Life itself exists entirely contrary to the thermodynamic arrow of time. That law essentially states that over time, entropy tends to increase. Life itself, by

Life itself exists entirely contrary to the thermodynamic arrow of time. That law essentially states that over time, entropy tends to increase. Life itself, by definition, is a temporary trend away from increasing entropy. Cells organize and do things within and to their environment to lower entropy. They cannot grow or multiply or evolve except when they are acting in opposition to the thermodynamic arrow of time. But the Law of Thermodynamics won't fail in this process, and eventually the cell's ability to counteract (yet never actually negate) it absolutely does cause every cell to fail eventually. Therefore, aging and dying will be with us forever. At least until we find a way to deny and counteract the effects inherent to thermodynamics. And that would be a whole lot of work since nature is entirely against us on that one. Also, we don't even know what causes life. We can mix all the chemicals and zap it just so, and we have only ever failed to spark new life into existence. Referring to aging as an inefficiency completely ignores the amazing feat that life is in the first place. Aging is the buildup of failures within the anti-thermodynamic efficiency we have evolved so far. Let me know if you're interested in the Wolfram Alpha friendly math behind it. Or the chemical processes that are relevant to it.