Dateline 2010: the world-historical situation

In the twilight century of western civilisation, the US, the last resting place of western power, has as its primary purpose the containment of rising China. China has as its primary purpose to put the world 'back to rights'. It is playing a waiting game, and is anxious not to jump the gun.

Dark Age Watch (DAW on hold.)

Issue du jour 1: War with Iran--important to containing China but delayed over two years

Issue du jour 2: The world economy--unbalanced, interwoven, delusional--some predict its unravelling

Issue du jour 3: Somalia--leading the world into a dark age

Issue du jour 4: Pirates exploit the decline of international order

Friday, 28 December 2007

To all corners of the earth

Long before Europeans developed an ocean-going capability, humans had reached the furthest corners of the earth. This included not only every continent but even the remote Easter Island, thousands of miles from habitation in every direction. Some other Pacific islands, such as Christmas Island, showed signs of human settlements that had died out before Europeans first arrived.

This tells us something about people. Humanity, like nature, abhors a vacuum. Humans do not naturally stick together and congregate in large numbers. There is rather a continual outward pressure as people try to get away from each other.

The stone age lifestyle, based on hunting and gathering, requires a large amount of land area per person. If human numbers were going to grow, people had the choice of staying where they were and developing more advanced food production technologies (to support more people from the same land area) or move steadily out into virgin territory. In reality, people did not make a conscious choice. Moving to new territory would have seemed like the only option, and it was only when the world had filled up that humans had to confront and solve the problem of feeding more people from the same area of land.

The hunting-gathering lifestyle naturally draws people on. Rather than moving a little each day, hunter-gatherers tend to stay in one place for a while and then relocate in one big jump. It has been said they eat their way out of camp. The longer they stay, the further they have to travel to find new food sources. In a matter of weeks, the daily round trip exceeds twenty or thirty miles, and it becomes necessary to make a major move.

This outward pressure can take people a long way in a short time. It often seems to be assumed that for early humans to migrate, say, a thousand miles would have taken many generations. Yet even in the stone age, people could in principle have travelled from one end of the earth to the other in their own lifetimes. Consider that the circumference of the earth is roughly 25,000 miles. For a stone age person with an active life of 25 years, it would be necessary to travel 1000 miles per year, or under 3 miles per day, to cover this distance. People who follow stone-age lifestyles today can easily do that kind of mileage.

Of course, humans would not have gone directly around the equator, with several oceans in the way. Nor would they have walked directly across the continents, where the way can be barred by mountains and deserts.

Their easiest route would have been along the coastline. Since people reached Australia very early, they may have had simple boats from the very beginning, as they came out of Africa. This would have sped them on their way.

At the beginning of the upper paleolithic, 40,000 years ago, sea level was lower than it is today. This left a continuous land route from Africa to the Americas, with no ice barriers. Here is a map of the world at that time:

The above image was created using a program at the site of Sebastien Merkel. This allows you to enter a given sea level and view the resulting map. Information about how sea level has changed over time is available at this site.

With sea level as above, travel to Australia still required crossing open water. However, this could be done by island-hopping, with each island visible from the previous one. Only the final crossing, of about 100 miles, required a leap into the unknown, but Australia was a large target and people could have spotted it during short sea trips to and from their home base. (Humans could also have arrived at Australia via New Guinea, which was then connected to Australia by land. However, it is believed they did not take that route and New Guinea was settled after Australia.)

I do not accept that humans only gradually diffused through the world. I believe that, following initial speciation in Africa, humans exploded across the planet, so that the world was occupied almost simultaneously at around 40,000 years ago.

We can estimate how long it would have taken people to spread to fill every continent.

Modern hunter-gatherers live at densities of around 1 person per 15 square miles (compared with 67,000 persons per square mile in Manhattan). However, they tend to occupy marginal environments, the best land having been taken over long ago by agriculturalists. Average population densities in the old stone age might have been higher, perhaps as high as 1 person per square mile. Since the habitable area of the world is about 15 million square miles, the total human population of the world, with paleolithic technology, would have been somewhere between 1 million and 15 million.

Let us define the following:

A =total area of the world habitable by hunting and gathering (say, 15 million square miles)
ρ =population density of hunter-gatherers (say, 1 person per square mile)
T =
time for an unconstrained human population to double in numbers (say, 10 years, which was observed on Pitcairn Island during the first thirty years after it was settled by the Bounty mutineers)
t =time

The number of hunter-gatherers that would saturate the world is A ρ, while, starting from a population of 1 (a pregnant woman), the number of humans after time, t, would be 2t/T.

The time taken to populate the world is therefore given by

A ρ = 2t/T


t = T log2(A ρ)

Putting in the numbers suggested above, this comes to about 240 years, for humans to cover the planet.

Of course, this figure should not be taken literally. It is just to give us a feel for the issue. A larger starting population (1 pregnant woman is a little unrealistic) would reduce the time, as would a lower population density, while a longer doubling time would increase it. The point is that humanity's spread through the world does not need to have taken a hugely long time, and in fact it is unlikely that it took a hugely long time.

Note that, once the world was fully populated, population growth would have had to stop until technological improvements allowed more people to be supported from the same land surface. Modern hunter-gatherers are adept at keeping their numbers in tune with their environment, or in fact in tune with what the environment can support in its leanest years. There would therefore have been a short population explosion, followed by near-stagnation (until the development of farming).

Three factors would have slowed down human expansion relative to this simple picture:

  1. Obstructions, such as deserts, mountains and waterways. Crossing the Amazon at its mouth, for example, is like crossing the English channel.
  2. Varying ecological conditions. People who knew how to exploit the flora and fauna of one environment (grassland, forest, seashore) would have had to learn new skills to survive in a different one.
  3. Presence of other hominids. Neanderthals and other hominids already occupied the lands outside Africa. Modern humans would have been competing with them for resources, and might for some time have been kept out of their territories by fear or force.

Nevertheless, people could still have reached every continent in a short time, even if actually filling the continents was slower than the simple argument suggests. Having boats and following the coastline, humans would have remained within a familiar environment while being able to bypass obstacles. As for conflict with other hominids, it might even have been a factor drawing the more capable humans onwards.

Saturday, 22 December 2007

The problem of the Australians

The (aboriginal) Australians worry me.

These folks settled their continent 40 thousand years ago -- or, as many scholars now believe, 65 thousand years ago.

Yet in all that time, they failed to develop beyond the old stone age. They developed no agriculture, metal, or permanent settlements. They scarcely even had clothing.

If Australia had not been discovered from outside, there is every reason to suppose its inhabitants might have remained at the stone age level for ever more -- or until the sun burned itself out.

It is frightening to think that a branch of the human species could have continued in this way forever, never realising its potential, and never knowing anything of the science and technology we have developed.

If the Australians had been typical of humanity as a whole, the human story would have looked something like this...

We can attempt to explain the Australians' lack of development in terms of dark age theory.
Scale (a measure of interactivity) is a critical determinant of a society's institutional and technological complexity. Low-scale societies are inevitably simple, as small groups of isolated people cannot support elaborate economies and political systems. Stuck at the end of the world's main landmass, and separated from it by a lengthy sea-crossing, Australia experienced low scale. It was exposed to few influences. The effective size of the population within reach, i.e. the scale, was too low to sustain development beyond paleolithic levels.

We can refine this argument. For an isolated region, scale depends on the population contained within that region. But the population that exists within the region depends on the technological level (because sophisticated food-production techniques support more people on the same amount of land). And the technological level depends on the scale. What appears to have happened in Australia is that humans achieved an equilibrium, or eigenmode, where technology supported a population that generated enough scale to support that level of technology...and no more. This eigenmode, i.e. self-consistent solution to the problems of social existence, was quite stable and there was no reason why the Australians should ever have broken out of it.

This argument suggests several points of concern:

  1. New Guinea is also small and isolated, yet its inhabitants achieved the neolithic level, unlike the Australians. New Guinea was actually joined to Australia, as the continent of Sahul, until about ten thousand years ago, so why did the Australians not achieve the sophistication of New Guinea? The Polynesian islands are even smaller and even more isolated, yet many had chiefdoms, surpassing New Guinea in sophistication, let alone Australia. We might be able to explain this in terms of humans bringing the relevant technologies and institutions to these islands, so that they were already in a more complex eigenmode. But why were people not able to carry this eigenmode to Australia?
  2. If Australia was too small to support developmental growth like that of the Afro-Eurasian and American world islands, it suggests that, had the world's landmass been more broken up than it is, then humans would not have been able to develop anywhere. The fact that humans have developed must then be seen, in part, as a geographical accident, not an inevitable result of human talents.
  3. Australia is a big place. If we are saying Australia was too small, then just how big does a continent have to be before humans are able to develop beyond the paleolithic? It is true that Australia has large areas of desert, but the Nile Valley is surrounded by desert. And climatic conditions in Australia have changed a lot over the millennia. Why could civilisation not have developed along the valleys of Australia's Orange or Murray-Darling rivers? If we are saying environmental conditions here were never quite right, then just how flukey was the development of civilisation elsewhere?
  4. If Australia reached equilibrium at a technological level commensurate with its size, then could this be the fate of the world as a whole? Will we stagnate at a (much higher) technological level where the planet is able to support just enough population to sustain that level of technology? Could the human race flat-line until the sun goes supernova or something else wipes us out?

The point of these questions is not to deny that Australia's lack of development can be related to its situation, but to show some of the complicating issues that a full theory must take into account and be able to explain.

We should also note two other points:

  1. There is no reason to think, as some might, that the aboriginal Australians lacked the mental capacity of humans elsewhere. All humans today are members of a single species, descended from common ancestors living at most 100-200,000 years ago. On an individual level, aboriginal Australians operate perfectly competently in technologically advanced society; high achieving aborigines include academics, politicians and writers. Australian traditional culture is also sophisticated in its own way; languages and kinship systems are more complex than those of 'advanced' societies; art and mythology are well developed; the boomerang is a clever device; aborigines found honey by gluing feathers to bees, slowing them down so they could be followed. [As far as dark age theory is concerned, the sameness of humans everywhere and at all times is axiomatic. Only when it has proved impossible to build an adequate theory of history on that assumption will the axiom need to be abandoned - we are nowhere near that yet.]
  2. Australians seem to have taken up agriculture at various points, then abandoned it again. Therefore, the situation is not as simple as achievement of an everlasting equilibrium. Stagnation was not total, and perhaps changing climatic conditions sometimes elevated scale sufficiently to promote development in some areas.

Finally, there is the argument of Jared Diamond, in Guns, germs and steel, which is that the move to neolithic (farming) lifestyles depended on the availability of crop plants and domesticable animals. While Eurasia had barley/wheat/rice on the one hand and sheep/cattle/horses/pigs on the other, suitable equivalents in the rest of the world were lacking.

Diamond's argument comes back to the issue of continental size. There is a well-known relationship between the size of an island/landmass and its biodiversity. Hence, the largest continent, with the greatest biodiversity, inevitably had the most suitable species for agriculture. The second largest continent was a runner up, while the smallest continent had too litte variety to provide species with the right characteristics for human exploitation.

This argument is not endorsed by dark age theory, which starts from the assumption that history is a sociological phenomenon, not dictated by random background features such as climatic conditions or availability of domesticable species. In dark age theory, necessity is the mother of invention, so that people would be expected to have found ways of supporting complex society if conditions were right for it. Diamond says attempts to use the zebra as a beast of burden have failed, which he suggests helps explain Africa's lack of development. However, over thousands of years the zebra might have been domesticated as the horse was, had people really needed such an animal. Dark age theory looks for explanations in terms of the inherent logic of human affairs, not in terms of chance, external factors. (This viewpoint may be wrong, but we start from it as an assumption, to be abandoned only when it has demonstrably failed.)

Sunday, 9 December 2007

Human speciation

I want to discuss why my view of the early migrations of the human species differs from the broad academic consensus.

Firstly, to work out when and how humans came to be distributed through the world, we rely on archaeology and, more recently, genetics. Neither perspective is without its problems.

  • Archaeology depends on sites. The discovery of new sites may change the picture. Archaeologists are biased towards a constantly changing picture. Careers are made by saying something new and interesting, not by confirming what has long been common knowledge.
  • Genetic dating depends on mutation rates. These are estimated and, since mutations are random and do not occur at fixed intervals, there is an inevitable margin of error. Furthermore, external factors could have an unknown, systematic effect on the mutation rate. If, for instance, the earth's magnetic field weakened, it would allow more cosmic radiation to reach the surface, possibly elevating the mutation rate.

Archaeologists' and geneticists' models of migration history are evidence-based. This sounds good -- surely our models must be based on evidence -- but means they are subject to caprices of evidence discovery, and uncertainties and revisions of evidence interpretation.

My model is theory-based. Rather than considering only direct evidence for the issue in question, it reflects a broader theory of how human societies operate, based on theories and evidence from a wide range of cultures and historical periods. The point is to build a coherent explanation of the whole of history from a few principles. Incompatibility with specific facts or interpretations, which are subject to the vagaries of academic fashion, does not make or break the theory.

This approach is by no means unscientific. The model makes predictions to be tested against reality. It could be wrong. If it continues to disagree with facts that become increasingly well established, it must either change to accommodate the facts or be abandoned altogether.

I say all this because I choose to start my account of history with a big bang -- the sudden appearance of 'true' human beings in Africa 40 kya (kya = 'thousand years ago'), and their near-instantaneous spread to Europe, Asia, Australia and America. I associate this big bang with a newly evolved ability to manipulate symbols, which I believe underlay art, speculative thinking and 'true' language. In the archaeological record, it corresponds to the transition to the Upper Paleolithic, marked by a new sophistication and variety of stone tools.

My view is by no means original -- the association of a biological event, language skills and the beginnings of human ingenuity was the mainstream view until not long ago. However, it disagrees with some major points of the current academic consensus, which are:

  1. Modern humans appeared in Africa as much as 190 kya. (Nevertheless, it was long believed, and still is in some quarters, that the emergence of the human species was linked to the appearance of the Upper Paleolithic, which is dated to 40 kya)
  2. Australia was settled 65 kya. (This was believed to be 40 kya until the 1980s.)
  3. America was settled about 12 kya. (Increasing numbers of archaeologists think this date should be pushed back at least a few thousand years, with some arguing for dates as early as 40 kya.)

The reason I do not like to believe the human species is as old as 190 ky is that it makes the acceleration of recent times look even more extreme. If it took 150 thousand years to make the step to the Upper Paleolithic, but a hundred years to develop electricity, computing and space flight, it seems we really are in the grip of a runaway process and it can be at most a few thousand years before we conquer the entire universe -- something I find hard to accept.

Such an early date for human origins -- and the implied slowness to move outside Africa and colonise the rest of the world -- also makes humans look much less adventurous than I believe we are.

My prejudices therefore lead me to identify human speciation with the beginning of the Upper Paleolithic -- the point from which growth of mastery over this planet seems to have been almost continuous.

This belief in a link between new technology and a new species can nevertheless be very reasonably criticised. Oppenheimer points out that there is a vast technological gulf between industrial societies and, say, the tribal societies of highland New Guinea, yet both are composed of fully modern humans. There is no compelling reason why the technological revolution of the Upper Paleolithic should have been associated with a step forward in biological evolution.

So I cannot really justify my choice of starting point. All I can say is, let us run with it and see where it gets us.