The precise circumstances surrounding the emergence of man on this planet continue to tantalise and elude us. And in spite of many elegant theoretical models (some too absurd to be entertained and others temptingly attractive), we are still making educated guesses while busily assembling fossilised bones and measuring ancient skull cavities in an endeavour to pin down that point in time when homo sapiens first displayed his distinctive human characteristics.

Parallel with these activities is the bottom line of the conundrum: was he the end product of the slow, gradual pro¬cess proposed by Darwin, or was there a quantum leap result¬ing in his almost overnight appearance?

Some anthropologists believe that the advent of Cro-¬Magnon Man was tremendously significant because not only was he, for some inexplicable reason, a vast improvement on prev¬ious models, we evidently haven't physically changed one jot since he stole the limelight from the Neanderthals some 35,000 years ago.

And don't let us overlook those who will not be budged from the belief that the anthropologists have it all wrong and that the first humans stepped from a spaceship. If they did, and given the sophisticated technology involved in getting them here, one cannot help being intrigued by the fact that, far from being endowed with superior knowledge, they were not spared one moment of the tortuous, agonising process of mental evolution. They even had to re-invent the wheel!

And so it goes on: from those who believe that the answer lies in Genesis 1 to those who support Darwin: from Louis Leakey to Erich von Daniken. Perhaps one day someone will be stricken by a blinding flash of inspiration and all will become clear. However — the joy of knowledge apart — I can't see it doing us much good because whatever his origins, mankind's propensity for procreation is getting entirely out of hand.

When the first European settlers reached North America the continent supported an estimated four million Red Indians ¬but only just; they were obliged to regulate their population growth in line with the available food and other resources. Today, with improved technology and organisation, that same land area supports some 250 million people (with food to spare), thus giving support to the argument that human ingen¬uity will always overcome such obstacles.

Well, let's see where that line of reasoning gets us.

It is estimated that in 10,000 BC the world population was five million. From the time of the Roman Empire to the mid-16th century it grew from 250 million to 600 million. By the mid-19th century it had risen to one billion, and by 1930, two billion. Today it is well over five billion and demographers estimate that by 2000 it will stand at about 6.2 billion.

Countries vary in population growth. Costa Rica, for example, has a population-doubling rate of 19 years while Great Britain (with admirable restraint) holds it at 140 years. Esti¬mates differ but the present rate of growth indicates that there will be an overall world population doubling every 50 years.

The land area of the Earth is about 150 million square kilometres. Divide our population into that figure and you come up with about three hectares for every man, woman and child. This may sound a lot but when you deduct the large chunks of unproductive deserts, uninhabitable mountain ranges, bleak reaches of tundra and the polar caps it becomes considerably less generous.

If the population continues to double every 50 years, the total will reach 12.4 billion by 2050. By 2100 it will have topped 24.8 billion and by 2150, a whopping 49.6 billion. And that 3 hectares will have reduced to 60m x 60m of hotly disputed living space per each soul.

Which, unless you have unlimited faith in technology and infinite confidence in world-wide co-operation, is a hopeless proposition.

Clearly, long before then, and assuming that we do not succumb to the insanity of nuclear warfare or similar, steps will have been taken to correct the situation (although what steps I shudder to think).

But, just for the sheer challenge of the exercise, let us imagine that mankind is seized with lethargy and allows matters to take their natural course. The only alternative to population control lies in the development of technology enabling us to ship people off 'elsewhere'. The good old science-fiction scenario of outer space colonisation.

In which case, unlimited people wouldn't be a problem. But don't be so sure.

Using '6-billion-by-2000' as a starting point, and doubling this figure every 50 years, by the year 3000 we would have the staggering total of a little over 6,000 TRILLION people (6 foll¬owed by 15 noughts).

For the purposes of this exercise, let us propose that the optimum population for a planet of our size (and resources) is 3 billion; we would have enough people to populate two million similar planets.

In his entertaining and extremely logically argued book, 'Extraterrestrial Civilisations', Isaac Asimov concludes there to be 530,000 planets in our galaxy (The Milky Way) capable of supporting life as we know it.

Employing this as a basis, and assuming a similar average figure for all galaxies, we would, by 3000 AD, have enough people to colonise four million galaxies. And if that doubled every 50 years, by 3600 AD we could colonise 16,384 million galaxies.

(With all this in mind, imagine the uproar, confusion and the necessity for a rapid re-think if the Second Coming and its attendant Resurrection additionally and suddenly produced all the people who have ever lived and died).

The last figure I read indicated that that the universe contains an estimated 100,000 million galaxies.

The conclusion is clear: we either initiate an immediate population control programme ... or we start looking for a new universe.

Before it's too late ...

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Vic Lloyd's exercise in extrapolating world population statistics (Investigator No. 50), has some frightening implications if taken at face value and without a modicum of elementary research.

While I'm inclined to think that it was all tongue-in-cheek, let's treat it seriously so as not to add fuel to the fires of doomsday pes¬simism.

Vic quotes no sources for his figures, makes assumptions, and erro¬neously bases his whole argument on an equal per capita distribution of the world's land area.

While the world's total population is increasing, but not at the rate Vic suggests, he may be surprised to learn that according to my sources, the world's average annual population growth is in fact, de¬creasing! — from 1.8% in 1950 to 1.7% in 1990, and is estimated to fall to 1% in 2020.

The principal cause of this fall is the decline in fertility rates (the average number of children born to a woman who completes her childbearing years). In all the major regions of the world this decline is, in many cases, below the replacement level of 2.1.

All the OECD countries, with the sole exception of Turkey (at 2.1) had, in 1988, an annual population growth of 0.7%, this is expected to drop to 0.4% by 2010. All other regions were holding average growth at 2.1 % or less, only the Mid East and North African regions exceeded that figure by 1 %. That figure is also expected to fall to 2.5% by 2010.

The problem as I see it, is not over population, but the unequal distribution of population that has been encouraged by urbanisation. Macao for example — almost 26,000 population density per square kilometre, (100% of total). Australia 2.1 per square kilometre (85% of total).

As for Vic's conclusion, population control programmes have al¬ready been initiated in many countries — China, India and the Philippines to mention some, and family sizes in the developed coun¬tries have grown smaller since the turn of the century.

Hopefully, Investigator's readers will not be panicked by Vic's musings into rushing off to the nearest travel agent for a seat on the next rocket for some cosmic destination unknown!

---

Harry Edwards is, of course, quite right. (Investigator No 51) My essay on world population in Investigator No 50 was something of a 'flight of fancy', a kind of 'what if?' proposition. However, although my figures were based on what I felt to be quite valid premises and accurately computed, I didn't dream that anyone would take them as seriously as Harry evidently did.
    
Nevertheless, I was touched by his gracious efforts to allay the fears of the more sensitive of Investigator's readers by playing down all thought of looming disaster. I can only hope that in the long term he turns out to be right.

I was sorry that he felt my reasoning to be 'reprehensible' (an adjective I normally reserve for the most heinous of crimes) and that he saw my lighthearted essay as an exercise in 'doomsday pessimism'. As a matter of fact, far from driving people panic-¬stricken into the streets, desperately seeking the services of an intergalactic travel agent, when this same essay was first published, in the monthly journal of the Astronomical Society of South Australia, nobody blinked so much as an eyelid. Perhaps people who are accustomed to studying huge cosmic concepts are not easily moved to alarm and despondency.

Even so, please let us not be too hasty in writing off my reasoning as being totally misleading (as Harry obviously would have it). A real danger lurks within the semi-humour of all those trillions. The ramifications posed by the performances of individual countries and the fertility of women are really only side issues; the main concern rests on only two factors: the projected world population in 2000 AD, and the estimated rate of annual increase thereafter.

If 'sources' are vital to the validity of the exercise, the first of these is easy to pin down, it comes from Harry's own reference book, Hutchinson's Book of Vital World Statistics, page 12: "The world's population ... is expected to reach 6.25 billion by the end of the century". In my essay I quoted this at the rounded down, and more conservative figure of 6 billion to be on the safe side.

The second factor can only be a guess — just as all such predictions are. I based my extrapolation on the fact that for years, demographers have used a 'three-decade' period for the doubling of the world's population. Again, in order to present matters in the most favourable light, I stretched this to a 'fifty-year' period.

This latter liberty may be frowned upon by the pedantic but, as an alternative, and judging by Harry's (Hutchinson's) statistics, a one per cent per annum world population increase would probably be the best we could ever hope for unless some very drastic steps were taken. Assuming this to be the case however, each passing year would see the world pool of people growing by at least 60 million. Multiply this by the 50 year bracket envisaged in my essay and even conservatively, you arrive at 9 billion — and by 2100, a total exceeding 14 billion. This, by the way, if you work it out, is far less frightening than Hutchinson's estimated 8.5 billion by 2025.

But does this revision on my original estimate really make a significant difference? Isn't the end result (postponed by only a relatively few years) much the same? If we extrapolate these revised figures don't we still end up in a mind-boggling plight where everyone is desperately short of living space, food, water, fuel, and in some cases breathable air because there are simply too many of them?

I think I made it clear in my original essay that I didn't seriously think that space colonization is a feasible solution. As one devoted to the principles of astronomy I can see too many technical pitfalls in that proposal — quite apart from the horrendous cost involved. Who, in this money-hungry society is going to invest all those necessary billions of dollars to transport only a few million people (a fleabite compared with the total) with no profit forthcoming for centuries — if ever?

Fortunately, again quoting the Guinness Book of Records, "Some demographers maintain that the (population) figure will (or must) stabilize at 10 - 15 billion people, but above 8 billion during the 21st century ... " No expansion, explanation or rationale is offered for this estimate so we are left wondering.

At all events, my thanks to Harry Edwards for his interesting (but perhaps a little anxious) feedback to my essay.

I can only hope that this further offering doesn't give rise to any greater disquiet on the part of those who might otherwise have been mollified by his thoughtful and placatory observations.

Incidentally, apropos my reference to the Second Coming, the Guinness Book of Records quotes the estimated total of all the people who have lived and died in the last 600,000 years as 75,000,000,000. On top of the inevitable population crisis, the Resurrection of that overwhelming multitude doesn't bear even thinking about.