The inclusion of the family tree shows how Grendel is naturally evil, as he is descended from the first evil human being that ever lived.
Although you did not present the text that your question refers to, when searching for questions like yours, I could see that you are referring to the family tree of Grendel, the antagonist of "Beowulf".
In this family tree, the author shows that Grendel:
This evil and sinful nature shows that whoever confronts Grendel, represents good, since Grendel is the pure representation of evil, from his lineage. In this way the author establishes the theme of "good versus evil."
It's important to remember that "Beowulf" is the epic tale that depicts the deadly battle between Grendel and Beowulf. You can find more information about this at the link below:
https://brainly.com/question/1830314?referrer=searchResults
