Question: Why do atoms have such long lives, but organisms die?
Tyler Volk: Yeah, well atoms have such long lives because they are made of fundamental particles that themselves are long-lived to infinity. There are some issues about the proton having some kind of a long decay constant, but organisms are dynamical systems made of parts, enzymes that interact very volatility, they have to be rebuilt constantly, the organisms themselves have to have constant inputs of matter and energy in order to carry on to regenerate these complex internal dynamics that they have going all the time.
Question: On the molecular level, what causes humans to die?
Tyler Volk: The body wears down after a while. There are repair mechanisms that we have. You cut your skin; you’ll notice that your skin repairs. You break a bone; the bone repairs. Many of these repair mechanisms, as any of us who are aging know, become less efficient as we get older. And one reason that diseases become more statistically probable as we get older has to do with a general running out of these repair mechanisms; the efficiency of these repair mechanisms that were with us from our birth as human beings, but have themselves a kind of longevity that varies from individual to individual. But you can see, most people when they get to be around 70, 80, or 90, they’re going to look old. There are some certain expectations. So there is some commonality we have as humans as a species in terms of shared genetic capabilities of repair our bodies that wear down over time.