Taxonomists not only give names to organisms, they also place them in "family trees" based on a taxonomic system of relationships. This system is constantly revised to reflect new knowledge about organisms. The most current studies use the terms "tree of life" to refer to this evolutionary family tree, and phylogeny to refer to the evolutionary history of an organism—its path along the branches.
The value of having a "tree of life" system is that it allows us to see relationships between organisms and to make predictions. The Peabody Museum at Yale University does an excellent job of teaching about the tree of life and showing how it helps answer questions.
For instance, how does understanding how different species of snakes are related help you survive if you're bitten by a brown snake?
Click to find out: Travels in the Great Tree of Life
Why do some people who are sensitive to Poison Ivy have a similar reaction to the skin of mango fruits? Interactive popup. Assistance may be required.
Mangos and poison ivy have a similar phylogeny.
To help you better understand the tree of life, watch this video from Yale University.
Source: Discovering the Great Tree Of Life, YaleUniveristy, YouTube
Use your notes to describe the value of having a taxonomic system in which all species fit into a "tree of life."