Saturday 20 June 2009

Human Evolution on Trial - North to Alaska

Human Evolution on Trial - North to Alaska


Patricia Anderson-Gerfaud’s study of wear on stone tools from the European Middle Palaeolithic Mousterian (Mellars 1990) has shown at least some were used to prepare animal skins. Neanderthals must therefore have used hides, probably as some sort of cloak or shelter. But most of the tools were used to scrape or shape wood and other plant material. Therefore Middle Palaeolithic Neanderthal people probably used wooden spears.


The big break is in the Upper Palaeolithic, during the Gravettian, (PPT) when someone got the idea of connecting the stone to the wood. It’s possible end-on hafting was used in Middle Palaeolithic times (D’Errico 2005) but evidence for its use is much stronger in the Upper Palaeolithic. Certainly no one had thought of lateral hafting until as late as the Gravettian.



Improvements in technology meant more people could live in any particular region. Advances in technology also allowed people to gradually exploit resources that lay further to the north than they had previously been able to reach.


The Ice Age


The popular idea of the ice age is that huge sheets of ice covered all regions north of about 50° latitude. Snow often accumulates on mountains, and moves down them as glaciers. During ice ages all that happened was that glaciers got bigger and new ones formed at lower altitudes. Some glaciers did expand onto plains, but their source was still usually higher country. The result was that the mountains shown as barriers on the maps the defence has presented during this trial simply became more effective barriers. Cold, rather than just ice, had always been the main barrier to human movement northward.


At first modern human expansion north would have been gradual. They probably arrived in Southern Russia through the region today called Iran and Afghanistan. Neanderthals already occupied at least part of this region and so there must have been contact, and possibly breeding, between the two populations for a very long time. In fact evidence of hybrid cultures and technologies similar to those mentioned for Europe in “Neanderthals et al” [Aurignacian and Mousterian] have been found through Turkey, Eastern Europe and the Middle East (Steve Kuhn quoted in Wright 2002).


Neanderthals had presumably developed some cultural method of surviving cold weather (possibly skin shelters), *(see also 'La Folie') as well as being genetically (and thus physically) adapted to it. It’s possible that resident Neanderthals also had a better stone-working technology than did the incoming modern humans. Incoming modern humans had a pretty basic stone technology but were skilled at using bone and antler. The combined technology provided an ecological advantage for any groups with it.


Modern-looking humans had occupied Asia as far north as 50° by about 40,000 years ago. There is no evidence for sewn skins until bone needles appear about this time. The two facts are probably related. Sophisticated, eyed, bone needles were certainly being used by 19,000 to 18,000 years ago. The oldest evidence for the killing of fur-bearing animals, presumably for warm clothing, is found in European Russia about 22,000 years ago (Klein 1989). Sewn skins probably also provided housing, as they did for the Plains Indians of North America until a hundred and fifty years ago. Clothing made of fur and skins sewn together is a lot warmer than loincloths. The development of efficient clothing meant people could begin moving further north than 50° N.


Warm clothing and efficient spears meant the mammoths and woolly rhinoceros on the tundra were no longer safe. Again it was the prehistoric equivalent of winning a lottery (“Pacific Population” [The Canoe]).


The Gravettian


Several technological developments seem to first appear in Eastern Europe. There is abundant evidence the Gravettian culture developed there and had spread west as far as Southern France by 27,000 years ago. Almost certainly it had developed totally independently of the Aurignacian of Southern and Western Europe.


The Eastern European Gravettian probably developed at the western margin of a group of mammoth hunting Southwestern Russian people. Efficient mammoth hunting probably originally developed somewhere on the Central Asian steppe and then spread to other regions. In Southwestern Russia mammoth extinction is dated to about 30,000 years ago, near the end of a relatively warm phase of the ice age (“Neanderthals et al” [Climate], and “Extinctions” [What Have we Done?]). Mammoth hunting implies the presence of fairly large groups of people, at least seasonally. A dead elephant can feed a lot of people at one time. It may actually have been mammoth hunting that ultimately led to the Upper Palaeolithic population explosion and subsequent cultural flowering.


A look at any map will show the jury that once humans moved north beyond 50° mountains would split the northward movement into three prongs. From the west they are Europe, Central Asia, and East Asia. The Ural Mountains isolate Europe, and mountains in Central Asia would have made it difficult for technological innovations on the northern margin of any expanding human population to reach southward into what are now China and Mongolia, the East Asian point.


In the Far East, early mammoth hunters had entered the North China tundra, perhaps via the Tarim Basin and Mongolia. There they too had probably mixed with any pre-existing population. Mammoths were hunted in China by 35,000 years ago, but their eventual extinction is associated with a relatively primitive stone technology. The Upper Palaeolithic proper was introduced only a fair bit later,and then mostly from the north, apparently (Clark 1969).


The earliest, but controversial, evidence for people beyond 50° N in Central Asia is also dated at 35,000 years ago. These sites are in the Lena Valley at about 60° N. Anyway human occupation is well established in the southern Yenisey and Ob Valleys by 20,000 years ago (Klein 1989).


Humans may also have been in Alaska by 20,000 years ago. During the ice age land, known as the Bering Land Bridge, connected Alaska to Siberia but mountains and glaciers seem to have prevented any mass human movement further into America until about 13,000 years ago.


The tools in the upper left of map 19 are Gravettian and at left Aurignacian (Rowe 1971). The other tools have also appeared in earlier maps. For example the defernce presented East Asian microlithic tools as evidence in “Polynesian Origins” [Japan] (map 4).




First of all the map shows the movements into Australia (numbers 1 and 2). You can see from this and the following maps why the pre-European Australians became genetically and technologically isolated from humans in the rest of the world.


Number 3 is the centre of the Ethiopian (or Aden) expansion and includes the branch the defence has suggested moved into southern Europe and gave rise to the Aurignacian (“Out of Africa” [The Middle East]). Number 4 is the centre of the eastern or Indian expansion also mentioned in “Out of Africa” [Genes Again]. I would like to suggest it eventually gave rise to the Gravettian.


Number 5 is the early mammoth hunters. The eastern end of this expansion mixed with earlier populations in the star’s East Asian point. They developed into the modern East Asian human type. I suggest these eastern mammoth hunters spoke a language that ultimately gave rise to such languages as Burushaski, Ket, Sino-Tibetan, Austric, Na-Dene and some Georgian languages.


Number 6 is the later Upper Palaeolithic people, including the Gravettian proper. I’ll explain soon why I believe that by the time of this expansion the language could be called pre-Eurasiatic (see “Culture” [Languages]). Movement of these pre-Eurasiatic-speaking people probably introduced the microlithic culture into Northern China but, as the defence showed in “Polynesian Origins” [Japan], the technology moved much further south, probably again transmitted in a similar way to that suggested for the chariot in “Indo-Europeans”.


Greenberg and Ruhlen (1992) consider that most American Indian languages share a common origin (see Change” [Variety Through Space]) and that they are related to a Eurasiatic superfamily (“Indo-Europeans” [Indo-European Languages]). The defence suggests therefore that the people first able to move beyond Alaska into America through a gap in the glaciers spoke dialects of pre-Eurasiatic.


The First Americans


Most early human fossils discovered in North America, such as “Kennewick Man”, have a more European look than we would expect if they had come only from East Asia (Olson 2002).


And concerning the modern population Tim Flannery (2001) writes “Few Indians, for example, possess the fold of skin over the corner of the eye that is such a striking feature of most modern people from north Asia. A further difference is found in the fact that many American Indians have prominent noses and narrow faces, while most contemporary north Asians have small noses and broad faces”.


It has been suggested the Asian population’s physical appearance must have changed since the American Indians’ ancestors left. But the jury will soon see there is a much simpler explanation. Dr. C. Loring Brace of the University of Michigan has shown by skull measurements that the original inhabitants of America closely resembled the modern Ainu from Northern Japan. Many people believe the Ainu themselves contain a mixture of European and Asian genes.


The defence suggests the American Indians may also be a mix of two populations.


In “Out of Africa” [Asia] the defence mentioned the controversial evidence for very early human arrival in America. Evidence from nuclear DNA does suggest the American Indians split from the rest of the world 31,000 years ago (Cavalli-Sforza et al 1994). Such studies of the genetic distance between different groups of people are useful to calculate their time of separation if there has been no input from any other population.


But the wave theory tells us that if a particular group is actually a hybrid population, a product of the mixing of two populations, genetic distance will be distorted. Genetically the hybrid population will be closest to the group that has provided most of its genes. The hybrid population will appear to have separated from it. But genes contributed from any other group will give the appearance the hybrid population had separated much earlier than it did in fact form. For example, by comparing just nuclear DNA Polynesians are shown to have separated from other groups of people 26,000 years ago. This date is usually considered to be the result of the Polynesians being a hybrid of East Asian and Melanesian people.


It is my bet that at the height of the ice age a group of people who had evolved somewhere north of latitude 50° swept west and east through the tundra. As well as sewn skin clothing, they carried the microlithic technology (see Polynesian Origins” [Japan]), and possibly birch-bark canoes made on a frame of branches. Men probably led the way. Wherever they originated they were able to be the first people to enter Northeast Siberia. As they had moved east through unoccupied Central Asia these tundra people would have occasionally met and mixed with early mammoth hunting East Asian people they met through gaps in the mountains to the south. The eastward-migrating population became a mixture of people from the two points of the star closest to America: Northwest Europe and East Asia.


Genetic Evidence


We’ll start with American Indians’ male ancestry. A study of mutations on the first Americans’ Y-chromosomes has revealed the vast majority, nearly ninety percent, are either descended from, or the same as, those that outside America are most commonly found in just two small groups of people. They are known as the Selkups and the Kets (Karafet et al 1999) and they live next to each other in Central Siberia north of about 55° N. The Y-chromosome line is Q (see “MtEve” [The Trees]). A later series of movements north of more southerly Y-chromosome variations (N, O and C) has isolated and diluted a remnant Northeast Siberian Y-chromosome Q population and separated them from the Selkup / Ket. Remember there have been several expansions of technology, genes and presumably Y-chromosomes from around the Australian point. Y-chromosome line Q is most closely related to the widely distributed line R. Lines Q and R separated from each other long ago though, presumably on the Central Asian steppe.


Although Selkups and Kets share genes, and a very similar culture to each other, they speak languages from two totally different families. The original migrants to America need not have spoken either of these languages though. Pre-existing populations in the region could well have more recently independently adopted both these languages.


The Selkup language group can wait for a while [Neighbours]. I suspect that the Ket language has replaced an earlier pre-Eurasiatic language. It was introduced to Central Asia along with boat-using technology from the Sea of Japan (Polynesian Origins” [Japan]). We’ll look at genetic evidence showing a connection with an expansion from Japan soon. But the jury has seen many times that technology and language spread further than genes. Ket is today confined to the Yenisey River valley but the area where it and related languages are spoken has been shrinking historically (Slezkine 1995). We’ll look at the reason for this soon [Eurasiatic]. The language group was obviously spread over a much wider region at some time in the past. It may have been part of a dialect chain or cline of languages spread from Japan to Georgia. Burushaski may be part of this cline.


Karafet et al (1999) refer to another study showing that, unlike the Y-chromosome, American Indians’ mitochondrial DNA lines (A, B, C and D) originate south of latitude 50°. In Mongolia, Tibet, Northern China and Korea, although one mitochondrial DNA line has since been discovered that may have an ancient origin in Europe (Jones 2001).


This is yet another example of the independence of Y-chromosome and mtDNA. The defence interprets it as showing that Asian women had occasionally joined the Eurasiatic-speaking people’s expanding eastern margin. But this advancing wave absorbed their descendants. The original pre-Eurasiatic language was maintained. The pattern is different to that mentioned for Polynesian Origins” [Genes]. In Northern Asia gene flow would be preceded by the line, “Here love, cook up this mammoth steak and come with me”. Hybrid vigour was maintained.


Later Migrations


Two other Asian migrations added to the pre-European population of America, although there was probably more overlap and continuity between all three than was once thought (Jones 2001). The Na-Dene people are the earlier of these later two and, as the defence suggested in “Polynesian Origins” [Na-Dene], they too were probably connected to an expansion from the Sea of Japan. Greenberg and Ruhlen (1992) believe Na-Dene, as well as being distantly related to the Sino-Tibetan family and so to Austric, (pdf) may be even more distantly related to several isolated languages in Asia such as Ket, Burushaski, (pdf) the Georgian languages and even with Basque /Euskara in the Far West of Europe. Many languages spoken in India, including possibly Nahali, are almost certainly related to East Asian languages.


At this stage the defence would remind the jury of Cavalli-Sforza’s map of the third principal component of Asian genes (map 4 in “Polynesian Origins” [Japan]). It does hint at some genetic movement from the Sea of Japan across Asia to the Caspian Sea and Turkey. A further expansion to the Atlantic coast from the Black Sea (number 2 in map 20) shows up in the sixth principal component for Europe (coming up later, map 23). We’ll come back to this end of the expansion and look at pottery and axes next in “The Last Point”.




The Inuit, or Eskimos, are the third pre-European migration into America and are very similar genetically and linguistically to East Siberians (see map 21). Their languages form two twigs on a branch of the Eurasiatic super-family tree (see “Culture” [Languages]).


Eurasiatic


The Eurasiatic languages presumably developed north of at least latitude 50° but technological or cultural advantage has meant they have been able to expand back south and replace other languages. Their expansion may be responsible for the modern human narrowed genetic variety, especially the Y-chromosome, particularly in the Northern Hemisphere. In fact apart from Ket, and the Na-Dene languages of North America, virtually all languages found north of about latitude 40° today belong to or are related to the Eurasiatic super-family of languages. Some non-Eurasiatic languages such as Basque, Caucasian, (Georgian), Burushaski and, till recently, Ligurian and Etruscan (“Indo-Europeans” [Mingling]) managed to survive but only in isolated mountainous regions.


As it expanded the Eurasiatic super-family broke into various language families, a series of language chains or clines.


Number 1 in map 21 is a non-Eurasiatic African language group, Niger-Kordofanian. Speakers of this language family have expanded relatively recently as far as South Africa (“The Human Star” [A Map]). All the other languages belong to, or are probably closely related to, the Eurasiatic super-family. Sort of clockwise from the Northwest European point they are 2 Indo-European, 3 Finno-Ugric, 4 Altaic, 5 Chukchi-Eskimo, and 6 Ainu and Gilyak. In fact Gilyak is sometimes not classified as Eurasiatic but is probably the remnant of an early expansion of the language family. I suspect both Ainu and Gilyak arose from a single language spoken on the coast of Asia north of Japan but they separated from each other soon after the expansion of proto-Eurasiatic. The American Indian languages (number 7) are also not technically Eurasiatic but are probably related to it (Greenberg and Ruhlen 1992).




Neighbours


Number 8 combines the Dravidian languages of India with the neighbouring extinct Elamite language of Iran, because they may be related to each other (Mallory 1989, and Cavalli-Sforza 1995). They, along with number 9 Hamito-Semitic, may also be part of a pre-Eurasiatic cline. But while conceding it’s possible the Hamito-Semitic and Elamite / Dravidian groups are distantly related to each other, some people believe they may be more closely related to other languages than to Eurasiatic. They may have a connection to Basque (Greenberg and Ruhlen 1992), or even with the Austric group. That’s why I put them between these groups when I constructed the language family tree in “Culture” [Languages]. I will suggest the region where the Hamito-Semitic and Elamite / Dravidian language families both originated in The Last Point” [Islands Again].


The terms Semitic and Hamitic are derived from the names Shem and Ham, two sons of Noah (of the Ark fame). By tradition all other people, and presumably their languages, are descended from Noah’s third son, Japheth. Hamito-Semitic is usually called Afro-Asiatic these days but whatever the name the languages within the group are all fairly closely related. They separated relatively recently. Languages within the Semitic branch are all especially closely related. They include Arabic, Hebrew, Canaanite, Phoenician, the Biblical language Aramaic and the ancient language Akkadian. As the defence said in “The Human Star” [A Map] various groups across North Africa and into Ethiopia speak Hamitic languages. Any earlier diversity of the Hamito-Semitic languages has been obscured by the relatively recent expansion of Islam. This has carried Arabic far beyond its original home.


The wave theory tells us that neighbouring Eurasiatic language dialects would also soon have split into separate languages, and each language would in turn form more dialects.


For example proto-Altaic would have developed from proto-Eurasiatic, probably in the higher country in East Central Asia. The proto-Altaic language then broke up into the Korean, Japanese, Manchu, Mongolian, Tungusic and Turkic languages, although the language that gave rise to the first two probably branched off early. Japanese and Korean are sometimes not classified as Altaic although they are usually included in Eurasiatic. The Altaic language group eventually displaced virtually all pre-existing languages in East Asia to as far south as the magical 40° N. We looked at Altaic’s shifting western margin way back in Part II (Indo-Europeans” [The Chariot]).


Yuri Slezkine’s 1995 book “Arctic Mirrors” contains maps of historical language distributions in Siberia. These provide a good clue to the movement of people around the region. For example the distribution indicates to me that Tungusic is a fairly recent northward expansion of the language group. This has separated a different member of the Eurasiatic superfamily, the Finno-Ugric group, into a western (North European) and an eastern group (Yukaghir). The Selkup language the defence mentioned earlier [Genetic Evidence] is a member of the Western Finno-Ugric family. We also looked at The Finno-Ugric family’s western neighbours in Part II (“Indo-Europeans” [Mingling]). The eastern Finno-Ugric group survives in the semicircle enclosed by the Verkhoyansk and Kolyma Mountain ranges in Northeastern Siberia.


The point of all this has been to again emphasise there has been a huge swirl of genetic, technological, cultural and language movement since mtEve existed. Perhaps it has sped up a bit, but you have seen that it almost certainly happened long before her time. It even happens in other species. This evidence further supports the wave theory of genetic, cultural and technological evolution. We have finally arrived at the last point and it’s time to explore the Mediterranean Islands.


See next :: Human Star - The Last Point


Witnesses Called


Boeree, George C., 'Language Families of the World' (illustration)

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Wright, Karen (2002) Neanderthals Like Us. Discover, Vol. 23 No. 3.

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