• Question: Right in the beginning, what were humans made of?

    Asked by sophiewest to Adam, Catherine, Karen, Leila, Nazim on 14 Mar 2012.
    • Photo: Adam Stevens

      Adam Stevens answered on 14 Mar 2012:

      I don’t know what you mean in the beginning…

      But I’ll give it a shot.

      All life on earth is basically composed of 4 things – hydrogen, oxygen, carbon, and nitrogen (and a tiny bit of other stuff, like phosphorus in our DNA).

      We say that life is carbon based because almost all the molecules that make up our body and the molecules that make our bodies go are built around carbon, which is very good at making complex molecules that are able to do particular jobs. The hydrogen and oxygen in our bodies is mostly in the form of water, but oxygen is useful for chemical reactions.

      So the first living thing, whether it emerged from primordial goo (probably not) or developed at an undersea vent (probably) would have been made up of these four things. If that’s true then what living things are made of hasn’t really changed in billions of years.

      Therefore humans have always been made of the same stuff 🙂

    • Photo: Catherine Rix

      Catherine Rix answered on 14 Mar 2012:

      The question of how life first started is a really interesting one. We think that the first life forms were probably unicellular – this means that they were only made of a single cell, whereas modern humans are made of trillions of cells. How the first ever cell was made and how we came about from these single celled life forms is an area that scientists are very interested in. When we look for life on other planets we will start by looking for single celled life forms too.

    • Photo: Leila Battison

      Leila Battison answered on 19 Mar 2012:

      Humans are made of cells and water and bone and protein and things, and they always have been. But maybe you mean where did humans come from?

      As far as we know, humans and all living things on earth evolved from a kind of bacteria that first got started on earth 4 billion years ago. The bacteria got organised into a thing like an amoeba, and then lots of amoeba’s came together to make a sponge and plants, and then animals got started and then animals with a backbone and then animals on land, and then apes and then humans! It’s an unbroken chain of evolution that has been going on for 4 billion years!

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