The Ancient Tree of Life was born when Tang Wulin planted the Life Seed, given to him by the Ancient Golden Tree, in the deepest and center part of Sea God Lake. With the help of Tang Wulin and the absorption of the energy from the Abyssal Plane, it became taller than the Spirit Pagoda Headquarters stretching far beyond the sky. The trunk and roots of the tree can be seen from miles away. It was renamed the Eternal Tree. The Eternal Sky City was built on the crown of the tree. The Eternal Tree is the nucleus or core of the Douluo Planet.
In Soul Land 4, the life energy from the tree washes into Sea God Lake, filling the lake with life energy. People who drink the water of life will have their lifespan extended and feel refreshed. It also helps a spirit master raise their cultivation and strengthen their body. The tree maintains three sub-realms and it chooses the Life School Helmsman.
In SL4 chapter 1041, when Tang Xuanyu broke through to Spirit Emperor using the life energy from the Lake of Life, A'Bao helped promote the life stage of the Eternal Tree. As the tree evolves, it will become easier for it to collect life energy and more spirit masters will be able to reach the God Rank.
In SL4.5, the Eternal Tree evolved into the Divine Tree due to the influence of the Divine Realm.