Phylogenesis is the biological process by which a taxon (of any rank) appears.

In biology, a taxon (plural taxa; back-formation from taxonomy) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established.

The science that studies phylogenesis is called phylogenetics.

These terms may be confused with the term phylogenetics, the application of molecular - analytical methods (i.e. molecular biology and genomics), in the explanation of phylogeny and its research.

Phylogenetic relationships are discovered through phylogenetic inference methods that evaluate observed heritable traits, such as DNA sequences or overall morpho-anatomical, ethological, and other characteristics.

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