 All right, let us, let us begin here. That implies a social answer to the question, not a biological answer to the question. Yes. I'll begin by asking members of the panel if they have any questions or observations about Dr. Olashansky's talk. That was a wonderful talk, Jay. You're fantastic. And he leaned over to me just a minute ago and said, was my distinction between aging and disease clear? And I felt a little embarrassed for a moment because I said, well, actually not entirely. So I was going to ask him to explain it again. We pursued the conversation a little bit while we were waiting for things to start it. And he said to me, I said, would you focus on Alzheimer's disease? Is that a disease or is that aging? And he said, well, Alzheimer's disease has an ICD code. That means doctors can fill it in and get paid occasionally. And I said, oh, you mean the difference between aging and disease is a social one. So to a biologist, what's the difference between aging and disease? Could you clarify it for me? Okay. Well, first of all, let me emphasize one thing that I didn't point out in this particular talk. I did talk about this a couple of days ago. And that is if we could hypothetically come up with a cure for the three main things that kill us today, which we know is heart disease, cancer, and stroke, those three causes of death would then be replaced by three others. You remember the force of mortality, taking individuals out at those very old ages? The force of mortality would be a relenting force. It would not give up. And so three new causes of death would replace those that would be removed. And incidentally, we would only gain about 10 to 15 years in life expectancy at birth if we could hypothetically eliminate the three main causes of death today, heart disease, cancer, and stroke. And so the question is, what happens if you eliminate all of the main things that we identify that kill us today, which you'd add a few things to heart disease, cancer, and stroke, diabetes. And as I said, Alzheimer's does have an ICD code, an accident, homicide, and suicide. And what's left, and infectious diseases, of course, and what's left behind is senescence, is aging. And my guess is that many of the individuals who would be saved from dying from these major fatal diseases would instead succumb to either multiple organ failure, which is exactly what you see in animal populations, that are protected for a long time, multiple organ failure. Or my guess is you would see infectious diseases reemerge as these individuals, as their immune systems, senesce, or age, and they would succumb to an infectious disease. Did I answer your question? Dr. Selcoe? I wanted to touch on a different point. I found Jay's address most stimulating. And when I speak later on, I'll tip my hat in terms of whether Alzheimer's is a part of the aging process or a disease. I'll say now that I think it's largely a disease. But I was interested in one of the early curves you showed about the decline in birth rate and the decline in mortality at the same time, death curve, and how that huge bulge that we currently experience is narrowing down. And I wonder that besides the many other questions that your address raises about the relationship between disease and aging, that there becomes ironically an increasing imperative to extend the duration of life because the birth rate is falling so dramatically in some developed nations. And what I'm thinking of is that I've always been terribly concerned about population explosion, and I still actually am and worried about that. But I know that in Japan, there are good predictors that the population will decline from 110, 120 million now to 75 million within less than a century. And even in Mexico, the number of live births per woman is declining rapidly. So I wonder whether another reason for thinking of both approaches to extending the duration of life, both solving late life diseases and changing the aging process, if that's possible, is because we will in 300 years from now or 400 years from now run out of folks to manage the remarkable complexity of environment and structures we've created. Who's going to maintain structures? And if it is going to decline, as your curves predict, we're going to have to start cutting back on the number of dams we maintain, the number of electric plants we maintain, et cetera, et cetera. We won't need them number one, but we also wouldn't want to have them age themselves. You know, it's funny you should ask this question. When I came into the field of demography in the late 1970s, I came in principally for this issue of population growth, that difference between the birth rate and the death rate. And we knew, you know, the population bomb had just been published by AeroLik and a number of scientists were talking about the explosive population growth that was going to occur. And I went into the field in part to help to influence this dramatic growth in population size. And it was done principally through reducing, starting by reducing death rates and then the birth rate declined because there weren't so many replacement children. And then there were a number of other technologies that were used to help reduce fertility, and we succeeded. We achieved exactly what we set out to achieve, and that was zero population growth in some places and negative population growth. I was a member of NPG back in the late 70s in an effort to do exactly what you're saying might potentially be dangerous. And the recognition at the time was that we've achieved, I think it was roughly five and a half billion people on the planet at that particular time period, demographers, we knew back then that there was a momentum built into the age structure that ultimately was going to lead to a population of anywhere between 10 and 14 billion people by the middle of this century. And that's in all likelihood still going to happen. Remember, most of the population growth is going to be occurring in the developing world, not the developed world. We are seeing extremely rapid declines in fertility rates. We now have total fertility rates. For those who don't know, a total fertility rate is the total number of babies produced per woman in a lifetime. So the TFR, the total fertility rate throughout most of human history was about seven. About seven babies per woman. It declined very rapidly and replacement is 2.1. We are now seeing TFR's total fertility rates of about one to 1.2 in places such as Italy and elsewhere. And indeed, you're right. There in all likelihood will be this decline in population in the developed world. We probably won't see it in the developing world for some time. And I think it's a good thing. I think it is exactly what we set out to achieve a long time ago. And I'm not concerned that anytime soon we are going to see a small enough population that we have to start worrying about our fertility. I mean, we know we're already at 6.5 billion today. We know that is inevitably going to go up to at least 8 billion, perhaps as high as 10 billion, by the middle of this century, just as a result of momentum. Even if we continue to reduce fertility rates. So I'm not really concerned at all about that particular problem. And let me emphasize one related point. Because this came up when somebody asked me this question earlier about what would happen if we succeeded in achieving immortality today. Because remember, I showed you those birth rates and death rates. What if we became immortal today? Wouldn't that have a dramatic negative effect on population? We see a population explosion far worse than what we saw during the course of the 20th century. And the answer, surprisingly enough, is no. If we became immortal today, if we could somehow give a pill to everyone that would allow them to live forever, the growth rate of the population would then be defined by the birth rate. Whatever the birth rate is. And that's a simple percentage. So with a birth rate of 1%, it takes about 70 years to double. The same mathematics as the money in your savings account. With a 1% growth rate, it takes 70 years for your money, your $1 to turn into $2. It's the same with human population growth. A 1% growth rate leads to a doubling in about 70 years. In the post-World War II era, the doubling time, the growth rate was 4%. And the doubling time was about 18 years. Every 18 years, the population was expected to double. That's why we were so worried. If we became immortal today, the growth rate would be defined by the birth rate. The birth rate is less than 1%. In developed nations. In developed nations. So in the developed world, immortality would lead to growth rates that are a fraction of what they were in the post-World War II era. Surprise. Dr. Hayflake? Well, first let me congratulate you on a brilliant presentation. But I'd much rather hear questions from the audience than questions from the panelists. Okay. All right. Well, here we go. If longevity is key to reproductive capacity, why don't men live longer than women? Okay. Very good question. Actually, this question does indeed come up repeatedly. I'm waiting for one question I haven't heard yet and I hope you're working on it. Let me just say, last year my colleagues and I published an article addressed to this very issue, where we looked at the timing with which reproduction occurs both in males and females in the developed world and the developing world in high fertility populations, in low fertility populations, and ultimately reproductive output of humans. We define reproductive output as the number of babies essentially pushed out during the course of the reproductive period. What we have discovered is that in the case of humans, 75% of all reproductive output is accomplished by the age of 32, whether you're a male, whether you're a female, whether you're in the developed world and the developing world. So the underlying biology of reproductive output in humans is the same whether you're a male or a female. Now, of course, males are capable, some males are capable, at least in theory, of producing offspring much later in life, but it's the underlying biological similarities between males and females and the underlying biology and life and death that leads to the similarity in the timing with which this occurs. Here's another question. Does the innate toxicity of oxygen contribute over time to the inevitability of our death before the age of 120? The paradox is what gives us life for sure is death. Well, I'm going to defer the fundamental answer to that question to those who have far greater expertise on this than I. You know, the biochemists and the biologists, I do not consider myself. You know, Len would be very good at answering that, but I will say that that particular phrase, the very last phrase, was a particularly important one because we have said this in our articles, and that is as soon as the cellular machinery of life switches on, the body sows the seeds of its own destruction. We essentially produce the very chemicals that lead to the accumulated damage that ultimately is what we see as aging or senescence. Okay. I think we have a physicist in the audience here. Is senescence simply accepting or illustrating the second law of thermodynamics, entropy? Len, Dr. Hayfleck is laughing. The short answer is no because biological material like humans are open systems. We throughout our lives have access to food and oxygen and all of the other necessary elements for life, but we still age, consequently being an open system, the second law of thermodynamics doesn't apply. That's good to know. I thought there should be a little good news presented here. Can you comment on the relationship between extended longevity and distinct mitochondrial haplitites in Italian, Asian and Swedish populations? That's not a question for me. Well, the questioner is trying to make a link between extended longevity in certain populations and mitochondrial haplitites in Italian, Asian and Swedish populations. I don't know specifically the answer to that question, but the answer to any question posed along these lines is that we really do not have any fundamental knowledge about the determinants of longevity. And I'll say a great deal about that in my presentation this afternoon, so perhaps we'll postpone a more thorough answer to later. Okay, here's another one. Do you believe that you can predict the age an individual will live to? For example, in the Twin Cities Marathon, there was a 99-year-old who ran a 340 marathon. How long can he expect to live if we can? The short answer is no. It is not currently possible to predict the duration of life of an individual in spite of the fact that there are plenty of people out there telling you that they have a way to do so. It is not currently possible. The answer to this question, by the way, you said he was, what, 99 years old? In the back of my book, I have a table. And in the table in the back of the book is what's called the life table. And in the life table, we list the expected number of days of life remaining based on the number of years that you have currently lived. And in that particular case, I think a 99-year-old on average could be expected to live another, I think it was, it's about two to two and a half years or roughly whatever, about 800 days or so. Let me emphasize, by the way, the reason why I use days to answer questions like this is in order to emphasize that what's really important is the time that we have at the daily level, not at a population level trying to dramatically extend duration of life. I have given talks on this very topic before to groups of individuals, all of whom are over the age of 85. And I do inevitably open up the book and say, on average, men your age are going to live about 2,500 days. And I'll tell that to my father. And this might sound like a depressing conclusion. And in fact, I was delighted to hear that the men in these groups that I've spoken to and my father have also come up to me and said, Jay, you're not telling us anything we don't already know. We know we're not going to live forever. That's the reason why we're here listening today to this discussion of aging. We're here to learn. We're here to enjoy today. We're here to emphasize the day that we are living now because that's what's important. I was very pleasantly surprised to hear that it wasn't construed as a negative message and it should not be considered one. But with one last question here, I think we have an engineer in the audience. If we redesign the need to bend the other way, what would a chair look like? Well, this is a very good question and I will alert you to a story that's going to appear in, I think it's going to be in January or February. It'll be in the news probably. Well, it'll be within the next couple of months where my colleagues and I have worked very hard to redesign other attributes of the morphology of humans. And not only did we redesign the knee, by the way, we actually introduced a tail because one of the main problems was the lower back is really a disaster for upright locomotion. And so if you extend that tailbone all the way down to the ground, you make a number of other changes. And this is a discovery. I'm telling you now it's a discovery channel story on this very topic. You will see something that looks either much more like a kangaroo or a dinosaur. So if you look at all of the changes that we make in morphology and you add in in particular this extension of the tailbone all the way down to the ground, you're not going to need a chair because you'll be able to just lean back on your tailbone. I think we should probably have churned with that. Thank you very much.