DnaSP is a software package designed for analyzing DNA polymorphism data, offering several new modules and features. It can handle large data sets (up to 5 Mb per sequence), conduct extensive coalescent-based tests using Monte Carlo simulations, and perform genetic differentiation and gene flow analyses. The software also allows for the analysis of codon usage patterns and provides graphical outputs for easy visualization. Version 4 of DnaSP includes a user-friendly interface, supports multiple sequence file formats, and offers a range of statistical tests for neutrality, linkage disequilibrium, and population growth. The software is available for academic users and can run on various platforms, including Windows, Macintosh, Linux, and Unix.DnaSP is a software package designed for analyzing DNA polymorphism data, offering several new modules and features. It can handle large data sets (up to 5 Mb per sequence), conduct extensive coalescent-based tests using Monte Carlo simulations, and perform genetic differentiation and gene flow analyses. The software also allows for the analysis of codon usage patterns and provides graphical outputs for easy visualization. Version 4 of DnaSP includes a user-friendly interface, supports multiple sequence file formats, and offers a range of statistical tests for neutrality, linkage disequilibrium, and population growth. The software is available for academic users and can run on various platforms, including Windows, Macintosh, Linux, and Unix.