Aging clearly exists, and is (almost) universal. But the fact that organisms have a certain property is only weak evidence that property was selected for. As I commented here, the other possible explanations are that immortal varieties either never arise in the first place, and so can't be selected; or else are always linked to some tradeoff or disadvantage which is selected against. And both options seem quite plausible and I believe have been demonstrated in specific cases.
The mechanism discussed in the article is (from memory, having read about the linked article once) roughly as follows. A cell accumulates damage over time ('ages'). When it divides, it can split damage between both child cells, making them both somewhat younger. Or it can place most of the damaged organelles in one child cell, producing a young and an old cell. This is a tradeoff that (unsurprisingly) is resolved differently by different cells at different times.
But the fundamental idea is that aging is damage accumulating over time. That's what the quote about "a fundamental and inevitable property of cellular life" refers to. There isn't a gene or behavior 'for' aging, and therefore there isn't an available mutation that doesn't age because it doesn't have that gene, and so evolution can't select it.
Contrary to Lander's view that "evolution has installed many many mechanisms to ensure that organisms die and make room for the next generation".
My comment was about the tell tale signs of motivated cognition by the OP, not about the substance of the topic.
At a recent Reddit AMA, Eric Lander, a professor of biology who played an important part in the Human Genome Project, answered this question:
His response:
This seems to me, at first blush, to exhibit the Evolution of Species Fairy fallacy. Evolution doesn't work to benefit species, populations, or the "next generation". If a mutation arises that increases longevity, and has no other downsides, then animals with that mutation should become more common in the gene pool, because they die less often. I remember reading that the effect would not be very strong, because most animals don't die of old age. But why would there be the opposite effect?
I am loath to attribute a very basic error to a distinguished professor of biology. Is there another explanation? Is the claim that evolution selects for mortality true?
Note: Eric went on to add:
This seems to be blatant rationalization of a preconceived idea that death is good. (I doubt he truly believes that extra progress is worth everybody dying.) So perhaps his first statement is also a form of rationalization. But it seems improbable to me that he would make such a statement about biology if he didn't think it well-founded. More likely there's something I'm misunderstanding.
ETA: one of the first Google results is this page at nature.com, The Evolution of Aging by Daniel Fabian, which goes into some depth on the subject. The bottom line is that it agrees with my expectation that evolution does not select for mortality. Choice quotes:
How could a distinguished professor of biology, a leader of the HGP and advisor to the US President, get something so elementary wrong, when even a biology undergrad dropout like myself notices this seems wrong?
ETA #2: Gwern points to the Wikipedia article on Evolution of Ageing, which lists several competing theories of the evolution of aging (and therefore mortality). This shows the subject is more complex than I had thought and there may be good reason to believe mortality is selected for by evolution (or at least is reliably linked to something else that is selected).
I should be glad that I didn't discover an obvious error being committed by a distinguished professional, even if he may be ultimately wrong!