2 September 1998

There has been much improvement in the understanding of nature in the past few decades. The rate at which new information becomes known about the exact mechanisms at work in biology is astounding. There is obviously still more to discover than there is already known. 100 years ago the average life span was probably 40-50 years. Now it is at least 70-75 years, depending on where you live and how much money you have. Within the last 20 years we have begun to completely eradicate from the earth several major diseases. The only one that has been completed is Smallpox. The last case was wiped out about 10-15 years ago now. (I do not structure time very well.) Children are no longer inoculated for this once common killer. The only known samples of the virus are stored in a freezer. There has been some suggestion that we should dispose of this stock since it poses substantial risk if it were to be released into the population since there is no longer a base of immunity. As technology stands now, we could not recreate it if we wiped it out, so it is probably better to keep it, though why we might need it is hard to understand.

We are well under way, I understand, to eliminating German Measles as well. I have heard suggestions of other diseases too, but eliminating those that have vectors outside humans are probably not practical.

We are also beginning to completely map the DNA encoding for humans. Some lower species have been completely mapped. That is, the sequences of the molecules is known - we still don't understand how the encoding works to do much of what it does. We are beginning to understand some of this. but there is a long way to go. If I were just starting a career now I think I would go into biology. It is bound to be great fun unraveling all the strands of such complex reactions.

All of this is just to show that we are right on the threshold of understanding down to the molecular level most of the processes that control what we know as life. Leaving aside for now any questions about whether there is a God that controls it at any level, it is fairly clear to me that a large part of life is a series of complex chemical reactions. (I wanted to say "biochemical", but I figured that made it obviously a tautology.)

If we come to a more or less complete understanding of this process, one of the things we will probably do is prolong the average human life. It is conceivable, of course, that there are limits to how far this process could be carried out. On the other hand, other medical advances have been made that can contribute to this process: Scientists have recently cloned a sheep. They have been able to grow a human ear on a mouse. They are close to developing artificial substitutes for many body parts and organs, including skin, blood, blood vessels, knee, hips and other joints, kidneys, lungs, hearts, etc. Even if these pieces wear out after some time, there will still be ways of replacing the worn out parts. We might therefore be able to last forever. Of course, this raises the question of what happens then.

By looking around nature one concludes that all of life can be divided along two possible axis's: those species that reproduce or not, and those species that live forever or not. All of the living species we know of today fall into one category - they reproduce and they do not live forever. It was instructive to me to ponder why this should be so. Suppose that a being somehow were to exist that did not reproduce. It seems unlikely that it would be a "species", since that implies that there are several beings with very similar characteristics. Sooner or later this being is going to be killed, either by another being that wants to eat it or just by an accident. After a short period, there wouldn't be many such beings about. On the other hand, if a being manages to reproduce itself somehow, then the individual being might not continue to exist, but if enough of them exist then there is a substantial probability that some will survive.

The other division of possible species was on the division of those that live forever and those that do not. There appear to me to be two problems with that. The more obvious problem is that if a being lives forever and continues to reproduce, sooner or later there will be so many of them that they will run out of necessary resources or they will pollute the environment to the point that they can't survive (or both). The less obvious problem is this: if a species only reproduced quickly enough to replace those that died then it might be able to avoid the first problem. However, bisexual reproduction allows for chance combinations of characteristics that will give rise to a population with diverse characteristics. Reproduction that is at a very low level or that is asexual will give rise to a population that is more homogeneous and that is less likely to be able to survive a cataclysmic change in the environment. In the long run, then, the majority of the successful species of the world will all be composed of beings that die eventually and that reproduce, and do so bisexually. Convenient, eh?

So, what must happen if we are going to live forever? We have to stop reproducing. At least we have to stop reproducing beyond what is necessary to replace those people that die accidentally. For the near future, not everyone will have access to the technology required to live forever. If for no other reason, much of the technology will remain very expensive for a long time. For this reason it is unlikely that we will have to make this change all at once throughout the world. If some magic potion is discovered that everyone can buy for a dollar a bottle then we are going to have a serious problem. Cultural and hormonal factors will mean that people will not stop having children right away. It will be a massive intellectual problem for people to resist this urge, and quite frankly, I doubt that most people will be able to make it. I suspect that we will gradually extend our lifetimes and that overpopulation will become a much worse problem before we get it solved. It may take some cataclysmic event such as massive global starvation before people collectively decide that the problem must be solved. Overpopulation makes every problem worse. If there were only a million people on the earth then we could probably each pollute as much as we wanted to. The earth could probably handle it easily.