a member of the sister clade. However, for deeper phylogenetic analysis, less closely related taxa can be used. For example, Jarvis et al. (2014) used humans and crocodiles as outgroups while resolving the early branches of the avian phylogeny. In molecular phylogenetics, satisfying the second requirement typically means that DNA or protein sequences from the outgroup can be successfully aligned to sequences from the ingroup. Although there are algorithmic approaches to identify the outgroups with maximum global parsimony, they are often limited by failing to reflect the continuous, quantitative nature of certain character states. Character states are traits, either ancestral or derived, that affect the construction of branching patterns in a phylogenetic tree. Examples In each example, a phylogeny of organisms in the ingroup may be rooted by scoring the same character states for one or more members of the outgroup. See also Apomorphy, a derived trait of an organism Sister group, a group that may be closely related to an ingroup Plesiomorphy, an ancestral trait of an organism Primitive (phylogenetics), a term for ancestral traits References Phylogenetics Taxonomy (biology)