Brutes or Angels: Human Possibility in the Age of Biotechnology

8. Age Retardation: Chasing Immortality for Better or Worse

8 Age Retardation Chasing Immortality for Better or Worse I argue thee that love is life. And life hath immortality. —Emily Dickinson, “That I Did Always Love” One spring day, decades ago, my two best friends and I slowly walked the five blocks home from our grade school, where in a few weeks we would finish fifth grade. Sixth grade brought uncertainties for our friendship because we would enter junior high school, where there were three sixth-­ grade classes. We might become separated. Mulling over the realities of sixth grade, we promised each other and ourselves that we would live to be one hundred. For us, that was promising immortality so as to leave plenty of time for us to make it through junior high school and beyond, even in separate classes, and then afterwards to come back together, inseparable again. We did remain best friends through high school. But one of us did not live to see twenty, and another returned from Vietnam with shrapnel in his shoulder. Nearly all of us wish to live a long, healthy life. Some may even harbor desires to live forever. Personally, I think it would be interesting to live for five hundred to a thousand years, just to see how certain human endeavors turn out. For instance, I would like to know whether we will communicate with extraterrestrial intelligence, our many environmental crises will be solved, humans will reach other planetary sys­ tems, we will abolish AIDs, the world’s major religions will look the same, and war, terrorism, poverty, and prejudice will disappear. Desires to live an extraordinarily long time seem most realizable when Age Retardation / 207 we are young. Children who are healthy and not traumatized by war, poverty , or famine feel virtual eternity stretching before them. I remember feeling that way. But, now mortality is a reality, and I am grateful for every day of health and life. What would it be like to live indefinitely, view­ing the future like healthy, happy children do? This chapter probes humanity’s endeavors to do just that, particularly its most recent scientific approaches to the project. We set out with these questions in mind: 1. Does death benefit the species? 2. What do the terms aging, life span, life extension, and age retardation mean? 3. How can we lengthen human life span? 4. What makes us age? 5. How can we retard the aging process? 6. How do some scientists believe we can make ourselves immortal? 7. How much life extension is likely in the foreseeable future? 8. What ethical issues accompany moderate increases in human life span? 9. What ethical issues accompany indefinite increases in human life span? Age Retardation: The Biology Natural selection gave us aging and death. Now science may be on the verge of thwarting the aging process, and someday it may even be able to prevent biological death. Our first consideration is to learn why we age and how death is beneficial. Aging, Death, and Evolution Since aging and death are so reluctant to yield to our efforts to abolish them, perhaps there are good, biological reasons for their existence and persistence. As is of­ ten the case for things biological, the reasons are tied to evolution. Natural selection acts upon traits that affect in­ di­ vidu­ als’ proficiency at successfully reproducing. The filter of natural selection can act only on in­ di­ vidu­ als prior to and through their reproductive years. The mixing of genes during sexual reproduction provides the greatest source of genetic variation upon which natural selection acts. Any inherited gene 208 / Chapter 8 combination or variant that helps an in­ di­ vidual survive long enough to reproduce will be selected for and any variant that hinders survival through the reproductive period will be selected against. Natural selection tends to push the onset of diseases and infirmities that hinder reproduction beyond the age of reproductive activity. Consider Alzheimer’s disease as an example. The disease is generally associated with old age, but even early-­ onset Alzheimer’s strikes after the normal peak period for human reproduction, which is in the late teens and early twenties. Successful human reproduction requires intensive parental care for several years after babies are born. Therefore, conditions such as Alzheimer’s disease work against successful reproduction, and natural selection tends to weed out genetic conditions that allow Alzheimer’s to appear before we pass our reproductive prime...