# Is your genetic code fixed at birth?

**URL:** <https://boards.straightdope.com/t/is-your-genetic-code-fixed-at-birth/415378>\
**Category:** Factual Questions\
**Created:** [August 12, 2007, 9:58pm UTC](https://boards.straightdope.com/t/is-your-genetic-code-fixed-at-birth/415378 "2007-08-12T21:58:14Z")\
**Posts on this page:** 1\
**Page:** 2

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**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\
**Post date:** [August 14, 2007, 7:16pm UTC](https://boards.straightdope.com/t/is-your-genetic-code-fixed-at-birth/415378/21 "2007-08-14T19:16:11Z")

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Of some relevance is an Isaac Asimov essay titled _The Enemy Within_, which describes, in summary  
[ul][li]DNA always contains certain elements; carbon, phosphorus, oxygen, etc.[/li][li]Some small but measurable percentage of these elements in nature consists of unstable isotopes[/li][li]Given the number of DNA molecules in a human body, some percentage contain unstable elements[/li][li]Over a human lifetime, there will be a small but steady number of breakdowns where an isotopic atom within a DNA molecule collapses, breaking the molecule and creating a mutation[/li][li]The vast majority of these fragmented mutations are nonviable and quickly removed, but some could be precancerous[/ul][/li]  
Hence, an external agent isn’t necessary to cause mutations/cancer. Each of us is carrying billions of tiny time-bombs and while the vast majority explode unnoticed, some… don’t.

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