[rowyourboat]

> Thus, there is stronger evolutionary pressure to pay the cost of maintaining these systems.

... which implies that it is biologically possible to maintain them, which implies in turn that aging is a biological trade-off and not a physical inevitability.

[atmanthedog]

Yes, I agree. I guess the question is what is meant by inevitable. The meanings of biological and physical in this instance aren't really all that different, if the biological problem is a limitation of the underlying physics. Ultimately, the scarcity of usable energy is driving this trade-off, which is a physical limitation of the universe. It becomes 'possible' in the sense that a O(n^100) algorithm is 'feasible' (see Arora and Barak, section 1.6.2). If maintaining a youthful state indefinitely increases our energy consumption hundredfold entirely due to the cost of maintaining a low entropy state in a highly complex system, is that really 'possible'? If we have to pay an ever increasing energetic cost to maintain ourselves, it is both a biological trade-off and a physical inevitability.

[Arbalest]

I was driving at a similar point, but I think this might be a % of available slack in lifespan, which does not discount physical inevitability.