I stole this but believe it is true
maybe not the tree, per se, but the plant came first. Seeds are a late form of sexual reproduction. While plants have ways to reproduce asexually by sending out runners and such, seeds allowed for greater diversity by forming from the combined DNA of two parent plants. This diversity facilitates greater adaptability and resistance to threats. One must assume that a plant species arose that had never utilized seeds before but, through some mutation, produced seeds. For this plant, the use of seeds offered an advantage over it's peers and it thrived, produced more offspring, and dominated. A few million years later, viola, we have the seed bearing plants (trees) you see these days.
