[bykovich2]

What is the selective pressure /for/ cancer-predisposing genes? And it's not as if most cancers act as a reproductive filter -- the majority of them emerge well after the onset of reproductive ability, drastically reducing, if not eliminating, their selective effect.

[zamalek]

> What is the selective pressure /for/ cancer-predisposing genes?

Evolution does not and never has selected /for/ things. It is a process of elimination. What this means is that, since the advent of chemotherapy, we have eliminated selection /against/ certain types of cancer.

> the majority of them emerge well after the onset of reproductive ability

Correct, we have never had an impact on that and likely won't for a very long time (we don't know enough about our genome to do so). As-per this study, we have been curing cancer in children (as we absolutely should) with very little knowledge as to how/why they developed cancer so young. Will their children also be at risk for leukemia? What about their millions of descendants? We don't know. If treatments like this work out then we might not have to care.

[bluGill]

Actually evolution may well be selection against cancer in older people. (may is key - we don't know for sure) Enough Young girls of breeding age have a small tendency to breed with old men. This increases our lifespan by ensuring those who have whatever genetics it takes to live older have more children. It is a small effect, but it is something.