• Question: How did life begin? Did we start out as germs and bacteria's and evolved to what we are today? or was it something different completely.

    Asked by jesussatan on 28 Jun 2018.
    • Photo: Liza Selley

      Liza Selley answered on 28 Jun 2018:


      Yes, that’s what geneticists have shown – these scientists have traced the way that our genes and DNA have been passed on over the years as life evolved. As you suggest, it started with simple single-celled organisms which gradually made improvements to their physiology to help them survive in the environment they were in. Bacteria in water would have grown fins and gills then as water became more scarce, fish would have grown legs etc etc until the animals that we see today evolved. I think animals would look a lot different today if the dinosaurs hadn’t been wiped out! Large predators could have resulted in us having wings or being super tiny for example.

      There is an absolutely fantastic exhibition on this at the Natural History Museum if you are ever in London 🙂

    • Photo: Joanne Sharpe

      Joanne Sharpe answered on 28 Jun 2018:


      Yeah, that is what we think! We evolved from simple single cell organisms in the “primordial soup”. Every so often their DNA mutated to give them a survival advantage and these mutations became “fixed” in the population. Over millions of years, they evolved to be more and more complex, different species appeared, and eventually we arrived! Liza gives a great answer as to the order of how things happened 🙂

    • Photo: Claire Donald

      Claire Donald answered on 28 Jun 2018:


      Absolutely right! As Liza and Joanne have said we all began as single-celled organisms. We may have become much more complex beings now but we wouldnt exist without the help of other single -celled organisms. It is estimated that you are carrying around 10 times as many bacteria cells as you have body cells. They live on our skin and mucosal surfaces (like the mouth and gut). Most of the time our relationship with these bacteria is beneficial but if they get a bit carried away in numbers (with poor hygiene for example) we can get sick.
      Our cells also contain organelles called mitochondria which are the power houses of the cell, supplying it with energy. Interestingly, they have their own genetic information and are believed to once have been single-celled organisms in their own right. Millions of years ago, these mitochondrial bacteria were taken up by our larger cells where they have lived happily ever since.

    • Photo: Lauren Burns

      Lauren Burns answered on 28 Jun 2018:


      I think the three other scientists have explained this really well 🙂 Thanks all!!!

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