• Question: Personally, how do you believe life on Earth began?

    Asked by rhooper821 to Ben, Dave, Ed, Sam, Susana on 18 Jun 2013.
    • Photo: Benjamin Hall

      Benjamin Hall answered on 18 Jun 2013:


      Spontaneously.

      It’s been demonstrated in a laboratory that conditions similar to what the earth would have been like billions of years ago can lead to the production of biological molecules from non-biological molecules.

      So we know that the building blocks of life can assemble spontaneously.

      Where we go from here is open to lots of debate. There are so many different hypotheses and it would be really difficult to test them, mainly because we don’t have a time machine!

      What we do know is that the simple biological molecules DID form more complex molecules which were capable of undergoing replication and selection.

    • Photo: David Briggs

      David Briggs answered on 18 Jun 2013:


      Very. Very. Very slowly.

      We know that the planet is about 4 billion years old. Our best hypothesis is called the “RNAworld” hypothesis – this says that small, self-replicating molecular machines (ribozymes) formed from basic chemical building blocks billions of years ago in the “primordial soup”. We know this is possible because we can replicate those conditions in the lab and make complex chemicals this way.

      Over lots, and lots, and lots of years, these ribozymes got more and more sophisticated, and formed cells. These cells eventually evolved into the massive and wide variety of life you see every day! Amazing, isn’t it?

    • Photo: Sam Horrell

      Sam Horrell answered on 19 Jun 2013:


      As David and Ben have already said it all happened by chance in the primordial soup (or ooze, whichever you prefer) with really basic organisms. Then evolution over however many billions of years has developed all the life you can see around you. And all the microorganisms you can’t see.

      I don’t subscribe to any of the religious creation stories personally.

    • Photo: Susana Teixeira

      Susana Teixeira answered on 19 Jun 2013:


      I tend to follow a principle that says the simplest explanation is usually the correct one. The primordial soup (see Dave’s answer) is fairly simple and has been shown to be possible: before life on Earth there were enough carbon-based ingredients and activating agents to create the reactions that generate nucleic acids, from which a whole generation of other molecules essential for life can come, given enough time. And time there was! 🙂

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