• Question: why is our body asymetric and could it ever have anything to do with your research?

    Asked by char2074 to Ben, Dave, Ed, Sam, Susana on 24 Jun 2013.
    • Photo: David Briggs

      David Briggs answered on 24 Jun 2013:

      We are asymmetric because we have just evolved that way – our heart lies slightly to the left, our liver lies slightly to the right – there is no real reason for it – it is just the way we are.

    • Photo: Susana Teixeira

      Susana Teixeira answered on 24 Jun 2013:

      There are quite a few reasons, I’ll mention a few.

      Our body is a sophisticated machine that needs to always balance energy and the need for extras and spares. Let’s say it was symmetric (like with a mirror in the middle): it would need at least 2 of everything, and organs with just 1 single copy would be in the middle with one half on each side.

      That works well for our 2 kidneys, which can function independently but both are used permanently. But for example our heart needs a precise coordination with our lungs, and exact pressures. If there were two, this would require separate circulatory systems, a very important use of energy, or a lot of coordination. Or one of them would be stopped as spare, but then there would be all that unused muscle sitting there wasting energy. Similar reasons make it so that we have just one pancreas, just one liver, one brain (but even our brain is not symmetric!),… these cannot all squeeze in the middle of our bodies, it would make them less efficient. So they are not, and our body starts to have asymmetries.
      Then there are also other effects linked to our brain, external effects that make us develop some muscles more than others, etc.

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