Gene Trees and Species Trees

Genetic lineages can be viewed as evolving along the branches of a species tree. The species tree describes the divergence of an ancestral species into descendant species. The gene tree describes the particular pattern of descent seen at a specific site in the genome. In a common representation of gene tree evolution along a species tree (e.g. Maddison 1997), the gene tree is depicted as a narrow tree of lineages nested inside wider branches that represent the species tree—much like the “tree” of electrical conduits on this coast live oak.

Photo: Noah Rosenberg, December 24, 2019