Given the chance, would you want to live forever? In the Epic of Gilgamesh, written over 4,000 years ago, a Sumerian king seeks eternal life. And 500 years ago, Spanish explorer Ponce de Leon came to the Americas searching for the fountain of youth. Every generation, a new ploy for outsmarting the reaper emerges–always futile, always in vain. But is the key to immortality within reach? Some people think that technology will help us cure diseases, build new organs, and essentially reprogram our bodies’ faulty software. Futurist Ray Kurzweil calculates that 20 years is all it’ll take for this exponential boom in computing power to help us live forever. But other scientists are more skeptical. They say that to understand immortality, we must understand our own DNA.
Have you heard of the Turritopsis nutricula? It’s a type of jellyfish, said to be biologically immortal. Now, this doesn’t mean that it’s immune to disease or injury, but it is immune to the leading cause of death: aging. That’s because it can revert back to the polyp stage even after it reaches sexual maturity. In essence, it can stay alive forever, since every time it grows up, its cells undergo trans-differentiation to become young and sexually immature again. That’s one way to live forever. So if this special jellyfish can do it, why can’t we?
It’s a complicated question, and scientists think the answers may be deep within the nuclei of our cells, where the building blocks of life are stored. See, every time one cell replicates to become two, its DNA also has to replicate, and when it does that, little bits at the end break off. These areas are called telomeres, and they’re there for that very reason: to buffer against breakage when DNA replicates, so the important bits don’t get lost. But eventually, after enough replication, the telomeres get broken off too. It’s called the Hayflick limit, named for Leonard Hayflick, the first dude to notice that there is finite number of times a cell can divide. But if we can use special enzymes, like telomerase, to increase the life of the telomere, we may also be able to prolong the life of the cell.
If we can get a handle on how to prevent cellular aging, in theory, we can extend life, potentially indefinitely. We may also be able to fight cancer, since the cellular mechanism involved in this deadly disease is closely related to that in aging. In fact, cancer is a type of cell that simply doesn’t die. That’s why it’s so hard to treat. This wouldn’t be a problem, except that cancer cells also divide uncontrollably and invade the healthy cells around them. In fact, biomedical researchers routinely use HeLa cells in their studies. They’re named for Henrietta Lacks, a woman dying of cervical cancer in 1951. Her cells were harvested without her permission, and grown in culture. Since they are so hearty and easily divide; this exact same cell line is used today in labs all around the world and if that doesn’t blow your mind, think about this.
In a way, we’re all already immortal. Think about it: there’s a line of cells, traceable to the earliest human being–in all of us. See, before I became me, with ten fingers and toes, brown hair and eyes, and a funny birthmark on my arm, I was a single cell. That cell eventually divided over and over to make the person you see today. But that single cell was nothing more than a combination of my father’s sperm (with half the chromosomes necessary to make me) and my mother’s egg (also with half of my chromosomes). Together, they made a single cell, and that single cell divided to become all the cells in my entire body, including my own eggs. One day, one of those eggs may combine with sperm to make another human being and so it goes, down the line, until those branches of the family tree end. But if you trace the branches backward, earlier and earlier in time, you’ll find a common ancestor to us all. Really think about it. The cells in your body, in my body, are traceable to the earliest cells of the very first humans and not just figuratively. We are literally made of the same DNA, the same cytoplasm, the same molecular ingredients as those who harnessed the energy of fire, invented tools, developed language, and first stepped out of Africa, the seat of all humanity. They are physically within us. We are made of them and in that way, we are all immortal.
So you tell me. Would you want to live forever? Or do you feel that you already are, being part of the great lineage of humankind, a lineage that will never die?