Most of our bodies are in a constant cycle of dying and being rebuilt to postpone the inevitable. The gut is perhaps the most fascinating example. As you can imagine it comes in contact with a lot of nasty stuff that damages tissues.
To stay healthy, the cells that line this organ are constantly being renewed. Cells just below the intestine’s surface divide every twelve to sixteen hours, and the whole intestine is refurbished every few days. I figure that by the time an unsuspecting person reaches the age of forty, the entire lining of her large intestine has been replaced several thousand times. Billions of cells have been shuffled each go-round. That makes trillions of cell divisions and whispered messages in the DNA to pass along to the next fellow in the chain. With such numbers, it would be nothing short of a miracle if no copying errors were made, no messages misheard, no foul-ups and instructions gone awry. Perhaps it would be better just to remain sitting and wait for the end. No, thank you.
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