The oldest known depictions of 'tree of life' motifs are found on vessels from Turkey's Domuztepe Mound in the southern province of Kahramanmaras, dating back to about 7,000 BCE. Archeologists believe the symbol spread from there in various ways. The culture or belief system surrounding the tree (related to a faith system and a burial tradition) expanded to the south and then became the most important factor in Sumerian civilization. There is also a similar tree in the Acadians, which is known a the 'eya tree' in Hittite documents in the 3000s BCE.
According to Dr. Halil Tekin who led the excavations, "the pine tree symbolizes life because it is a tree that never dies. The one we have found here is a tree with thorny leaves. This is why we believe it is a symbol of life."