Venki Ramakrishnan — The biggest of all perhaps is how life began. We still don’t

The biggest of all perhaps is how life began. We still don’t know how life started from a soup of chemicals – how molecules assembled, replicated, and managed to survive and evolve into incredibly complex life forms. We also don’t know how likely this was, and if we ever able to answer that, it will give us a better idea of whether we’re alone in the universe.