Outgroup
Main content start
OUTGROUP. Quercus lobata, Valley oak.
Old Page Mill Road, across from Frenchman’s Tower.
When inferring a phylogenetic tree of a group of taxa, an outgroup is a taxon that is not in the group of interest but that is included to facilitate the analysis. The outgroup is placed on one side of the root of the inferred tree, and the relationships among the taxa of interest are inferred on the other side of the root.
Photo: Noah Rosenberg, July 14, 2018