To determine evolutionary history and relationships of organisms, and create a system that will easily allow you to name and classify a new organism.

Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult.

While the goal of phylogeny is to reconstruct the evolutionary tree of life, taxonomy uses a hierarchical format to classify, name, and identify organisms.

From a macroevolutionary perspective, synapomorphies are important because they constitute the evidence for common ancestry, associated monophyletic groupings, and thus the historical relationships depicted in cladograms.

1. Step 1: Pick Organisms for Your Cladogram.
2. Step 2: Pick One Ancestral and One Derived Characteristic to Designate the Outgroup.
3. Step 3: Pick Derived Characteristics for the Ingroup (Part 1)
4. Step 4: Pick Derived Characteristics for the Ingroup (Part 2)
5. Step 5: Pick Derived Characteristics for the Ingroup (Summary)

The characteristics used to create a cladogram can be roughly categorized as either morphological (synapsid skull, warm blooded, notochord, unicellular, etc.) or molecular (DNA, RNA, or other genetic information). Prior to the advent of DNA sequencing, cladistic analysis primarily used morphological data.

Measuring homoplasy It is calculated by counting the minimum number of changes in a dataset and dividing it by the actual number of changes needed for the cladogram. A consistency index can also be calculated for an individual character i, denoted ci.