DEPARTMENTS  |
MARCH 2006 – NO. 4 |
|
|
Oral Hygiene
We get old. This inevitability brings to mind wrinkles, osteoporosis, arthritis, Alzheimer's Disease — and maybe a set of false teeth soaking, uncannily, on the bathroom countertop. But that last image is quickly becoming passé. Though fairly common among the elderly just a generation ago, dentures are less prevalent now because of improved oral hygiene and increased public health awareness. Thanks to advancements in dentistry, our 32 adult teeth can last a lifetime.
Not so for elephants, whose teeth determine their life span. An elephant may live into old age, sometimes up to 70 years, only to die of malnutrition when its teeth wear down. Over the course of a full lifetime, elephants employ six sets of molars with only one set fully in use at a time. When the functional set of molars begins to wear down and break off from the burdens of constant grinding, another set of molars erupts behind it, pushing the older teeth forward to the front of the jaw in a horizontal progression likened to a conveyor belt.
As its sixth set of molars becomes brittle and flakes off, the aging elephant must seek out softer, more nutritious greenery than its usual diet of mostly tough grass. The aging elephant bull, which lives a substantially more solitary life than its female counterpart, permanently detaches from its family and spends its last years in isolation, searching for the softer, more specialized food it needs to survive. Elephant cows, which spend their lives in tight-knit family circles, stay with their herds to the end — an end that comes when she can no longer eat at all and, eventually, dies of malnutrition.
If, then, an elephant has survived ivory hunters and the occasional outbreak of disease, if it has made it to majestic seniority with neither manmade nor natural premature punctuation, if it has had a satisfactory life chewing greenery, up-trunking water, and reproducing, then it can look forward to losing the ability to eat. For elephants, to die of old age means to die of starvation, toothless and, in the case of male elephants, alone.
What an awful way to go, you might think. After supporting and repopulating a community and surviving everything that's been thrown at you, you're expected to just wander off and go hungry? For an animal used to eating at least 16 hours a day in order to take in enough greenery to maintain its weight, losing the ability to perform such an important, familiar task — eating — must be in some sense worse than dying. Yet, in the same way that the nine-month pregnancy period prepares women for motherhood, in the same way that the aging process — wrinkles, sensory loss, decline in motor control — prepares humans for death, perhaps the gradual loss of their ability to chew prepares elephants for death.
So what happens when we fiddle with the rules of life? What happens when we attempt to expand the human lifespan through anti-aging and aging-prevention practices? However cruel death by natural starvation sounds, it's an efficient, closed system for controlling mortality rates. For a genus as threatened as the elephant family, it's good news that the elderly members of its various populations will die off, ideally leaving enough food for healthy, younger members on the road to reproduction, who need an average of 300 pounds of vegetation per day.
Humans don't have a closed system for controlling mortality rates. Our population is constantly growing. Even so, gerontologists are hard at work trying to control, prevent, and reverse human aging. There are some who believe that old age is a disease that can be cured. In the U.S., life expectancy was at 77 years at the close of the 20th century, and it is soon expected to reach 90 years as medical advancements in the near future help prevent blood clotting and stroke. Our numbers keep growing, and our lives keep lengthening. Meanwhile, we are running out of physical space and the resources we need to survive.
Is it selfish for our elderly to cling to their last years, hogging economic and environmental resources that perhaps should be reserved for new generations? Or is the mere suggestion just another manifestation of ageism in our society? We have proven that we can beat, or at least delay the effects of, the aging process. But why are we trying? Why is the preservation of the individual human life so all-important when mortality is what defines life? In attempting to revise and extend the natural rhythms of human life, are we throwing the melody, and the global eco-song that envelops it, out of tune? We may be, but are we prepared to accept nature's cycle or face an alternative, gumming our last meal apart from the community of our youth?
