| Hybridization, the interbreeding of diagnosably divergent species, is a major focus in evolutionary studies. |
| Comparison of 2400 wings of 25 Drosophilid species shows that wing shape is quite conservative within the group, but that almost all taxa are diagnosably different from one another. |
| There was no molecular character support for the M. m. calita, M. m. cotorra, and M. m. monachus subspecies, while the Bolivian M. m. luchsi was monophyletic and diagnosably distinct. |
| Black scoter and common scoter have diagnosably distinct vocalisations. |
