'Line' in the Bible

This is the record of the family line of Adam. When God created humankind, he made them in the likeness of God.

Come, let's make our father drunk with wine so we can have sexual relations with him and preserve our family line through our father."

So in the morning the older daughter said to the younger, "Since I had sexual relations with my father last night, let's make him drunk again tonight. Then you go and have sexual relations with him so we can preserve our family line through our father."