This book deals with major migration episodes in human prehistory that can be reconstructed using multiple and independent sources of information. Whatever the information source, understanding of the prehistoric human past requires that hypotheses be considered against available information. I have presented one such hypothesis earlier, namely that demographic growth can drive migration. It can also be suggested that specific developments in technology, clothing, shelter and subsistence allowed many episodes of population growth and migration to occur, for instance by hunter-gatherers into Arctic latitudes or by early farming populations looking for fertile new lands in which to plant their domesticated crops or graze their animals. The sources of such hypotheses can either lie within recovered data (which are sometimes extremely few, especially if we rely on the archaeological record alone), or they can be drawn from broad comparative considerations of human behavior in the historical, ethnographic, and modern worlds. In reality, they are drawn from both approaches.
For instance, a major hypothesis, used in the later chapters of this book, is that many major language families and their early human speakers migrated together, on many separate occasions in different parts of the world, following the adoption of systematic food production during the Holocene.5 This early farming dispersal hypothesis is based on worldwide comparisons of archaeological, linguistic, genetic, and other scientific data. It is also based on detailed region-specific archaeological and biological evidence. My general approach in developing and assessing such hypotheses follows Fogelin's (2007) strategy of “inference to the best explanation,” by eliminating explanations that are less well supported by the evidence. I hope that my chosen explanations, especially for migrations during the past 10,000 years, will also accord with Fogelin's call for explanations that are empirically broad, general, modest, conservative, simple, testable, and that address many perspectives.
There are two further points that I wish to make here in order to set the concept of prehistoric migration in a fuller context. Firstly historical accounts inform us that many relatively recent situations that we tend to think of as 'migrations' had, in reality little long-term impact on the subsequent genetic, linguistic and cultural patterns in the areas to which they penetrated. This was because the migrants/conquerors and their descendants existed in relatively small numbers and were absorbed into the larger indigenous communities around them. The populations of many ancient conquest hegemonies and empires met this fate, including those of the Hellenistic kingdoms in Asia and Egypt following the conquests of Alexander the Great, many of the Germanic and Turkic-speaking populations who migrated across continental Europe during post-Roman times, the
Vikings in continental Europe, the Normans in England, the Crusaders in the Levant, the Mongols across their vast Eurasian empire, and many European colonial states in tropical Africa and Asia.
Conquest, imposition of government, and taking of tribute can have dramatic short-term effects, but over the long term many such events left few permanent traces, especially in terms of language replacement. Despite the magnificent conquests of Alexander the Great, and a few centuries of Greek influence in central Asia, hardly anyone living outside Greece and Cyprus today, except for modern migrants to countries like Australia and the United States, speaks Greek as a first language. Examples such as these can tell archaeologists that while material culture and imposed forms of government can often spread far and sometimes have significant cultural impact, they do not necessarily have to be associated with significant levels of permanent migration.
My second point is more philosophical, and it concerns the concept of origin. Let us consider two populations who have achieved fame in the world record of ethnography - the Khoe-San populations of southern Africa and the Maori of New Zealand. The Khoe-San, according to current archaeological and especially genetic data, have an ancestry in southern Africa that extends back for at least 100,000 years, perhaps as much as 300,000 years if one accepts a set of new molecular clock genetic calculations for the antiquity of the modern human genome.6 The ancestors of the Maori arrived in New Zealand in the twelfth or thirteenth century ad, at a time when many famous monuments of Medieval Asia and Europe were under construction. We might rightfully think of the Khoe-San peoples as 'old' in ancestry and therefore origin, and the Maori as 'young'. Yet both groups are equally as modern, in human biological terms, as the rest of us. Both have prehistories of equal length, going back into the foundation layers of human origin in Africa. The only real difference is that the Khoe-San developed as distinctive populations within a completely African environment, whereas the Maori developed via many episodes of migration and ancestral residence, through at least 50,000 years, in many parts of tropical Asia and Oceania. Khoe-San ancestors tended to stay at home, Maori ancestors tended to migrate and sail away over the horizon in canoes.
In this sense, the 400 years or so of Maori residence in New Zealand, prior to the European discovery of these islands by Abel Tasman in 1642, are little more than a veneer. The Maori arrived in New Zealand as Polynesian fisher-farmers around ad 1250, just as complex in cultural terms as they were on the eve of the first serious European arrival, in 1769 by the British explorer James Cook (Tasman did not land). It is for this reason that my perspective in this book is focused on human populations and the routes they have traveled through time and space, and not simply on the archaeological records of modern nations. There is far more to Maori population prehistory over the long term than the prehistory of New Zealand, even if we cannot recognize entities in the lands of ancestral occupation, in Africa, southern China, Southeast Asia, or Oceania, that can specifically be termed Maori, as opposed to less specific categories such as modern human, Neolithic, Austronesian, or Polynesian (see Chapter 8).
World History
