Because there is no indication of which node represents an ancestor, there is no direction of an evolutionary path in an unrooted tree.

Molecular phylogeny is a relatively new scientific discipline that involves the comparative analysis of the nucleotide sequences of genes and the amino acid sequences and structural features of proteins from which evolutionary histories and relationships, and in some cases also functions, can be inferred.

Topics include: Phylogenetics Basics, Gene Phylogeny Versus Species Phylogeny, & Forms of Tree Representation.