Traditionally, karyology has been considered when determining species status.

Evidence based on the fossil record, serology, karyology, behavior, anatomy, and reproduction reflect closer affinities with Procyonidae than Ursidae.

In particular, plants are in-depth investigated from different viewpoints (morphology, systematics, taxonomy, biochemistry, karyology, anatomy, etc.), and at various levels of organisation, from cells up to communities.