Question: Why do people die?

Kevin O'Dell answered on 27 Jun 2014:

Unfortunately nothing lasts for ever. And what is true about cars, houses and every object, is true about living things.

The biggest problem living things have is that every time a cell divides, it’s chromosomes get a bit shorter. Therefore most cells can only go through 60-100 cell divisions before the shorting of their chromosomes mean that cell will die.

Somehow when we make sperm or eggs this process is reversed so the new embryo has long chromosome ends. Last weekend it was reported that lobsters have found a way to protect the ends of their chromosomes, so in a sense they live forever, though in reality the just don’t age, but will always eventually get eaten.

Dolly the sheep was cloned from an adult cell, and she died quite young for an adult sheep. So researchers argue this is because the cell that she started from (in terms of its chromosome ends) was already a couple of years old. But we can’t conclude anything from the data from one sheep!