Sunday, January 21, 2007
How to Live Forever
Who Wants to Live Forever?
As far as anybody knows, humans are the only animals that have a sense of mortality. For a very long time - presumably ever since we gained this awareness of impending death - we have speculated about the prospect of immortality. Not all cultures wish for immortality. Some religions, perhaps most religions, would regard any search for immortality as undesirable. With the greatest respect to those who do not want immortality or do not agree with it, we must surely admit that many of us - including many of religious faith - would welcome immortality, or at the very least, a prolonged life.
Civilisation Produced Old Age
Before we look at the ways in which this could be achieved, let us consider where we are now. Humans have evolved into the dominant species on earth. Fewer and fewer predators have threatened us as we have gained in strength, cunning and inventiveness. As a society we have learned to harness nature to the extent that food can be stored and packaged and eaten without the need for all of us to hunt and gather. Medicines have been developed to counter disease. We have found ways of keeping our water clean for drinking. Many of us can heat our homes (or even cool them) when necessary, and to a greater or lesser extent look after our old as we look after our young. We have become civilised.
Wear Out
The phenomenon of old age that civilisation has brought to us sets us apart from other animals. It is virtually unheard of to see old age amongst wild animals. As we have become civilised our bodies have not caught up yet. They were never designed to last for centuries because uncivilised man could never have lasted that long in its wild environment. We die because we wear out - not because we can't feed or look after ourselves. The good news is that we are catching up. Each generation (usually) lives longer then the one that went before. Many of us are choosing healthier lifestyles that helps to prolong life. But we are still wearing out.
Body Part Replacement
Scientists and surgeons have become increasingly knowledgeable about transplants of human body parts. The problem of rejection is not the barrier it once was. With the advent of DNA technology it is possible, in theory at least, the "grow" a human body part using the DNA blueprint found in just a small sample. Putting these two facts together, there is a real chance that we will soon have the means to transplant most body parts. In time we could replace all body parts. Once transplantation is perfected we would then have the means to replace worn-out body parts at will. We could all have a scan where a DNA profile of our bodies was compiled. The information in our personal database would be used in order to grow our replacement parts. Using micro-surgery techniques, new parts could be fitted every 5 years! Can you imagine it?
What About the Brain?
Change as many bits as you like, but take the brain away and then surely the person no longer exists. Even if it were possible to grow a replacement brain, how would the information from the old one - including our very state of existence and self-image - be transferred to the new one? Well, the brain is indeed a special case as it holds not only our thoughts and memories but also our sense of being. Because of this, swapping one brain for another and disposing of the old one would be tantamount to murder and defeat the point of the whole exercise. On the other hand, if the brain could not be rejuvenated just like the rest of the body, it will die from old age anyway.
Brains Rarely Fail
There are various ways of dealing with this issue. It must be remembered that thousands of our brain cells are dying every day. It is possible for new cells to be created, but the rate of cell death is far greater than cell creation. Whatever the reason, the rate of aggregate brain cell death seems to grow as we age. That said, it is very common for the brain to remain in a good state whilst the rest of the body fails. When people die of old age, it usually a part of the body - such as the heart - that fails and rarely the brain itself.
Apoptosis
Why do brain cells (or neurons) die? There are various causes. They are certain illnesses, accidents and the use of certain drugs (e.g. alcohol) or other environmental toxins. These factors only play a minor part in brain cell death. A more common cause is apoptosis. This is where cells effectively commit suicide. This process is not fully understood but is thought to be necessary for the long term health of the brain. It is thought that cells that are in some way damaged (for instance their DNA might have become scrambled) die before they can cause damage to the rest of the body. It is also thought, however, that apoptosis occurs to cells virtually at random. One idea is that, as our body fails certain neurons are no longer required and simply expire rather than use resources. This may be a significant theory: our bodies wear out: we slow down: less stimuli reach the brain: the brain doesn't need as many neurons: apoptosis results.
Introducing New Cells
Perhaps apoptosis is the key to the fact that our brains generally outlive the rest of our body. The brain simply gets leaner but stays meaner compared to other body parts that simply cannot shed unwanted or bad cells. So why even think of transplanting the brain? There is no reason to replace parts of the brain because unwanted cells die out voluntarily. One idea is simply to add new cells, prepared with the correct DNA structure. With nano technology it would be possible for microscopic robots to enter the body (perhaps through the gut, if taken regularly as a drug) and carry the new cells with them to the brain. It may be possible for a one-off procedure to deposit a culture in the body that will act as a brain cell reservoir. Nano robots would release new cells at an appropriate rate. In addition, if limbs were being regularly replaced, the body as a whole would be quicker and this would undoubtedly result in a lower rate of apoptosis. Oh, and easy on the alcohol!
In our throw-away society we may have lost the habit of replacing parts. The thing about us humans is that we can't simply be replaced by a new model. We need to be renovated and renewed occasionally. Perhaps a few of the things we buy could get the same treatment. When I am not thinking about immortality, I am promoting Insectocutor Fly Killers. We are always happy to sell you a new model. We also, however, carry a range of spare parts. There are some Insectocutor models out there that are over 30 years old. We are proud to have supplied the odd spare part when it has been needed. Immortality indeed!
As far as anybody knows, humans are the only animals that have a sense of mortality. For a very long time - presumably ever since we gained this awareness of impending death - we have speculated about the prospect of immortality. Not all cultures wish for immortality. Some religions, perhaps most religions, would regard any search for immortality as undesirable. With the greatest respect to those who do not want immortality or do not agree with it, we must surely admit that many of us - including many of religious faith - would welcome immortality, or at the very least, a prolonged life.
Civilisation Produced Old Age
Before we look at the ways in which this could be achieved, let us consider where we are now. Humans have evolved into the dominant species on earth. Fewer and fewer predators have threatened us as we have gained in strength, cunning and inventiveness. As a society we have learned to harness nature to the extent that food can be stored and packaged and eaten without the need for all of us to hunt and gather. Medicines have been developed to counter disease. We have found ways of keeping our water clean for drinking. Many of us can heat our homes (or even cool them) when necessary, and to a greater or lesser extent look after our old as we look after our young. We have become civilised.
Wear Out
The phenomenon of old age that civilisation has brought to us sets us apart from other animals. It is virtually unheard of to see old age amongst wild animals. As we have become civilised our bodies have not caught up yet. They were never designed to last for centuries because uncivilised man could never have lasted that long in its wild environment. We die because we wear out - not because we can't feed or look after ourselves. The good news is that we are catching up. Each generation (usually) lives longer then the one that went before. Many of us are choosing healthier lifestyles that helps to prolong life. But we are still wearing out.
Body Part Replacement
Scientists and surgeons have become increasingly knowledgeable about transplants of human body parts. The problem of rejection is not the barrier it once was. With the advent of DNA technology it is possible, in theory at least, the "grow" a human body part using the DNA blueprint found in just a small sample. Putting these two facts together, there is a real chance that we will soon have the means to transplant most body parts. In time we could replace all body parts. Once transplantation is perfected we would then have the means to replace worn-out body parts at will. We could all have a scan where a DNA profile of our bodies was compiled. The information in our personal database would be used in order to grow our replacement parts. Using micro-surgery techniques, new parts could be fitted every 5 years! Can you imagine it?
What About the Brain?
Change as many bits as you like, but take the brain away and then surely the person no longer exists. Even if it were possible to grow a replacement brain, how would the information from the old one - including our very state of existence and self-image - be transferred to the new one? Well, the brain is indeed a special case as it holds not only our thoughts and memories but also our sense of being. Because of this, swapping one brain for another and disposing of the old one would be tantamount to murder and defeat the point of the whole exercise. On the other hand, if the brain could not be rejuvenated just like the rest of the body, it will die from old age anyway.
Brains Rarely Fail
There are various ways of dealing with this issue. It must be remembered that thousands of our brain cells are dying every day. It is possible for new cells to be created, but the rate of cell death is far greater than cell creation. Whatever the reason, the rate of aggregate brain cell death seems to grow as we age. That said, it is very common for the brain to remain in a good state whilst the rest of the body fails. When people die of old age, it usually a part of the body - such as the heart - that fails and rarely the brain itself.
Apoptosis
Why do brain cells (or neurons) die? There are various causes. They are certain illnesses, accidents and the use of certain drugs (e.g. alcohol) or other environmental toxins. These factors only play a minor part in brain cell death. A more common cause is apoptosis. This is where cells effectively commit suicide. This process is not fully understood but is thought to be necessary for the long term health of the brain. It is thought that cells that are in some way damaged (for instance their DNA might have become scrambled) die before they can cause damage to the rest of the body. It is also thought, however, that apoptosis occurs to cells virtually at random. One idea is that, as our body fails certain neurons are no longer required and simply expire rather than use resources. This may be a significant theory: our bodies wear out: we slow down: less stimuli reach the brain: the brain doesn't need as many neurons: apoptosis results.
Introducing New Cells
Perhaps apoptosis is the key to the fact that our brains generally outlive the rest of our body. The brain simply gets leaner but stays meaner compared to other body parts that simply cannot shed unwanted or bad cells. So why even think of transplanting the brain? There is no reason to replace parts of the brain because unwanted cells die out voluntarily. One idea is simply to add new cells, prepared with the correct DNA structure. With nano technology it would be possible for microscopic robots to enter the body (perhaps through the gut, if taken regularly as a drug) and carry the new cells with them to the brain. It may be possible for a one-off procedure to deposit a culture in the body that will act as a brain cell reservoir. Nano robots would release new cells at an appropriate rate. In addition, if limbs were being regularly replaced, the body as a whole would be quicker and this would undoubtedly result in a lower rate of apoptosis. Oh, and easy on the alcohol!
In our throw-away society we may have lost the habit of replacing parts. The thing about us humans is that we can't simply be replaced by a new model. We need to be renovated and renewed occasionally. Perhaps a few of the things we buy could get the same treatment. When I am not thinking about immortality, I am promoting Insectocutor Fly Killers. We are always happy to sell you a new model. We also, however, carry a range of spare parts. There are some Insectocutor models out there that are over 30 years old. We are proud to have supplied the odd spare part when it has been needed. Immortality indeed!
# posted by Swathi @ 10:22 PM 
