Fig. 5
From: Crossing fitness valleys via double substitutions within codons
Similarity between the ancestral, intermediate, and final amino acids for different classes of double substitutions. The DAS metric measures the difference in amino acid similarity/distance for the original➔final vs. original➔intermediate codons. DAS = AA similarity/distance (original➔final) − average AA similarity/distance (original➔intermediate). Three comparisons, using different amino acid similarity/distance matrices, are shown. a NN double substitutions. b SN double substitutions. c NS double substitutions