Anthropology - Other

The Prehistoric Human Diaspora in or out of Africa Asia Europe China



Tweet
Paul Wallis's image for:
"The Prehistoric Human Diaspora in or out of Africa Asia Europe China"
Caption: 
Location: 
Image by: 
©  


THE PROBLEM: HUMAN REMAINS FROM HOMO ERECTUS INDICATE THAT THESE EARLY HUMANS WERE ESTABLISHED IN MANY LOCATIONS WORLDWIDE, ABOUT 1.5 TO 1.9 MILLION YEARS AGO. FURTHER GENETIC EVIDENCE HAS ESTABLISHED THAT THERE WAS INTERACTION BETWEEN AFRICAN AND ASIAN POPULATIONS.

THE BASIC OUT OF AFRICA THEORY HOLDS THAT HOMO ERECTUS AND LATER HOMO SAPIENS LEFT AFRICA IN WAVES CROSSING INTO ASIA AND EUROPE. H. ERECTUS SUPPOSEDLY LEFT AFRICA 1.5 MILLION YEARS AGO, AND H.SAPIENS 100,000 YEARS AGO.

It will be obvious that the problem and the theory don't have much in common except referring to the same species and the same planet. Professionals please bear with some glaringly obvious statements while I make this argument.

Matters are not noticeably improved by the fact that H. Erectus seems to have been everywhere he was supposed to be "going", nearly half a million years before he's supposed to have left. Perhaps the theory needs some work.

A further possibility is that the Asians were the ancestors of at least some of the others, including one of the Africans. That raises one or two issues, too. Just to complicate things, apparently "out" of Africa wasn't the general theme of some of the early humans. They went to Algeria and Morocco, probably for no other reason than to annoy anthropologists, but they went there.

I have no desire or intent to denigrate the decades of hard work that went into making these discoveries. Quite the opposite. I think the theories are now a poor testimony for the work.

Inevitably, as more information arises, theories get cluttered. Logic gets stuck on details which may or may not be in the correct context(s). Let's try another approach:

(1) The animal in question is a new-ish form of life, a go-anywhere/eat anything, species.
(2) Going anywhere and eating anything, in the prehistoric environment, was a very dangerous process. Long distances increased risks. New food types, poisonous plants, dangerous animals, the dangers are both plentiful and serious, and mistakes can do terrible things to small groups.
(3) The constraints on the movement of any living thing are food and above all water.
(4) Viable populations, able to move or expand for any length of time, must have conditions in which they can prosper. Population growth indicates that H. Erectus was a very successful breeder. Therefore they must have been able to maintain themselves well, and make their operational ranges effective.
(5) Physical obstacles, like mountain ranges, rivers, oceans, ice, snow, deserts, and other esoterica have to be dealt with efficiently to allow movement of any kind, let alone a global spread of population.
(6) A lot of learning is involved in new environs. Tool users have some advantages, but the process of adaption has to be working properly for the rise of population.

From which it might be argued that our ancestors were neither idiots nor prone to making wrong moves when moving into new areas. This movement, from or to anywhere, doesn't seem to have been inefficient. In fact, it's surprisingly successful, given the extraordinary state of Earth at the time of the move, the mid Ice Age, one of the more freakish periods of the planet's history, and one of the less hospitable in terms of environment across a large part of the world.

Food and water, and the realities of their supply, would have necessarily been the dominant factors in H. Erectus' world. It is an established fact that human groups can do severe damage to their own food supply, particularly when the populations get too big to be supported by hunter/gatherer methods. It's just not good economics. So groups split, or a new generation moves on, or a group displaces others on its territory, or from their own. It's a pretty ruthless process, and it's been happening for a long time.

Add to this the facts that:
(1) New areas were available for exploitation, and that hunters and foragers, being wide ranging, would discover better places to live.
(2) Movement for people on foot is severely restricted by hostile terrain. Mountains and deserts aren't much fun as obstacles. H. Erectus might have been the most mobile human being to date, but at a crawl. He was stuck with the areas he could actually access effectively. Savannah might well have been the easy way, but to get out or in to Africa, particularly in the areas where remains have been discovered, indicates that isn't and wasn't the whole story.

Which leaves the theories short on a few practicalities. It is improbable, to put it mildly, that one species just happened to appear in several locations simultaneously. (See what I meant about glaringly obvious statements?) The sheer distance involved makes it very unlikely that a race of obsessive super-pedestrians covered that range on foot, even on a generational basis. They weren't equipped or in a position to be tourists.

So how did they get around the world so fast, to the extent of being in Africa and Asia simultaneously?

By water.

As noted, the physical restraints of terrain have to be overcome. There's also a pressing need for people who can't carry water to be near it. Most rivers and coasts provide a pretty reliable and respectable food supply, and the protein to promote population growth. Starving people can't breed.

Add the use of rivers and coastlines, and mobility and range is increased dramatically. As a further consideration, navigation is a lot more efficient. You just don't get lost. To this day watercourses are standard navigational usage for survivalists. Coastal communities are a regular occurrence in prehistoric finds. It's a bit hard to lose track of an ocean

Another issue needs to be addressed. To get either into or out of Africa, you have to deal with the Nile. For a foot bound animal, it's a real problem. If I'm right, H. Erectus must have had a good working system for dealing with rivers. He would have needed one. His whole global ecology was networked with big, obstructive, dangerous, rivers that he wouldn't have been able to merely swim across. Some of them are also full of very unambiguous predators that would make that very much an acquired taste.

Given that humans have made it a routine practice to set up shop near rivers, for the whole of recorded history, including pre-agricultural, some credence has to be given to establishment of a working principle of settlement and land use, and that must have come from some practical considerations of the past.

In terms of economics, there's a further very positive characteristic of the use of water. It's better energy usage. You can do a lot more traveling, much more quickly, for a much better return. You can trade sea produce for land. You can find more areas to use. You can explore much more efficiently. In North America, the rivers were turned into highways for a good reason. On foot, the areas were just too big. Territory couldn't be defended, or even used properly, on foot. All you'd get out of killing a moose and dragging it back on foot would be a hernia and some spoiled meat, beyond a certain distance. Game animals don't hang around humans, and the distances are potential killers.

H. Erectus, to coin a phrase, clearly had his kit together. To spread globally, this had to be a truly effective, socially and logistically well organized, species, with trustworthy survival strategies.

I use the word "spread" advisedly. This doesn't look like a "nomadic" process. This looks like expansion. Successful species naturally increase their range. They have to. Food doesn't sit around waiting to be eaten. It's no surprise, either, that human groups were in some contact with each other, probably on either side of their ranges, so that groups had at least nominal capacity to link genetically. That perhaps also means that contact and a bit of back and forth between continents was quite within normal possibilities, erratically or otherwise.

This might, incidentally, explain some of the odd cultural similarities that show up at seemingly impossible removes from each other. Ideas are born travelers, and all they need is someone to exchange them. It's been a theory of mine that refuses to go away (in fact the bloody thing won't shut up, and keeps reminding me of itself) that there was at some point a common human culture, a sort of prehistoric benchmark of social and technological ability, which has been diversified into the myriad we see in history and the present.

To achieve that, linkages must exist, all the way back to the earliest times. Discontinuity isn't an option. Wherever H. Erectus came from, and went, I think he's the one who established the methods for colonizing the planet.

The only further point I must make is that facts are under no obligation to fit theories, but theories about facts are obliged to consider practicalities.




















Tweet
More about this author: Paul Wallis

From Around the Web




ARTICLE SOURCES AND CITATIONS