Theoretical biologist Josh Mitteldorf and writer and ecological philosopher Dorian Sagan have teamed up to give us a thorough examination of human aging in Cracking the Aging Code: The New Science of Growing Old—And What It Means for Staying Young. The subtitle is somewhat misleading, though: This is not a book on how to reverse aging or achieve immortality. Rather, the authors show us how various life forms age and offer a reflective look at how aging serves as a biological means of maintaining species survival (read: zero population growth).
“Aging,” Mitteldorf writes, “is built into our bodies. . . . Aging doesn’t just happen, but is regulated and controlled by our genes.” This fact, which evolutionists have a hard time making sense of (why, after all, would the body produce a process of weakening and dying that runs contrary to humans’ more robust genes for growth and sexual reproduction?), is the engine of the book, which is also fueled by the tension between what we now know about genetics and the various postulations about human evolution and longevity.
Mitteldorf and Sagan convincingly defend the positive argument for natural selection. The “death program” in our genes prevents limitless life spans, thus circumventing unsustainable population levels, a teardown of ecological systems and eventual species extinction. But there is a secondary, paradoxical theme upon which the book revolves: Though aging is inevitable (despite all the human genome tinkering now going on in many quarters, such as California’s J. Craig Venter Institute), “clever humans can defeat nature’s death program and gain . . . much longer and healthier lives.”
Though modern medicine and science are gaining ground against the delay of debilitating disease and frailty, we humans, the authors say, must address “the fundamental mortality of our physical bodies: Infinity is not part of physics, let alone biology.”