These are characters that are shared by a number of sequences due to retention of the ancestral character state. Synapomorphy These are characters that are shared by a group of sequences due to recentness of common ancestry. Those substitutions that do not change the identity of the encoded amino acid. This is an umbrella term to describe the processes that describe species. There are three disciplines which are united under this broad locution.
Systematic bias see Systematic error .
This is a facet of a dataset that will confound any tree reconstruction method. Situations such as long branch attraction and base-compositional bias are examples of systematic bias. Choose the first letter of your term.