Table 2. Unique substitutions and coevolutionary clusters formed by these sites in snake COI.
| Alethinophidian Snakes | Blind Snakes | |||||||||||||
| Coevolutionary Clusters | Site | Non-snake Tetrapods | A. piscivorus | O. okinavensis | P. slowinskii | D. semicarinatus | A. granulatus | B. constrictor | C. ruffus | P. regius | X. unicolor | L. dulcis | T. reticulatus | |
| 7 | 26 | A | S | S | S | S | S | S | S | S | S | A | S | |
| 1 | 35 | L | I | I | I | I | I | I | I | V | I | L | M | |
| 1 | 37 | I | M | M | M | M | M | M | M | M | M | I | V | |
| 1 | 54 | Y | F | F | F | F | Y | F | F | F | F | Y | Y | |
| 89 | A | T | T | A | A | A | A | A | A | A | A | A | ||
| 7 | 108 | S | A | A | A | A | A | A | A | A | A | A | S | |
| 174 | P | K | K | K | K | K | A | A | A | P | K | P | ||
| 8 | 194 | L | M | M | M | M | M | M | M | M | M | L | L | |
| 5 | 205 | G | A | A | A | A | A | A | A | A | A | A | A | |
| 5 | 231 | Y | F | F | F | F | F | F | F | F | F | Y | F | |
| 3 | 256 | H | S | S | S | S | S | S | S | S | S | H | H | |
| 3 | 258 | V | I | I | I | I | I | I | I | I | I | I | I | |
| 4 | 266 | E | N | N | N | N | N | N | N | N | N | E | E | |
| 4 | 267 | P | T | T | T | T | T | T | T | T | T | P | P | |
| 272 | G | S | S | S | S | S | S | S | S | S | S | S | ||
| 8 | 281 | G | A | A | A | A | A | A | A | A | A | A | S | |
| 286 | I | V | V | V | V | V | V | V | V | V | V | I | ||
| 6 | 299 | V | I | I | I | I | I | I | I | I | I | V | V | |
| 6 | 301 | T | S | S | S | S | S | S | S | S | S | T | T | |
| 353 | L | M | M | M | M | M | M | M | M | M | L | L | ||
| 438 | R | R | R | G | R | R | R | R | R | R | R | R | ||
| 2 | 443 | Y | F | F | F | F | F | F | F | F | F | Y | Y | |
| 2 | 447 | Y | F | F | F | F | Y | F | F | F | F | F | F | |
Amino acid replacements in snake COI amino acid sequences from the conserved consensus amino acid in tetrapods are shaded in gray. Spatially clustered sites that experience apparent coevolutionary replacements are numbered.