![](https://cdn.kastatic.org/ka-perseus-images/f8ab932fdf2c660eb9cf9d35e8259e2d6a29f9b9.png)
To learn more https://www.khanacademy.org/science/biology/her/tree-of-life/a/building-an-evolutionary-tree
![](https://cdn.kastatic.org/ka-perseus-images/049df77f7f73db86b9e408ef7847923d7af40cec.png)
When we are building phylogenetic trees, traits that arise during the evolution of a group and differ from the traits of the ancestor of the group are called derived traits. In our example, a fuzzy tail, big ears, and whiskers are derived traits, while a skinny tail, small ears, and lack of whiskers are ancestral traits.
To learn more https://www.thoughtco.com/three-domain-system-373413