But, usually, we have fewer characters. Convergence of marsupial and placental mammals makes a good example. The last confirmed specimen died in the Hobart Zoo, Tasmania, in 1933. This is why we might want to use irrelevant characters as in the example given above. Cladistic Classification - Cladistics gives us an evolutionary tree called a cladogram.
Cladistics describes branching patterns by examining dervived homologous characters.
Normally, we need some reference point from which to distinguish which are apomorphic and which are symplesiomorphic characters. This is called the outgroup . Parsimony - Click here for an example showing how to make a cladogram from molecular data and the difference between a rooted and unrooted tree. This method is often known as traditional classification and combines consideration of overall similarity, as in phenetics, with branching, as in cladistics.