The tilapiines were recognised by the
ichthyologist Ethylwynn Trewavas. mtDNA-based
phylogenies of tilapiines must be evaluated with caution, however, as they are usually close to, but do not represent the true evolutionary relationships of these fishes. The reason is that
hybridization within any one of these major lineages is known to usually produce fertile offspring, and might also do so between the lineages.
Gene pools in these fishes have been kept (largely) separate by behavioral cues for millions of years, but reproductive incompatibility has been far slower to evolve, like in many
Pseudocrenilabrinae (African cichlids). A small
sample size—one to a mere handful of specimens per
taxon—as is often used in molecular studies further acerbates the problem. As discussed below for the example of
mouthbreeding, nonmolecular data such as
morphology or
behavior have also turned out to be extremely prone to
homoplasies, not the least due to the small but ongoing
gene flow between evolutionarily quite distant gene pools. Essentially, most traditional and mtDNA-based phylogenetic hypothesis for tilapiines must be considered with a high degree of caution. This problem could be alleviated to some extent by using
nDNA sequences. Comparing these with the mtDNA data, hybridization effects could be discerned. Also, resolution of nDNA likely is still good enough to delimit the
clades that apparently exist in the "tilapiines" if numerous taxa and specimens are sampled. Researchers could then reanalyze morphological data to discover actual
autapomorphies. Evolution seems to run quickly in this group. Even the fast-evolving mtDNA sequences often are incapable of properly resolving interspecies relationships. The precise evolutionary history of some tilapiines may not be properly resolved with presently available methods, for the reasons discussed above. ==Diversity of breeding behaviour==