Earth + Water = Mud
Earth + Fire = Lava
Air + Air = Pressure
Water + Water = Puddle
Puddle + Puddle = Pond
Pond + Pond = Lake
Lake + Lake = Sea
Sea + Earth = Primordial Soup
Primordial Soup + Energy = Life
Life + Earth = Land
Land + Life = Plant
Plant + Time = Tree
Tree + Tree = Wood
Wood + Wood = Woodin