Saturday, 20 June 2009

Human Evolution on Trial - Technology - by Terry Toohill

Human Evolution on Trial - Technology

Stone Age cultures are classified, oddly enough, by the different ways they worked stone and the kinds of tools they made from it. More recent human cultures are classified by the style of their pottery. Both these artifacts are very hard and remain pretty much where they were left. In 10,000 years time our present cultures will probably be classified by styles of plastic items. James Burke (1978) pointed out more than 20 years ago it was possible to “tell at a glance the various changes in style of radios over the past forty years”. His book “Connections” is an account of technology’s development in more recent times. Ancient patterns of change provide evidence in support of the wave theory of evolution.

The sequence of the development of ancient stone tool cultures was worked out many years ago, by looking at which types overly others, the upper ones presumed to be more recent. Dating by the radioactive decay of several elements has enabled some absolute dates to be applied to various technologies but the sequence worked out years ago has not usually been altered. Pottery is a relatively recent development in human existence and the defence will touch on its dating in “The Last Point” [Pottery].

Here is a closer look at a short history of the earth (“Time”) without the adjustments of the earlier chart. It shows the names of Stone Age technologies and the human species usually associated with them. The jury will be able to refer back to it from time to time.

Lower Palaeolithic

The earliest human stone technology, at the bottom right of the column, is called the “Oldowan”. This appears about two and a half million years ago and in many regions lasts about a million years, but in other places lasts till more recently. The Oldowan is named after Olduvai Gorge in Kenya where it was first identified. (see also) It has also been found near the Caucasus Mountains (“The First Point” [Caucasus population]). The Oldowan consists of simple, sharp stone flakes and flaked pebbles difficult to classify into types. An example of an Oldowan stone tool is shown in the upper left of map 12 (Roe 1971). The stone tool in the upper right is from China and the one beneath it is from Java. The Homo erectus skull at bottom right is from Johanson and Edey (1982). We’ll return to the lines and arrows soon. Members of the jury will be able to follow the main developments in stone technology by simply following the maps.

About one and a half million years ago throughout much of the world the Oldowan gave way to the more sophisticated “Acheulean” (named from Saint Acheul in France). This is distinguished by bifacial flaking (flaking on both sides of the stone tool). Hand-axes (shown along the bottom and left of map 12) are the most characteristic tool from this period but the tools were still largely undifferentiated into functional types and the technology changed very little over a long time.

As you saw in the chart the Oldowan and Acheulean stone industries are usually referred to collectively as the “Lower Palaeolithic” (palaeo – old). Individually they are sometimes associated with different stages in human development but technological and biological change are not necessarily closely correlated, i.e. technological change does not necessarily indicate a genetic change, or change in species. The Oldowan is associated with Homo habilis and the Acheulean with Homo erectus. But the change in species is usually dated at 1.7 million years ago and the change of technology is dated at about 1.4 million years. Also the hand-axe didn’t make it to Eastern Asia even though Homo erectus did.

Hallum Movius recognised the technological division between east and west at least 50 years ago and the boundary between the two is often referred to as the Movius line (Tattersall and Schwartz 2000). It is the dark line on the map. The defence will show that this line can provide a great deal of evidence about our evolution. It is not just relevant in separating hand-axes from more “primitive” tools. Perthaps the Ganges / Brahmaputra River delta was virtually impassable through much of ancient history.

The continued use of Oldowan technology in eastern Asia and parts of northern Europe has two or three possible explanations. The most likely is that the Acheulean hand-axe developed after the first Homo erectus had expanded around the world. Therefore it would be a very early example of the spread of a technology which failed to reach the marginal areas. Alternatively people may have moved out of Africa with the hand-axe but lost the technology during their migration. The expansion may have spent several generations passing through an area with no suitable stone for example. The series of crosshatched lines in map 12 mark the region where the defence suggests the hand-axe failed to keep up with Homo erectus, for whatever reason. The arrows indicate a possible migration route. Some splitters, who like to see lots of species between Homo habilis and Homo sapiens, offer a third explanation: two species of Homo erectus each with different technologies. In this case the Movius line represents the boundary between the two species.

Middle Palaeolithic

The next stage in the diagram, the “Middle Palaeolithic”, follows on from the Lower Paleolithic and leads to the appearance of the “Mousterian” in Europe and the Middle East (after Le Moustier in France). The possibly related “Aterian” (pdf) (Bir-el-Ater, Tunisia) appeared in northern Africa. Hand-axes become less important, but the Mousterian is generally more advanced than the Acheulean. It results from the development of a technique known as “Levallois” (pdf) (a suburb of Paris). It shows a leap in mental ability and has been called the most significant breakthrough in the Palaeolithic (Nicolas Rolland in an article in Mellars 1990). Previous stone tool-making techniques had involved shaping an individual stone, or using the numerous sharp flakes knocked off it. Levallois involves thinking several steps ahead. It involves working a rock up until it can be hit on one end to knock off a very sharp flake with a predetermined size and shape. Tools of this type first appear between 200,000 and 400,000 years ago and become especially common in Late Middle Palaeolithic Mousterian cultures (Klein 1989). By then the technique had been further improved allowing a series of similarly shaped flakes to be taken off a single pebble (Roe 1971). The defence will show the jury Mousterian tools in map 13. A precise boundary between Lower and Middle Palaeolithic is very difficult to define (Stringer and Gamble 1993) but the timing and the area of development shows the Levallois technique was presumably invented by what have been called “Archaic Homo sapiens” (Homo heidelbergensis).

But once again there is not a good correlation between stone technology and different human types. For example the European Mousterian is associated with Neanderthal humans but in Africa, where the similar Aterian appears, the people are not Neanderthal. Another problem is that the Levallois technique didn’t make it across the Movius line either. The jury will later see that some early advanced-looking humans seem to have appeared in the East though. In other regions humans continued using Mousterian technology for many years after the Neanderthals disappeared. This again shows that technology is independent of genes. Advanced stone technology doesn’t necessarily represent a more advanced, or modern-looking, human type and a more modern-looking human type doesn’t necessarily have advanced technology.

But through much of Europe and the Middle East the Middle Palaeolithic seems to replace the Lower Palaeolithic rather than develop from it (Klein 1989). This probably indicates a population replacement in those regions rather than the adoption of a new technology by a resident population. We’ll return to this problem, and meet all the Middle Palaeolithic people again, in “Species or Not” [Homo heidelbergensis].

Upper Palaeolithic

The “Upper Palaeolithic”, the next division from about 40,000 years ago, is associated exclusively with modern humans, Homo sapiens. It is distinguished from the Middle Palaeolithic in several ways (Klein 1989). Tools included elongated stone flakes (called blades), end scrapers and burins. The people also cut, carved, polished and shaped bone, ivory, shells and antler. They were probably the first to use composite tools combining leather, wood, stone, bone etc. From these raw materials they constructed what can be called the first art. The cultures became much more varied regionally, and are much more elaborate, than are those of the Middle Palaeolithic. Fire-hardened clay artifacts appear in Central Europe about 28,000 years ago, and by about 20,000 years ago humans had available to them much of the technology used by the Stone Age cultures that managed to survive into historic times.

The Upper Palaeolithic also provides the first evidence for fishing and birding. Small blades (microliths) of a type used to tip arrows were in use at least 20,000 years ago, although they may have been attached to spears to start with. There is a rapid increase in their number through Africa and Eurasia about this time. This probably indicates a rapid expansion of a new technology (Klein 1989). And possibly genes. The earliest conclusive evidence for the bow and arrow occurs only much later. Bone spear throwers were in use by at least 14,000 years ago. By 12,000 years ago what is considered to be the world’s oldest pottery was being made in Japan (Klein 1989, and see “Pacific Population” [Lapita]).

France has provided a fairly clear idea of the sequence of the development of stone technology in Europe and, as the jury may have noticed, many names of technologies come from French sites. As it is the most studied, most complete and most easily understood, its sequence has influenced all European study of Stone Age cultures. This in turn has influenced the global view. In France an immigrant population introduced the Upper Palaeolithic suddenly and obviously.

In France modern humans (Cro-Magnon) brought in the first Upper Palaeolithic about 33,000 years ago. This new technology is called the “Aurignacian” (named after a cave in France, Aurignac). It probably came to Europe from the southeast via Turkey and Greece. John Wilford (Wade 2001) writes, “In the rest of Europe by this time, Dr. Trinkaus noted, modern humans had spread from east to west; there is no evidence that people could have crossed from Africa into Europe by way of Gibraltar”.

P. Allsworth Jones, quoted in Mellars (1990), gives the beginning of the Aurignacian as 43,000 years ago in Southeastern Europe to 34,000 years ago in Western Europe. The culture reached its peak in France about 30,000 years ago. By then there even appears to be a hybrid of Upper Palaeolithic Aurignacian and Middle Paleolithic Mousterian in parts of France. This is the “Châtelperronian” and the defence will remind the jury of this in “Neanderthals et al” [Aurignacian and Mousterian]. About 27,000 years ago a new culture, the Gravettian, replaced both the Aurignacian and the Châtelperronian in France. It has been shown that this new culture originated in Eastern Europe or Southern Russia (Clark 1969) and it seems to have developed independently of the Aurignacian. We’ll catch up with all this and study the separate origin of the Aurignacian and Gravettian in Part V “Conquest”.

Marcel Otte (Mellars 1990) sees technological continuity in England, Belgium, Germany and Southern Poland, from the Middle Palaeolithic Mousterian right through to later elements of the Aurignacian, and especially to the Gravettian. Also Clive Gamble (Cunliffe 1994) mentions that some distinctive Middle Palaeolithic stone tools are also “found in some of the earliest Upper Palaeolithic industries”. This continuity may indicate some genetic continuity or gene flow in that region. The defence will also remind you of this later in the trial.

Around 21,000 years ago the Solutrean appeared and is basically confined to France and presumably developed there. The next culture is the Magdalenian, which lasts from 16,500 years ago until 11,000 years ago. It expanded from France into areas of Northwestern Europe that were becoming ice-free at the end of the ice age.

Changing environmental conditions around the end of the ice age (Roe 1971, and Cunliffe 1994) had led to the development of what is collectively called the “Mesolithic” (Middle Stone Age). But we’ll leave that for now and come back to it much later in “The Last Point” [Islands Again].


Out-side Western Europe the Upper Palaeolithic’s development is not necessarily associated with the first arrival of modern humans or Homo sapiens. Change in the rest of the world is not straightforward. In many places modern humans used Mousterian or even more primitive stone technology for thousands of years before they adopted the Upper Palaeolithic. In many regions the Upper Palaeolithic appears and is then abandoned several times (Stringer and Gamble 1993). In fact it could be said that even in fairly modern times the Eurasian Upper Palaeolithic was yet to reach such people as the Australian Aborigines or the Khoisan of Southern Africa.

The Upper Palaeolithic seems to have first developed somewhere in the Middle East, South Central Asia or Southeast Europe 40,000 to 50,000 years ago. There is actually evidence for even earlier use of standardised bone artifacts and personal adornment in parts of Southern Africa though. These African sites have been variously dated at anywhere between 100,000 and 40,000 years ago. But it seems that in Africa the Upper Palaeolithic proper developed as a result of the introduction of a new technology along the southern edge of the Mediterranean Islands sub-point of the human star. In other words it’s a back migration of culture, and presumably genes, through the Middle East.

New technological ideas have always moved backwards and forwards around the world. Therefore it is a good bet that the Upper Palaeolithic had developed from the gradual diffusion of waves of technological change over wide areas. It was almost certainly not due to some sudden genetic expansion of a single small group of advanced humans. In other words, like the hand-axe of the Acheulean and the Levallois of the Middle Palaeolithic, there is not necessarily close connection in the Upper Palaeolithic between technological and genetic change. The defence will continue to show that many maps of human gene distribution seem to be related to the expansion of particular technologies or cultures though.

The defence suggests that in some ways we can regard technology as evolving in a similar way to organic evolution; diversification, then hybridising followed by selection. However, unlike most genetic change, advances in both technology and culture seem usually to occur where two or more of them meet and form a hybrid, rather than on a geographic margins of their individual distributions. Improvements in technology have then allowed particular genetic and cultural combinations to expand, often through regions already occupied by other humans (see “Indo-Europeans”). New technology has even allowed those with it to move into so far unoccupied environments or at least exploit different aspects of them (Pacific Population” [The Canoe]). In other words human groups have been able to separate ecologically in the same way the mallard and grey duck may be doing in New Zealand (“Species” [Ecology]). The time taken to then become either a stabilised hybrid or for one group to become extinct depends on the effectiveness of each group’s isolating mechanisms, or tribalism, and the mythconceptions they have evolved to support it. It can take centuries for different groups to mix, and then divide into a new set of tribes with a new set of mythconceptions.

Technological evolution has made our evolution different from that of other animals. Changes in technology have given humans more adaptability and mobility than is usual within a species. The defence suggests that if not for changing technologies human populations would have developed greater regional diversity than they have. Various groups would have each become genetically the best adapted to their particular environment and would have remained in that particular region, effectively excluding other types. In time they may have diverged enough to become separate species.

“Single origin” supporters believe this is in fact what has happened, in that separate human species have kept replacing earlier species. But humans, even more than most other species, usually show a remarkable willingness to hybridise and to form new combinations rather than to diversify into separate species. Supporters of the “spread origin” theory believe this willingness goes back a long way.

Movement of groups of people bringing new technology into new regions has offset tendencies to genetic isolation within the human species. All advances in technology have effectively meant times of plenty and led to environmental or ecological change. At such times the population increases, boundaries become porous and hybrids are able to form and survive. Selection then acts on these hybrids and various genes, including mtDNA and Y-chromosome lines, become extinct (“Pedigrees” [Ancestry]).

As in the example of the Pacific Islands, advances in technology have allowed humans to expand at times into more hostile environments. People with Upper Palaeolithic culture were able to move rapidly into Northeastern Europe and Siberia (see “North to Alaska”) and then to America. But the Mediterranean Islands and Island Southeast Asia and the Pacific, the last two sub-points on the human star, were not settled till more recently.

The defence suggests that males carrying new technology have contributed to the distribution of the Y-chromosome variants. Incoming variants often replace pre-existing ones. As the defence pointed out in “Polynesian Origins” [Societies] in most cases, and especially until relatively recently, women (mtDNA) transmit most elements of culture between the generations. Therefore as a rule of thumb: Y-chromosome distribution reflects technological waves of expansion, mtDNA distribution reflects cultural waves of expansion, and nuclear DNA reflects the combined result of these with elements already present in particular regions. The three genetic lines are surprisingly different in their history (Wade 2001). In fact, as the defence said in “Pedigrees” [Selection], we could go further and say, “each gene has its own evolutionary history” (Karafet et al 1999), anyway it “has a separate ancestor” (Jobling et al 2004).

See next :: Human Evolution on Trial : 'First Humans'

Witnesses Called

Burke, James (1978) Connections. Macmillan, London Ltd.

Clark, Grahame (1969) World Prehistory. Cambridge University Press, UK.

Cunliffe, Barry ed. (1994) The Oxford Illustrated Prehistory of Europe. Oxford

University Press, Oxford.

Jobling et al (2004) Human Evolutionary Genetics. Garland Science, New York.

Johanson, Donald and Edey, Maitland (1982) Lucy. Warner Books, New York.

Karafet et al (1999) Ancestral Asian Source(s) of New World Y-chromosome Founder Haplotypes. Am. J. Hum. Genet. 64: 817-831.

Klein, Richard G. (1989) The Human Career. University of Chicago Press, Chicago.

Mellars, Paul ed. (1990) The Emergence of Modern Humans. Edinburgh University

Press, Great Britain.

Roe, Derek (1971) Prehistory. Paladin (Macmillan and Co. Ltd.), London.

Stringer, Christopher and Gamble, Clive (1993) In Search of the Neanderthals. Thames

and Hudson, Great Britain.

Tattersall, Ian and Schartz, Jeffrey H. (2000) Extinct Humans. Westview Press, New York.

Wade, Nicholas ed. (2001) The New York Times Book of Fossils and Evolution. The Lyon Press, New York.

Zilhão, J. et al (2006) Analysis Of Aurignacian Interstratification At The Châtelperronian-type Site And Implications For The Behavioral Modernity Of Neandertals

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