“That is ridiculous.” I am probably quoting thousands of people who have even considered the possibility that immortals could exist.
Certainly, with the advancements of medical technology, the idea of extended like has occured to many. Our average life span if close to 75 years, versus 40, and that is over the span of only a hundred years. Medical technology is outstanding, and in another hundred years the average life span could potentially be 120.
But I am not referring to someone who is not simply old for a very long time, kept alive by artificial lungs, heart, and dialysis. I am speaking of a true immortal, one who does not age. One who reaches maturity and stays there for an indefinite amount of time.
Yes, popular shows such as ‘Heroes’ or ‘Highlander’ has turned this kind of discussion into a joke, merely pop-culture, and not logical. But I offer a scientific discussion for the possibility.
What is cancer? Cancer is unregulated, uncontrolled cellular division. It also has some special abilities:
1) Cancer cells are not inhibited by the presence of other cells. Typically cells would grow, if done in vivo (this means outside of the body) in what is called a monolayer. Cancer cells will grow on top of one another, forming a mass (tumour).
2) Normal cells have a density limit, at which time they will stop dividing. Cancer cells also avoid this problem.
3) They can spread (metastasis).
Now, cancer cells are also known as ‘immortal cells’, because they have infinite replicative capacity. They can survive forever.
Consider this possibility: What if a mutation in the human body occured which gave cells the infinite replicative capacity, but they remained under the control of the cell checkpoints? Cell checkpoints are what ensures that cells do not divide uncontrollably, and therefore can not form a tumour and spread. The body can actually trigger the programmed death of a specific cell, termed apoptosis, thereby preventing cells from becoming cancerous (this cell death would be activated if a cell has some signs of becoming cancerous).
If a cell could gain immortality, yet remain under the control of cell cycle checkpoints, technically it would behave normally yet divide forever. If this mutation was germline associated, it would be present in all cells. This could give rise to an immortal.
The only risks would be, of course, disease, and possibly the development of a true, malignant cancer in the future.
I hope I have triggered some thought on the subject that has become so ridiculous over the years.