"life expectancy-)I

One thing we can be certain of is that life expectancy is quite trifling for all kinds of creatures. If a codfish or an oyster produces millions or billions of eggs and only one or two happen to produce young thal are still alive at the end of the first year, then the average life expectancy of all the coddish or oysterish youngsters can be measured in weeks, or possibly even days. I imagine that thousands upon thousands of them live no more than minutes.

Matters are not so extreme among birds and mammals where there is a certain amount of infant care, but I'll bet relatively few of the smaller ones live out a single year.

From the cold-blooded view of species survival, this is quite enough, however. Once a creature has reached sexual maturity, and contributed to the birth of a litter of young which it sees through to puberty or near-puberty, it has done its bit for species survival and can go its way. If it survives and produces additional litters, well and good, but it doesn't have to.

There is, obviously, considerable survival value in reach ing sexual maturity as early as possible, so that there is time to produce the next generation before the first is gone.

Meadow mice reach puberty in three weeks and can bear their first litter six weeks after birth. Even an animal as large as a horse or cow reaches the age of puberty after one year, and the largest whales reach puberty at two.

Some large land animals can afford to be slower about it.

Bears are adolescent only at six and elephants only at ten.

The large carnivores can expect to live a number of years, if only because they have relatively few enemies (al ways excepting man) and need not expect to be anyone's dinner. The largest herbivores, such as elephants and hip popotami, are also safe; while smaller ones such as baboons and water buffaloes achieve a certain safety by traveling in herds.

Early man falls into this category. He lived in small herds and he cared for his young. He had, at the very least, primitive clubs and eventually gained the use of fire. The average man, therefore, could look forward to a number of years of life. Even so, with undernourishment, disease, the hazards of the chase, and the cruelty of man to man, life was short by modern standards. Naturally, there was a limit to how short life could be. If men didn't live long enough, on the average, to replace themselves, the race would die out. However, I should guess that in a primitive society a life expectancy of 18 would be ample for species survival. And I rather suspect that the actual life ex pectancy of man in the Stone Age was not much greater.

As mankind developed agriculture and as he domesti cated animals, he gained a more dependable food supply.

As he learned to dwell within walled cities and to live under a rule of law, he gained oTeater security against hu man enemies from without and within. Naturally, life ex pectancy rose somewhat. In fact, it doubled.

However, throughout ancient and medieval times, I doubt that life expectancy ever reached 40. In medieval

England, the life expectancy is estimated to have been 35, so that if you did reach the age of 40 you were a revered sage. What with early marriage and early childbirth, you were undoubtedly a grandfather, too.

This situation still existed into the twentieth century in some parts of the world. In India, for instance, as of 1950, the life expectancy was about 32; in Egypt, as of 1938, it was 36; in Mexico, as of 1940, it was 38.

The next great step was medical advance, which brought infection and disease under control. Consider the United

States. In 1850, life expectancy for American white males was 38.3 (not too much different from the situation in medieval England or ancient Rome). By 1900, however, after Pasteur and Koch had done their work, it was up to

48.2; then 56.3 in 1920; 60.6 in 1930; 62.8 in 1940; 66.3 in 1950; 67.3 in 1959; and 67.8 in 1961.

All through, females had a bit the better of it (being the tougher sex). In 1850, they averaged two years longer life than males; and by 1961, the edge had risen to nearly seven years. Non-whites in the United States don't do quite as well-not for any inborn reason, I'm sure, but because they generally occupy a position lower on the economic scale. They run some seven years behind whites in life ex pectancy. (And if anyone wonders why Negroes are rest less these days, there's seven years of life apiece that they have coming to them. That might do as a starter.)

Even if we restrict ourselves to whites, the United States does not hold the record in life expectancy. I rather think

Norway and Sweden do. The latest figures I can find (the middle 1950s) give Scandinavian males a life expectancy of 71, and females one of 74.

This change in life expectancy has introduced certain changes in social custom. In past centuries, the old man was a rare phenomenon-an unusual repository of long memories and a sure guide to ancient traditions. Old age was revered, and in some societies where life expectancy is still low and old men still exceptional, old age is still revered.

It might also be feared. Until the nineteenth century there were particular hazards to childbirth, and, few women survived the process very often (puerperal fever and all that). Old women were therefore even rarer than old men, and with their wrinkled cheeks and toothless gums were strange and frightening phenomena. The witch mania of early modern times may have been a last expression of that.

Nowadays, old men and women are very common and the extremes of both good and evil are spared them. Per haps that's just as well.

One might suppose, what with the steady rise in life expectancy in the more advanced portions of the globe, that we need merely hold on another century to find men routinely living a century and a half. Unfortunately, this is not so. Unless there is a remarkable biological break through in geriatrics, we have gone just about as far as we can go in raising, the life expectancy.

I once read an allegory that has haunted me all my adult life. I can't repeat it word for word; I wish I could. But it goes something like this. Death is an archer and life is a bridge. Children begin to cross the bridge gaily, skipping along and growing older, while Death shoots at them. Ms aim is miserable at first, and only an occasional child is transfixed and falls off the bridge into the cloud-enshrouded mists below. But as the crowd moves farther along, Death's aim improves and the numbers thin. Finally, when Death aiins at the aged who totter nearly to the end of the bridge, his aim is perfect and he never misses. And not one man ever gets across the bridge to see what lies on the other side.

This remains true despite all the advances in social struc ture and medical science throughout history. Death's aim has worsened through early and middle life, but those last perfectly aimed arrows are the arrows of old age, and even now they never miss. All we have done to wipe out war, famine, and disease has been to allow more people the chance of experiencing old age. When life expectancy was

35, perhaps one in a hundred reached old age; nowadays nearly half the population reaches it-but it is the same old old age. Death gets us all, and with every scrap of his ancient efficiency.

In short, putting life expectancy to one side, there is a "specific age" which is our most common time of death from inside, without any outside push at all; the age at which we would die even if we avoided accident, escaped disease, and took every care of ourselves.

Three thousand years ago, the psalmist testified as to the specific age of man (Ps. 90:10), saying: "The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labor and sorrow; for it is soon cut -off, and we fly away."

I And so it is today; three millennia of civilization and three centuries of science have not changed it. The com monest time of death by old age lies between 70 and 80.

But that is just the commonest time. We don't all die on our 75th birthday; some of us do better, and it is un doubtedly the hope of each one of us that we ourselves, personally, will be one of those who will do better. So what we have our eye on is not the specific age but the maximum age we can reach.

Every species of multicellular creature has a specific age and a maximum age; and of the species that have been studied to any degree at all, the maximum age would seem to be between 50 and 100 per cent longer than the specific age. Thus, the maximum age for man is considered to be about II S.

There have been reports of older men, to be sure. The most famous is the case of Thomas Parr ("Old Parr"), who was supposed to have been born in 1481 in England and to have died in 1635 at the age of 154. The claim is not believed to be authentic (some think it was a put-up job involving three generations of the Parr family), nor are any other claims of the sort. The Soviet Union reports numerous centenarians in the Caucasus, but all were born in a region and at a time when records were not kept. The old man's age rests only upon his own word, therefore, and ancients are notorious for a tendency to lengthen their years. Indeed, we can make it a rule, almost, that the poorer the recording of vital statistics in a particular region, the older the centenarians claim to be.

In 1948, an English woman named Isabella Shepheard died at the reported age of 115. She was the last survivo 'r, within the British Isles, from the period before the com pulsory registration of births, so one couldn't be certain to the year. Still, she could not have been younger by more than a couple of years. In 1814, a French Canadian named Pieffe Joubert died and he, apparently, had reliable records to show that he was bom in 1701, so that he died at 113. 

Let's accept 115 as man's maximum age, then, and ask whether we have a good reason to complain about this.

How does the figure stack up against maximum ages for other types of living organisms? if we compare plants with animals, there is no question that plants bear off the palm of victory. Not all plants generally, to be sure. To quote the Bible again (Ps. 103:

15-16), "As for man his days are as grass: as a flower of the field, so he flourisheth. For the wind passeth over it, and it is gone; and the place thereof shall know it no more."

This is a spine-tingling simile representing the evanes cence of human life, but what if the psalmist had said that as for man. his days are as the oak tree; or better still, as the giant sequoia? Specimens of the latter are believed to be over three thousand years old, and no maximum age is known for them.