• Question: How long can people live for and why do we die?

    Asked by eve909 to Ed, Sam, Steve, Vera on 22 Jun 2011.
    • Photo: Ed Morrison

      Ed Morrison answered on 22 Jun 2011:

      I think the record is about 120 years, but the average in the UK is about 80 years.

      Surprisingly, the cells in our bodies are programmed to die when they get to a certain age. This is determined by bits on the end of our chromosomes (the structures in which our DNA is stored) called telomeres. In theory this means it may be possible to extend our lifespan by making sure our telomeres don’t wear out.

      For me, the interesting question is why does natural selection design animals to die since it’s about survival of the fittest. The asnwer is, from the gene’s point of view it is more economical to invest in new organisms rather than keep investing in the same one. It’s a bit like if you have an old car it become more and more expensive to keep repairing it. At some point it saves you money to scrap and and buy a younger one.

      Although there are some jellyfish that seem to be immortal and don’t die of old age, although they might still be eaten by something.

    • Photo: Vera Weisbecker

      Vera Weisbecker answered on 22 Jun 2011:

      Ed is right, all organisms have an internal program that kills them in the end. The strange thing is that some really weird factors seem to be related to how long an animal lives – e.g. large mammals live orders of magnitude longer than small ones, and big-brained mammals seem to live slightly longer too.

      There is a strange mutation in fruit flies that makes them live for many times as long as their program stipulates. People are very excited about this because if this effect can be transferred to humans, they could live for absolute ages!

    • Photo: Steven Daly

      Steven Daly answered on 22 Jun 2011:

      I was reading about those Jellyfish this week, they are really cool. When they have released their eggs they actually kinda go into some kind of reverse ageing and turn into the juvenile form themselves! This would probably not be so great for people.

    • Photo: Sam Tazzyman

      Sam Tazzyman answered on 22 Jun 2011:

      Steve, Ed – that’s incredible! What kind of jellyfish are these?

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