Systematics is the division of Biology where scientists work to determine an evolutionary tree that relates all extant and extinct species. To do this organismal characters that differ among species must be identified. Choose all of the following statements which accurately portray this effort. Check All That Apply

1. Common ancestry often provides shared features which place organisms into the appropriate position of the evolutionary tree,
2. Similarities always reflect common ancestry, this is termed homology.
3. Both birds and mammals are homeotherms which illustrates homoplasy, i. e. that they are each others closest relatives.
4. Organismal characters are identified by observing patterns of similarity among organisms in various possible areas. These include anatomical structures as well as nucleic acid and protein sequence data