Field of biology that studies the evolutionary relationships between organisms. It includes the discovery of these relationships, and the study of the causes behind this pattern.

The reconstruction of the evolutionary history of a group of taxa or genes.

A branch of genetics that organizes species according to lines of descent from common ancestors.

In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e.g., species, populations). Also known as phylogenetic systematics, phylogenetics treats a species as a group of lineage-connected individuals over time. Phylogenetic taxonomy, which is an offshoot of, but not a logical consequence of, phylogenetic systematics, constitutes a means of classifying groups of organisms according to degree of evolutionary relatedness.