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Before there could be cells, there needed to be complex molecules and a host of elements to make them. The earliest known events of the universe generated only a few of the lightest elements: hydrogen, helium, and a little bit of lithium. Until the first stars formed and began fusing protons and neutrons into larger nuclei, the universe was devoid of heavier elements, including the carbon, nitrogen, and oxygen of which we are made. Other processes took these elements and bonded them into basic amino acids and other molecular precursors to life as we know it.
Biological evolution on our planet is thought to be nearly as old as the Earth, but the complexity that made it possible has been accumulating since time began.