[extropy-chat] evolution / selection of cells within a single body / lifespan

[Ensel Sharon]

Hello,

I am very interested in learning more about the concept of cells or
mitochondria evolving, or facing selection pressure, within a single body,
and within a single human lifespan.

Nick Lane speaks a little about this in his book _Power, Sex, Suicide_,
but not that much.  I am wondering:

1. If anyone can recommend some other sources/books that talk more about
this idea/theory

2. If there is an accepted term used to describe this, that I obviously
don't know.

Also, any comments/discussion anyone here would like to offer would be
greatly appreciated.