The universe started with only hydrodgen, heliun and lithium present as gases. But they were smashed together to make carbon with berylium formed on the way. Then the heavier elements were also formed within the crushing gravity of large stars. When those stars exploded the heavier elements were spread all over the universe. Fred Hoyle is the guy who worked this out. Now computers are refining the concept:-http://www.scientificamerican.com/article.cfm?id=hoyle-state-primordial-nucleus-behind-elements-life&WT.mc_id=SA_CAT_physics_20121207