Transcript: In terms of our speculation about life in the universe, what can we conclude with all the information we have learned about the history of life on Earth. We have learned that life formed very early in extreme conditions. We’ve learned that carbon chemistry offers many different pathways for life processes. We’ve learned that the energy sources and chemical natures of life can be varied even though the biological basis of all organisms has a single common ancestor. We’ve learned that life radiated into many environments and that extremophiles have taken up conditions that match the extreme conditions on some of the planets in the solar system. We’ve learned that intelligence has been rare and slow to develop on Earth and that intelligence and technology are a rare outcome of natural selection.