Kevin points out that perhaps I am giving chemotherapy short shrift and not looking at the bigger picture.  I would counter that you can’t really make the latency analogy with human life because we are all born terminal.  “Mean survival time” is a squirrely measure at best because how do you know if someone died (a) because of the cancer, (b) because of the chemo, or (c) because of some other factor (in which the cancer or chemo or both) could be confounding?

If you buy the somatic evolution (SE) argument then there are all sorts of consequences which contraindicate chemo in most cases. …

When I posted part 1, I didn’t realize that Scientific American would be coming out with an entire special issue devoted to cancer in the same month, including an article by Carl Zimmer entitled “Evolved for Cancer?“.

I had hoped that the article would be about the somatic evolution of cancer, and while it touches on this aspect briefly and tangentially, it mostly talks about the evolution of defenses against cancer within the human population as a whole.  There is a critical distinction here: somatic evolution occurs on the cells within a single body in the course of a single human lifetime,* while human evolution happens in a population of many humans over millions of years.**…