Symbiotic and Convergent Cultural Evolution: An Archaeological Perspective, with Two Examples

Another essay written for my undergraduate degree in Archaeology – at this time I was getting into evolutionary theory and seeing how it could be used for theory-building and explanation in archaeology.

Romans in Britain and Celts in Thrace

Speculation on how one culture affected the development of others has always been a part of archaeology, and often a leading part. In a number of well-documented cases archaeology forms the main evidence for issues of cultural identity and change, domination and resistance.

In this study I wish to examine cultural interchange through an evolutionary model, and then examine how this model aids our interpretation of the past through the use of two examples, the Romanization of Britain and the invasion of the Scordisci, a Celtic tribe, into the area of the Triballi, a Thracian tribe.

Cultural Change and Evolution

The concept of evolution has found variable favour with archaeologists, usually in accordance with contemporary theoretical paradigms found in the broader context of the social sciences. A sharp division has in fact existed from time to time between those archaeologists espousing cultural evolution and those upholding historical particularism (which argues that culture is ‘a unique product of its own largely fortuitous historical development (Trigger 1993, 2). Put another way, theories are divided as to whether it is the differences or the similarities between cultures which are important (ibid.). Both stances are partially right, partially wrong, a fact which is increasingly being acknowledged, along with many other shortcomings in the approach of the social sciences. By taking a closer look at how evolution is described in biology, it can be shown that the adoption (or adaption) of this term by the social sciences have previously misused and/or misunderstood it. (Harris 1998, 2-3)

As I have argued elsewhere, the theory of evolution applies as much to human cultures as to animal species, and that evolutionary processes can satisfactory describe cultural change. For the present study, I will be focusing on two forms of co-evolutionary processes, symbiotic and direct convergent evolution.

Before I begin the discussion of cultural co-evolution I will explain some important details of the interpretative framework of evolutionism applied to human cultures.

Firstly, I follow a view of evolution proposed by the philosopher Karl Popper who advocated a Darwinian theory. Briefly, his theory is that evolution occurs through problem-solving; the situation an organism finds itself in will consist of certain problems (e.g. survival, food procurement, reproduction) and the physical (biological) and behavioural (cultural) inheritance of the organism represent past solutions to these problems. Survival of the fittest, in these terms, is survival of the best problem-solvers.

Secondly, I feel it important to note that evolutionary processes are a discourse between species- (or cultural-) level alteration and the actions of individuals; ‘At the heart of evolution is a paradox; for evolution “is absolutely a phenomenon of populations. Individuals and their immediate descendants do not evolve. Populations evolve, in the sense that the proportions of carriers of different genes change through time” (Wilson 1993, 75). However, the population of the next generation of a species is (under natural conditions) composed only of the genes of those individuals in the present population who manage to successfully reproduce. Thus evolution takes place on the level of the species level but is dependent upon individuals’ (Harris 1998, 4). Seen in the context of human cultures, this distinction becomes more complex; the place of concepts such as ‘species’ becomes vague when analyzed in human terms. I suggest a system of cultural cladistics which recognises a range of definitions, from the broadest level of biological species (Homo sapiens) to the opposite extreme of the single organism (human individual). Between these two, we find (from top to bottom), culture groups, cultures, and various group levels according to internal cultural divisions. The more socially stratified or complex a culture is, the greater the number of groups it is likely to contain. Each group is symbiotically united with the others (a single culture is interdependent) but will have its own interests and may therefore act as a distinct evolutionary unit. A single individual may be a member of many different groups relating to political, economical, ideological, and kinship divisions within their culture. An individual will make choices in their behaviour given the context of the situation and the role in which they enter the situation. An individual may react very differently in an intra-cultural situation to an extra-cultural one.

Finally, it must be pointed out that this evolutionary model provides only a description, not an explanation, of the past. It is a way of viewing cultural change within an epistemological framework. From the description provided by evolutionism, however, we can move to make a better informed interpretation, based on our understanding of individual behaviour (psychology) and cultural behaviour (anthropology and sociology).

Symbiosis is broadly defined by biologists as ‘the intimate association of two or more species’ (Wilson 1993, 176). Such associations are formed as part of usual evolutionary processes, or, in terms of the evolutionary view adopted here, during the course of finding solutions to situational problems. Convergent evolution exists in two forms; indirect and direct. Biologists use the term only in the indirect sense, where it means ‘the occupation of the same niche by products of different adaptive radiations, especially in different parts of the world’ (ibid,, 95). Direct convergent evolution is a term created here to describe the evolutionary uniqueness of human cultural change; unlike biological species, which once totally distinct will always remain distinct (evolution cannot be reversed, it cannot ‘go backwards’), two distinct human cultures can merge to become one, regardless of their relative difference at the time of first contact. Thus, two cultures can show indirect convergent evolution only when they are not together; the term highlights a similarity between cultural forms due to ecological (environmental and cultural) similarities. The two cultures remain distinct. With direct convergent evolution two cultures through interaction become one; a symbiosis taken to its conclusion with the distinction between the two groups vanishing – there are no longer interdependent but the same.

Seen in cultural terms, co-evolution occurs between neighbouring cultures or expanding cultures meeting and inter-penetrating cultures pre-existing in the area expanded into. The relationship which forms between two meeting cultures, and the result of this relationship, will be determined by the structure and character of the respective cultures.

I will give two examples of cultural co-evolution, one of symbiotic and one of direct convergent evolution, explaining the difference by reference to the particular cultures involved in these relationships.

Romans and Britons to Romano-British

The ‘romanization of Britain’ has a long history in archaeological thought, although presently such terms as ‘romanization’ are disfavoured due to the imperialistic cultural bias implied by their use (e.g. see Hingley 1996).

Caesar landed twice in Britain, in August 55 BC and July 54 BC, although the formal conquest of Britain did not really begin until the Claudian invasion of AD 43 (Ellis 1990). The conquest was never completed; the most northern parts of the country may have suffered Roman invasion but Roman control was not formally achieved in these regions. Britain’s part in the Roman Empire varied through time as the fortunes and rulership of Rome varied, and as the internal dynamics of Romano-Britain and its specific relationships with non-Romanised outsiders (e.g. Irish and Germanic raiders) varied. Roman rule is formally acknowledged to have ended around the turn of the 5th century AD.

To understand the relationship between the Romans and the British one must understand these cultures. It should be immediately noted that while the Romans were unified under a Republic and later an Empire, the British had no such unity, but instead consisted of a number of similar but distinct groups, generally termed tribal. A second point which follows from this is that the interconnections between these tribes extended across the channel to Gaul. Furthermore the British tribes were entwined in trade networks which linked them to the Mediterranean. The Romans and British were therefore interacting (if only through mediaries) long before any Roman had stepped foot on British soil.

Conflict between Rome and Britain was not unavoidable, although the country did harbour Gaulish enemies of Rome (Ellis 1990). The impetus for Roman expansion was not ‘a simple one derived from a systematic expansionist design. It was rather a complex of motives, the roots of which lay in the highly competitive system of power within Roman society; a system where instability was endemic and power concentrated in the hands of an oligarchy. Moreover, the personal political and economic fortunes of this group were closely bound up with their success in the military sphere’ (Millett 1990, 2-3). Although the Roman army was composed of thousands of individuals with a range of social and ethnic backgrounds, they constituted a unified group (an evolutionary unit) under the leadership of a centralised elite (or an individual member thereof).

The British tribes were divided between pro- and anti-Roman groups (Ellis 1990). ‘Conquest offered new opportunities to some members of the elite for domination and social control, but may have provided a threat to the liberty and security of some agricultural producers. Conversely, some members of the elite may at times have felt threatened by changes in society, and the Roman army certainly provided an escape from agricultural drudgery for some native males’ (Hingley 1996, 44). Within a particular tribal unit feelings could be split between individuals in accordance with what they stood to lose or gain by the Romans. The Romans encouraged collaboration by granting favourable terms to allied tribes and punitive terms to tribes which resisted their rule.

Once the Romans had succeeded in dominating an area they preferred to maintain control through the native elite, leaving basically intact the indigenous power structure. The cultural changes which followed incorporation into the Roman Empire – the process referred to by the term Romanization – were a reflection of a re-orientation of cultural identity and the modified political, economical and social horizons which were the consequence of this incorporation. Seen in this way, it becomes clear that the British Celts did not really become Roman (they did not move to Rome) but they adopted aspects of Roman culture (language, dress, architectural, prestige statements) as it suited them. Likewise the conquest of Britain must have been felt in Rome, both in terms of political, social and economic consequences and in terms of the cultural identity of Rome, but Romans did not become British. ‘Romano-British’ does not therefore mean ‘Roman’ and ‘British’ but a distinctly Roman Britishness, or British Romanness.

Once peaceful control of Britain had been achieved, the Romans and the British were involved in a symbiotic relationship, so that the eventual collapse of one (Rome) may have resulted in disaster for the other (the Anglo-Saxon conquest of England), and certainly led to a drop in ‘Romanness’.

Celts and Thracians to Thraco-Celts

Around 300 BC a Celtic army, probably consisting of a number of Celtic tribes, moved down the Balkan peninsula towards Greece (Ellis 1990). Later, components of this army were to sack Delphi

(ibid.), but it is not this event which concerns us here. What is of relevance is the Scordisci (a Celtic tribe) and their co-evolutionary relationship with the Thracian tribe, the Triballi.

Initially the Scordisci settled beside the Danube, and their territory stretched from southern Hungary down into Yugoslavia (Kaul 1991). Conflict between the Scordisci and the native inhabitants appears to have taken place but ended after a while, and ‘there was rapid integration of Celtic features into the local culture’ (ibid., 37). ‘Archaeological finds show that in the first half of the 2nd century BC, the Celtic culture from Yugoslavia made inroads into neighbouring northwestern Bulgaria’ (ibid.). This area was the homeland of the Thracian tribe, the Triballi.

The archaeological record from this area, at this time, witnesses the ‘Padea-Panagjurski Kilinii group…. [in which is found] burials containing typical Celtic warrior’s equipment, but lying under barrow according to the local tradition and with Thracian pottery and harness bit-types… Some graves show predominately Celtic features, whilst others have a much more pregnant mixture which makes it difficult or impossible to define the individual graves as either Thracian or Celtic (Kaul 1995, 25). From an archaeological point of view, at this point the two cultural influences had become indistinguishable; there was no longer two recognisably distinct influences. In the historical records we find that the Scordisci and the Triballi ‘had a legend about a common mythical origin’ (ibid., 26), that the Scordisci ‘to a certain extent took over the Triballi’s name in the eyes of the classical authors’ (ibid., 25), and also that the Scordisci were reported to follow the Thracian tradition of using skulls as drinking cups (Rankin 1996).

Similarities existed between Celtic and Thracian cultures (Rankin 1996), both in the form of social customs, such as inter-elite marriages, and in their ’embedded’ social structure wherein social relations were not able to be separated into distinct economic, ritual or kinship categories (Hodder 1979), which would have aided their acculturation – direct convergent evolution – into a single ethnic group. The term ‘Thraco-Celtic’ can appropriately be applied to this culture in the same way as the term ‘Romano-British’ was used above. One of the most intriguing and discussed artefacts of the archaeological record has been attributed to this Thraco-Celtic culture; the Gundestrup Cauldron (Kaul 1995, Taylor 1992).


I have presented here a general argument for an evolutionary model of human cultural change, and illustrated how such a perspective can be applied to the archaeological record by reference to two examples, the Romanization of Britain and the Celtic invasion of Thrace (or, rather, a particular episode thereof).

I have used different evolutionary terms to describe the events which occurred in each case; the first example demonstrated symbiotic evolution and the second direct convergent evolution. The distinction between the two is due to the different nature of interaction between the groups involved in the two situations.

The expanding Roman Empire was a state-level society, and its expansion was the result of internal impetus at the elite level, and was carried out in the context of the ambitions and motivations of individuals within the ruling elite. The Celts were not a state level culture, and their elites were concerned as much with intra-cultural rivalry as extra-cultural threats. The two were not committed to necessarily separate ends, and were able to offer each other mutual benefits. Therefore they were able to coexist and evolve separately but together – hence, ‘symbiotic evolution’.

For the second example, the situation was markedly different. The Celtic expansion undoubtedly contained similar motives to the Roman one (personal status and wealth), and were thus likewise expression of internal values and social relationships. The Thracian culture they intruded upon was of an analogous social form and organisation, and they both shared a common Indo-European ancestry and similar histories involving contact with Greece. However, as opposed to the Romans, once the Celts had settled in an area they replaced the local elite, claiming the area as ‘sword-land’. They did not seem to have eliminated the general population, however, and one can imagine that life for the Thracian peasant was as little affected by the change in rulership as that for the British peasant by the Roman conquest.

Whereas Romans maintained their identity after the annex of Britain, the Scordisci became irrevocably altered through their settlement on the Triballi’s land. The reason for this is due to their different social structure and expression, or in other words the different kinds of problem which cultural interaction posed. Following conquest, the Roman Empire seems to have taken a minimal interest in the economy and politics of the conquered. The British, in turn, re-aligned themselves to the new situation, and demonstrated their status as members of the Roman Empire through appropriate social and economic discourse, but to what depth this ‘Romanness’ penetrated is debatable. For the Scordisci to have taken such an indifferent attitude to their conquered territory would have resulted in a less stable and potentially weaker hold upon it. The Celts had no empire (the title of Ellis’s book is ‘intentionally ‘mischievous’ (p.1)), no central rulership to sustain social conventions. In these conditions, a certain amount of assimilation into the existing social networks of the region would have to be made. That the Celtic and Thracian peoples were similar in many respects would have allowed this to occur fairly rapidly, and ideological propaganda – such as the creation of a common origin myth – legitimized the intrusive foreign presence by denying that any ‘foreignness’ existed. The Celtic reluctance to make written records (ibid.) fits into a social system which must maintain a fluid past to allow for future instability.

I hope that this short report has highlighted the usefulness of the application of an evolutionary model to specific archaeological questions.


Ellis, P.B. (1990). The Celtic Empire: The First Millennium of Celtic History c. 1000 BC – 51 AD Guild Publishing: London.

Harris, T.D. (1998). The Evolution of Cities and States (Unpublished Report). University of Bradford: Bradford.

Hingley, R. (1996). The ‘legacy’ of Rome: the rise, decline, and fall of the theory of Romanization. pp. 35-48 in J. Webster. and N. Cooper (eds). Roman Imperialism: Post-Colonial Perspectives Leicester Archaeology Monographs No. 3. University of Leicester: Leicester.

Kaul, F. (1991). The Gundestrup Cauldron – Thracian, Celtic or Both?, pp. 7-42 in Kaul, F., Marazov, H.B. and De Vries, N. (1991). Thracian Tales on the Gundestrup Cauldron, Najade Press: Amsterdam.

Kaul, F. (1995). The Gundestrup Cauldron Reconsidered, Acta Archaeologica 66, 1-38.

Millett, M. (1990). The Romanization of Britain: An essay in archaeological interpretation Cambridge University Press: Cambridge.

Popper, K.R. (1979 (Revised edition)). Objective Knowledge: An Evolutionary Approach, Oxford University Press: Oxford.

Rankin, D. (1996 (paperback)). Celts and the Classical World, Routledge: London.

Taylor, T. (1992). The Gundestrup Cauldron. Scientific American, March 1992.

Trigger, B. (1993). Early Civilizations: Ancient Egypt in Context, The American University: Cairo.

Webster, J. and N. Cooper (eds) (1996). Roman Imperialism: Post-Colonial Perspectives, Leicester Archaeology Monographs No. 3. University of Leicester: Leicester.

Wilson, E.O. (1993). The Diversity of Life. Allen Lane (The Penguin Press): London.

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