Online tools: Calculates the ratio of nonsynonymous (Ka) to synonymous (Ks) nucleotide substitution rates inorder to indicate selective pressures on genes, and can also be used to identify pairwise combinations of genes or branches of gene phylogenetic trees, where encoded proteins may have changed function.
Algorithms Implemented: NG (Jukes Cantor Models), LWL (JC-K2P-K2P) and MLWL (K2P-K2P-K2P)

Reference: Zhang Zhang, Jun Li, Xiao-Qian Zhao, Jun Wang, Gane Ka-Shu Wong, Jun Yu, KaKs_Calculator: Calculating Ka and Ks Through Model Selection and Model Averaging, Genomics, Proteomics & Bioinformatics, Volume 4, Issue 4, 2006, Pages 259-263, ISSN 1672-0229, DOI: 10.1016/S1672-0229(07)60007-2.
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