configuration files typically created using BEAUti

### Ecosystem & Tools
BEAST 2 integrates with several supporting tools:
- **BEAUti 2**: Graphical application for creating XML input files
- **Tracer**: Tool for analyzing log files produced during MCMC runs
- **TreeAnnotator**: Summarizes posterior tree distributions
- **FigTree**: Visualizes annotated phylogenetic trees

These components together form a comprehensive environment for phylogenetic reconstruction and evolutionary modeling.

### Research Applications
The software is extensively used in academic research involving:
- Molecular dating of species divergence events
- Coalescent-based population genetics studies
- Phylogeographic reconstructions
- Estimation of selection pressures and substitution rates

Its modular design facilitates extension development, leading to numerous contributed packages hosted on the BEAST community repository.