• Question: why do we live!!!

    Asked by ryan to Cathal, Ciara, Emma, Michael, Sive on 14 Nov 2013.
    • Photo: Sive Finlay

      Sive Finlay answered on 14 Nov 2013:

      Hi Ryan,
      The ultimate question! From a straightforward point of view we stay alive because we are large complex organisms made of cells which are specialised for different tasks but which work together to create an overall living body. Why or indeed how did life evolve is much trickier.
      There are lots of different theories for how did life evolve and we’re a long way from knowing all of the details. We do know that environmental conditions in the early Earth were very different to today so early forms of life (i.e. self-replicating molecules) formed under very different conditions. There were some famous experiments done in the 1950s my Miller and Urey where they took a mixture of gases which were found in the early Earth’s atmosphere, added water and electricity to simulate lightning and ended up with a “sludge” that contained amino acids which are what makes up proteins. What I find tricky though is trying to imagine how the first self-replicating molecules formed. I get the idea that chemical reactions will occur under certain conditions which produce the molecules that are the foundation of life. But how did we then make the leap to producing molecules which could make new copies of themselves? Obviously once self-replicating molecules existed then they would have an advantage over other random combinations because they could produce more copies of themselves and spread to become more common.
      But once you get past the tricky part of how life first started, the question of why life survives is a bit easier. It’s all thanks to evolution. As soon as you have a system of self-replicating molecules which produce variable offspring that must compete for the necessary resources to survive, natural selection will act to ensure that only the “fittest” (molecules which are best at reproducing in their current environment) will survive to pass on their heritable characteristics to the next generation.

      As for the more philosophical question of what’s the purpose of life I don’t think there is an overall grand scheme. From an evolutionary point of view living organisms exist for the purpose of passing on their genes to the next generation (Richard Dawkin’s famous selfish gene concept). Evolution doesn’t have a purpose or direction so I think that there’s no ” why” do we live, we just do.
      Sive

    • Photo: Michael Nolan

      Michael Nolan answered on 15 Nov 2013:

      Hi Ryan,

      an age old conumdrum and there is more than one way to answer this.

      The first is the religous/philosophical answer – because some deity created the universe and us in it, for whatever reason that we probably cannot understand because the deity is too smart for us. We live horrible lives but as long as we are good we then get our place in the afterlife which is a paradise. Science cannot probe this as it works on the basis of faith and is really immune to investigation.

      Next up is the Richard Dawkins approach which I favour. The laws of physics and evolution worked to create a universe in which a sun formed and a planet formed in its orbit that allowed what we call life to form and evolve. Despite many mishaps along the way, life blossomed and here we are today, a product of some simple physical laws and, likely, a large slice of luck. That is how it is, we are here now, so let us do the best we can in our life and stop waiting for this afterlife.

      Next, is the “so what?” approach – I am here and alive, I dont need to be bothered by these questions.

      I like Sive’s initial answer on this, a true scientist way of approaching the question!

      The question overall is a very human centric question, giving the assumption that we are special and the end-product of evolution, helped maybe by God. In fact, maybe the cockroaches are the top of the evolutionary tree and we are just their playthings while they wait to joint their God in an afterlife.

      You might see another take on this in the Hitchikers Guide to the Galaxy where the relationship between us and mice is re-defined and our reason for living is not what we think….

      M

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