• Question: By what series of chemical reactions did atoms form the first living things?

    Asked by k9markred to Daniela, Hannah, Ian, Jono, Mark on 16 Jun 2013.
    • Photo: Ian Wilson

      Ian Wilson answered on 16 Jun 2013:

      Hi k9markred,

      You’ve been on fire with your questions haven’t you? 😀
      This one is, unfortunately, one without an answer yet. Basically, no-one knows for sure! There are LOADS of theories – take a look at this page to see the sheer number of them: http://en.wikipedia.org/wiki/Abiogenesis#Current_models

      Living things forming from non-living matter is called ‘abiogenesis’. From what I can tell (I had to Google this one!), about 4 billion years ago, loads of molecules and atoms and compounds etc existed in the Earth’s atmosphere and new ones were formed under extreme conditions. This might have been in reeeeaallly hot places or where lightning struck or from a high dose of UV light from the sun.

      At some point, a molecule was created that could make a copy of itself. It didn’t know it was doing it – it just so happened that its structure let it. And eventually, over a LONG time, other molecules joined with it, until they formed something we’d recognise as ‘life’. As for the chemical reactions involved, if we knew that, we’d be able to make organisms from scratch in a lab – now that’s a scary thought!

      Sorry that that’s so vague but, as far as I know, there are no definite answers here. Maybe one of the other scientists can be more useful?

      Ian

    • Photo: Mark Hodson

      Mark Hodson answered on 16 Jun 2013:

      Hi k9markred,

      that’s a fun question. As someone who studied rocks at University the theory I love about the origins of life is one suggested by a chemist at Glasgow called Cairns-Smith. He argues that tiny minerals called clay that form as rocks react on the earth’s surface are alive! You can read the details here http://en.wikipedia.org/wiki/Graham_Cairns-Smith
      Once you stop thinking that all life has to be carbon based and have DNA it’s not as mad as it might at first sound!

      If he is right then the chemical reactions involve water reacting with rocks!

      m

    • Photo: Jono Bone

      Jono Bone answered on 18 Jun 2013:

      Hi k9markred,

      I too find this a really interesting question, partly because there is not yet a known answer. Marks point is a really good one; I think to answer this question you really have understand what you mean by life because the first living things may have had very different biology to us.

      The link below gives you a great summary of the main theories, it’s well worth a read!!
      http://www.talkorigins.org/faqs/abioprob/originoflife.html

    • Photo: Hannah Brotherton

      Hannah Brotherton answered on 18 Jun 2013:

      Hi k9markred,
      The Miller–Urey experiment was an experiment that replicates the conditions of when Earth was created. This experiment allowed them to test how chemical reactions formed the origin of life. They found that the rays from the sun caused a chemical reaction with particles that already existed in the universe (like carbon and hydrogen, which come from the tails of comets and asteroids). The particles reacted so much to the rays of the sun they produced protein…….which makes up every living thing on earth. Being the perfect distance that Earth is from the sun, is very important in creating these chemical reactions…the distance is just right. This explains why other plants which are too close or too near the sun do not have (or not any more) living things.

      Even today, the sun allows us to live……with chemical reactions in the o-zone layer creating carbon dioxide which feeds the plants. The plants then give us oxygen which lets us to live.

      So our whole existence is to do with chemistry….and in a way chance….it was pure luck earth was the perfect distance from the sun, which lets all these chemical reactions happen. If the earth wasn’t at this distance, we might not exist. But the universe is so big..there might be another chance that another planet is the perfect distance from a sun somewhere else. Which means there could be life on another planet. Even more, maybe this planet formed years and years before earth and they could be more advanced than us? I love thinking like this….all these ifs and maybes, hows and whys. 😀

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