Now this is interesting. Some scientists at the University of Wisconsin-Madison and Louisiana State University forced the evolution of extreme radiation resistance in e coli bacteria. That alone is unremarkable since it has been done before.
What makes this effort noteworthy is that they were also able to identify the cellular mechanisms involved and that there are active and passive mechanisms of detoxification of oxygen and DNA repair. This could have profound implications for human longevity.
If the above is too dry for you, here is a more "gee whiz" summary: