The evolution of multiple agricultures a

This view conceptually condenses cultural variation into a series of typological categories such as hunting-gathering and agriculture and fosters the view that evolutionary history consi

T HE E VOLUTON OF M ULTIPLE A GRICUTLURES

A Descent-Based Approach to the Study of Agricultural Origins and

Declaration

I hereby declare that the work presented in this thesis is the result of my own independent research, except where otherwise acknowledged in the bibliography This material has not been submitted either in whole or in part, for

a degree at this or any other university

………

Chris Lovell

2 Problems with the Study of Agricultural

Subsistence Categories and Agricultural Evolution 20

4 A Theory of Agricultural Evolution and Dispersal 69

The Cultural Dispersals of Agricultures 74

Abstract

The study of agricultural origins and dispersals is characterised by contradiction and confusion This confusion derives from a transformations-between-subsistence-categories view of evolutionary history This view conceptually condenses cultural variation into a series

of typological categories such as hunting-gathering and agriculture and fosters the view that evolutionary history consists of a single, universal pathway Meanwhile scholars find evidence of cultural variation and historical plurality, contradicting the expectations of the transformations-between-subsistence-categories approach In this thesis I argue for the complete abandonment of this approach in favour of a descent-based, Darwinian view of evolutionary history According to this view, agriculture is not ‘one thing’ Rather a

multiplicity of agricultures is said to exist Agricultural knowledge and practices are those that allow people to increase the availability of food Procurement is the act of getting food

Agricultures evolve and are inherited along lineages of descent These lineages can be used to classify agricultures into families or styles A phylogeny-based comparative method can be employed to support hypotheses about why and how specific agricultural practiced evolved and how and why they dispersed This approach generates a fundamentally different view of agricultural history and carries the study of agricultural evolution beyond the current confusion

Acknowledgements

First of all, I would like to thank my supervisor, Leonn Satterthwait for all the good advice and guidance he has given me over the course of writing this thesis Throughout the twists and turns that this project has taken, Leonn has supported my manoeuvres whilst offering critical advice More than anything I must thank Leonn for pushing me to write a thesis rather than a diatribe

I would also like to thank my parents, Janet and Dennis Lovell, who provided me with a place

to study, endless nurture and constant encouragement Without their help, this thesis could never have taken shape Throughout my life, they have encouraged me to pursue my passions and given freely their support No child could ask for more

Thanks must also go to Daniel Quinn for providing the foundational inspiration and point of view for this thesis Thankyou to Natalie Myers for her undying enthusiasm and support for all that I do, for her feedback and dialogues, and for helping to shape this way of thinking Thankyou to Mark Merrit for always providing a point of reference with his academic insights, creativity and enthusiasm and for providing feedback almost always at short or no notice Thankyou to Michael Edrich for all the dialogues and exchanges of the last several years that both he and I know contributed substantially to the shape of this thesis Thankyou

to my girlfriend Fiona Brown for always supporting me and for always being there, regardless

C HAPTER O NE

The transition from hunting-gathering to agriculture is often cited as a major benchmark in the cultural evolutionary history of our species Through several million years of evolution people are said to have subsisted by hunting and gathering Then, beginning about 10 or 12,000 years ago, and occurring in several parts of the world, people began to adopt an agricultural way of life As the agricultural way of life spread, the hunting-gathering way receded With agriculture everything commonly called ‘progress’—and a number of other things that appear degenerative—followed suit; or so the story goes In fact, scholars of agricultural origins and dispersals have been grappling with several serious conceptual and theoretical problems since

at least the late 1960s (Harris 1990:7-8) These problems include: (1) agreeing upon a definition of ‘agriculture’ and associated terms; (2) estimating the number of independent agricultural origins; (3) explaining why and how agriculture originated and spread; (4) understanding the significance of the multiple origins of and pathways toward agriculture; and (5) representing the diversity of agricultural and non-agricultural ways of life Given that scholars do not even agree as to what ‘agriculture’ is, it appears perfunctory that agriculture is given such significance in our ‘stories’ of cultural evolutionary history In this thesis I argue that the problems mentioned above derive from the application of non-Darwinian approaches

to problems of interpreting cultural diversity and understanding evolutionary history I argue that Darwinian theories and phylogenetic comparative methods may resolve many of these problems and present some tangible ways to move forward in the study of agricultural evolutionary history, albeit perhaps at the expense of this story Rather than the multiple

origins of agriculture, I suggest we study the evolution of multiple agricultures Rather than the study of agricultural dispersals I suggest we investigate the culture dispersal of

agricultures

1976, 1990, 1991; Freeman 1974; Ingold 1986a, 1998; Machalek and Martin 2004; Rindos

1985, 1986) From late nineteenth century ‘classical evolutionism’ (e.g Morgan 1978[1877]), through the ‘neoevolutionism’ of the 1950s and 1960s (e.g Sahlins 1960; Service 1962; White 1959), to recent theories of ‘social evolution’ (e.g Carneiro 2003; Hallpike 1986; Sanderson 1995) non-Darwinian approaches have focused upon the delineation of stages in the progression toward greater size, complexity and integration of cultural systems (Durham 1990:192)

Critics cite a number of problems with non-Darwinian approaches to cultural evolution First

of all, they are typological, meaning that cultures are divided into ‘types’ based upon their

similarity to an ‘ideal type’ constructed by the theorist (Feinman and Neitzel 1984:40-45) Common examples are Service’s (1962) ‘band’, ‘tribe’, ‘chiefdom’ and ‘state’ typologies

Typological approaches are generally considered to derive from philosophical essentialism

which is, roughly, the doctrine that the objects making up a class of things are imperfect derivations of an ideal type (Mayr 1976; 1991:35-47) In Plato’s well-worn cave allegory

‘real’ objects exist, but they are in the background, unseen People can only observe their

‘shadows’—imperfect projections of reality—upon the cave wall (Mayr 1991:40-41) According to essentialist philosophies, the variation between objects of a type is an illusion; a distortion of some underlying, unseen ‘reality’ (Mayr 1976:28) Critics note that, although actual cultures differ in detail from, say, Service’s ideal tribe, they are classified as ‘tribes’

because they possess the characteristics of the (unseen) ideal tribe Once actual, variable societies are grouped together under a single, typological category, such as this, a great deal

of cultural diversity simply disappears from view or consideration (Feinman and Neitzel 1984; Leonard and Jones 1987; Price 1985)

The second criticism is that these schemes are progressive, meaning that the types mentioned

above are ranked or ordered according to a series of developmental stages Evolutionary history, then, is said to proceed from stage to stage along directional, ‘linear’ or ‘multilinear’ axes, often said to improve or advance Dunnell (1988:184) and Hall (1988:138) note that the assumption of progress is problematic, first of all, because it leads to circularity in the interpretation of cultural diversity Cultural stages are ordered according to the assumption of progress, and then progress is interpreted from that order! Second, these approaches do not provide any mechanism or process by which evolution happens, and thus it remains a matter

of debate exactly why societies are impelled to progress from one stage to another (Alland 1970:30-51; Dunnell 1988:176-183) Third, these approach evoke the search for what Service (1968) calls ‘prime movers’ which are singular, deterministic, universally applicable forces said to impel cultures to evolve from stage to stage (e.g population pressure, warfare, climate change, etc.) Fourth, notions of progress are based upon value judgements about what is

‘better’ or ‘more advanced’ and are therefore subject to the biases of individual theorists (Dunnell 1988:183)

It is now well attested that ideas about historical progress from typological stage to stage were not pioneered by Darwin (Blute 1979; Dunnell 1980, 1988; Freeman 1974; Ingold 1986a,

1998, 2002; Rindos 1985) Although Darwin adhered to prevailing political views and

endorsed this view in The Descent of Man (1890[1874]) the theory of biological evolution he expounded in The Origin of Species (1999[1859]) was antithetical to this view (Ingold

1986a:1-73; 1998, 2002; Mayr 1976) Rather than ignoring the fact that individuals of a kind differ from one another, as in typological categorisation, Darwin suggested that variation is pivotal to the process of evolution Observing that individuals of the same species differ (however minutely) from one another (Darwin 1999[1859]:31-73), and that environmental conditions tend to change over time, Darwin argued that some individuals will have a better chance of surviving and reproducing in different environments than others Assuming that at least some of this variation is heritable (Darwin 1999[1859]:34-37), Darwin argued, natural (or any other process of) selection acting upon a variable population will produce evolutionary change (Darwin 1999[1859]:74-132)

A lesser-known consequence of Darwin’s theory is that typological thinking was replaced by

genealogical approaches of biological categorisation (Mayr 1976:27) Since individuals vary,

and since populations evolve over time, individuals cannot be considered imperfect derivations of some ‘ideal type’ and thus cannot be classed together on that basis Instead, organisms must be classed together because they are related via descent from common ancestors Mayr (1976:28) notes that this descent-based or genealogical view is diametrically opposed to essentialism, according to which ‘ideal types’ are real, whilst variation is illusory According to the genealogical view, categories are abstractions They do not actually exist The only thing that is real is variation Table 1.1 presents a summary of essentialist and nonessentialist positions regarding the nature of categories

Another consequence of Darwin’s theory was that progress could no longer be assumed to underlie the course of evolutionary history Rather, the course of evolutionary history is

revealed by following ‘lines of descent’ or genealogies—also called phylogenies—back in

time (Mayr 1976) As such, the idea that ‘progress happens’ is just a theory that, like any theory, must be tested against the prevailing evidence (Dunnell 1980:42; 1988:183-184)

Table 1.1 Essentialist versus non-essentialist positions regarding the nature of categories

(from Gelman 2003:12)

Intrinsic to individual category members Product of external forces

Stable over transformations Transient

Highly inductive potential Low inductive potential

Mutually exclusive traits Overlapping traits

Absolute category membership Graded category membership

Over the last 25 years theorists have developed a number of Darwinian approaches to understanding cultural diversity and evolutionary history (e.g Boyd and Richerson 1985; Cavalli-Sforza and Feldman 1981; Durham 1990, 1991; Irons 1979; Rindos 1985) Durham calls these approaches ‘evolutionary culture theory’ (ECT) ECT is “…in a word, a theory of cultural phylogeny…” says Durham (1990:189), meaning that “all human cultural systems are related by descent to a common ancestral culture” (Durham 1990:188) According to ECT, culture is a system of inheritance capable of evolution, albeit with important differences and connections to biological systems (Durham 1991:419-427) Central to ECT is the notion that cultures are related via descent to common ancestral cultures in branching, tree-like historical patterns called phylogenies (Durham 1990:190; 1992:331; Pagel and Mace 2004:278) Just as phylogenetic approaches replaced typological approaches to understanding patterns of biological diversity and evolutionary history (Mayr 1976), phylogenetic approaches are being offered in place of typological approaches to understanding cultural diversity and evolutionary histories (e.g Mace and Pagel 1994)

Problem

Agriculture has generally featured in non-Darwinian cultural evolutionary schemes as being both pivotal to historical progress and characteristic of particular stages in this progress (Morrison 1996:583-584; Pluciennik 1998, 2001; 2002:115-118) According to V Gordon Childe’s influential ‘neolithic revolution’ hypothesis (Childe 1936:74-117), the acquisition of agriculture “transformed the human economy… [giving] man control of his own food supply” (Childe 1936:74) For Childe, the acquisition of agriculture signalled the transition between the ‘Savagery’ and ‘Barbarism’ in Lewis Henry Morgan’s developmental scheme (1978[1877]:10-11) and between the mesolithic and neolithic in archaeological sequences, or

‘Ages’ as they were then known (Childe 1951:33) Childe was instrumental in popularising a non-Darwinian approach to the study of agricultural origins and dispersals, but was not the first, nor last, to take agriculture as defining a stage of cultural evolution and stimulating progressive change Ancient Greek and Roman philosophers pondered the ‘three ages of man’: hunting, herding and agriculture (Harris 1990:5); the classical evolutionist Lewis Henry Morgan (1978[1877]:19) thought that the progress of humans was “revealed… by their successive arts of subsistence” and that “the whole question of human supremacy on the earth depended” on “their skill in this direction”; and by the middle of the twentieth century, agriculture was often regarded as a legitimate stage of cultural evolution (Harris 1990:5-6) Following WWII Robert Braidwood lead the first formal scientific expeditions into agricultural origins Braidwood (1960:131) discusses the “agricultural revolution” which he says ushered in a new, progressive age of cultural evolution, distinct from the previous 500,000 to 1,000,000 years of “hunting and food-gathering” Today, authors are still found referring to transitions from hunting-gathering to agriculture as ushering in a new, progressive era of cultural evolution—although it is now commonly doubted that agriculture made things

‘better’ (e.g Arias 1999:404; Bar-Yosef 2004:S1; Brown 1999:89; Diamond 1997:85-191;

Gebauer and Price 1992a:1; Mannion 1999:38; Miller 1992:39; Price 2000b:1; Sanderson 1995:20-52; Smith 2001a:1324)

Pluciennik defines a ‘subsistence category’ as a typological category or evolutionary stage defined in terms of subsistence practices, such as ‘hunter-gatherers’, ‘agriculturalists’ or

‘farmers’ (Pluciennik 2001:741) Since at least the late 1960s concerns have been raised with approaches treating ‘agricultural origins’ as the transformation from one subsistence category

to another (Higgs and Jarman 1969, 1972) Theorists have since attempted to address these concerns in a number of ways, summarised in Table 1.1 These studies attempt to compensate for the fact that the typological, transformative approach obscures cultural diversity and historical variation by emphasising that cultures vary and histories are different Nonetheless these studies remain framed in terms of the ‘transformations-between-subsistence-categories’ view of cultural evolution (Pluciennik 2002:115) meaning that cultural variation is distilled into a series of subsistence categories and historical variation reduced to a single, simplified transformation from hunter-gatherer to farmer For example, despite widespread recognition that human cultural diversity is inadequately represented by subsistence categories, these categories remain central to such studies Meanwhile, scholars debate how best to encompass variation within these categories—‘hunting-gathering’ and ‘agricultural’ (Bird-David 1992b; Ingold 1986b; Yellen and Harpending 1972), ‘Neolithic’ and ‘Mesolithic’ (Prescott 1996; Zvelebil 1986b), and so on—whilst maintaining a typological approach

Table 1.1 Concerns about approaches that treat agriculture as being or defining a stage of

cultural evolution distinct from non-agriculture or hunting-gathering have been addressed in a number of ways

Conceptually bridging the perceived evolutionary and classificatory ‘gap’ between hunter-gatherers and agriculturalists (e.g Harris 1989, 1990; Smith 2001b)

Investigating the variety of transitional periods and processes between

hunting-gathering and agriculture (e.g Arias 1999; Bar-Yosef and Belfer-Cohen 1992;

Gould 1985; Gronenborn 1999; Kuijt and Goring-Morris 2002; Layton et al

1991; van Andel and Runnels 1995; Zvelebil and Rowley-Conwy 1984)

Providing local-scale analyses of archaeological data pertaining to agricultural

origins and dispersals (e.g Byrd 1992; Keeley 1992; Peltenburg et al 2000;

Price and Gebauer 1992; Taavitsainen et al 1998; van Andel and Runnels 1995)

Emphasising the diversity of hunting-gathering (e.g Binford 1980; Bird-David

1992b; Kelly 1995; Price and Brown 1985; Testart 1982; Williams and Hunn

1982; Woodburn 1980) and agricultural (e.g Boserup 1965; Johnson 2003; Leach 1999; Morrison 1994, 1996) societies and subsistence strategies

Formulating new definitions of agriculture and associated terms (reviewed in

Harris 1989:11-16; Smith 2001b:19-30)

Acknowledging the diversity of mesolithic and neolithic sites/cultures (e.g Gronenborn 1999; Kuijt and Goring-Morris 2002; Pinhasi and Pluciennik 2004;

Zeder 1994)

Recognising a multiplicity of pathways from hunting-gathering to agriculture

(e.g Fritz 1990; Hard and Roney 1998)

Applying Darwinian perspectives to the problem of explaining agricultural

origins and dispersals (e.g Hart 1999; Richerson et al 2001; Rindos 1980,

1984)

In chapter two I outline how confusion and contradiction of this sort characterises the study of agricultural origins and dispersals This situation exists, I argue, because scholars are prone to react against the non-Darwinian view of their forebears whilst maintaining the essentially same view A number of scholars have noted that similar conundrums arise whenever typological, transformative approaches are applied to problems of cultural evolution They suggest the application of a Darwinian approach according to which cultural variation is pivotal to the process of cultural evolution and cultural evolutionary histories are diverse (Blute 1979; Dunnell 1980, 1988; Feinman and Neitzel 1984:77-78; Leonard and Jones 1987:200-202; Yoffee 1993) In this thesis I argue that ECT, “a theory of cultural phylogeny”

(Durham 1990:189) can carry the study of agricultural origins and dispersals beyond the current conundrum

Phylogenetic approaches have yet to be widely applied to the study of agricultural origins and dispersals This is hardly surprising given that phylogenetic approaches are antithetical to the notion of transformational change between typological stages From an ECT point of view, the entire notion that agricultural origins and dispersals happen between “hunting-gathering” and “agriculture”—or any other subsistence categories—is highly dubious The very idea that

agriculture has origins is a product of typological thinking It derives from constructing two

purportedly exclusive categories, then solving the problem of continuity between them by creating an event (agricultural origins) to act as a conceptual bridge between one category (hunting-gathering) and another (agriculture) Although actual populations may not undergo sudden transformations over the course of evolutionary history (but see Eldredge and Gould 1972), essentialism presupposes that they do When moving from one category to another, populations presumably come to embody the ‘essence’ or ‘ideal type’ of the new category The simplest way to explain this is with transformational events (Ingold 1998:91-93) Some examples are: the neolithic revolution (Bar-Yosef 1998b; Childe 1936), modern human origins (Lahr and Foley 1998), and the origin of the state (Carneiro 1970) Although theorists may stress that these are processes, they are depicted as events

Applying ECT generates a fundamentally different view In this thesis I suggest that: (1) instead of investigating the ‘multiple origins’ of a singular, typological ‘agriculture’, we can

investigate the evolution of multiple agricultures; and (2) instead of tracing ‘agricultural dispersals’ we can trace the cultural dispersals of agricultures—(see Chapter Four) It is the

purpose of this thesis to explore these ideas As such, the specific research questions addressed are:

(1)

(2)

How is the confusion and contradiction currently exhibited by scholars of agricultural origins and dispersals related to a ‘transformations-between-subsistence-categories’ view of evolutionary history?

Can ECT carry the study of agricultural origins and dispersals beyond this conundrum?

Rationale

According to some recent interpretations of human evolutionary history, many of the crucial global issues confronting humankind—such as overpopulation, crises in health, ecological unsustainability, famine, undernourishment, social inequalities, loss of linguistic and cultural diversity, and diminishing agricultural returns (reviewed in UNDP 1992, 1996, 1999, 2003, 2004)—may have their origins in the deeper ‘prehistoric’ past and be linked, in particular, to the origins and spread of agriculture These studies and their claims are summarised in Table 1.2 In the early 1970s these sorts of studies began to emerge and many scholars subsequently altered their perception of agriculture Previously, agriculture was regarded a benchmark of evolutionary progress, heralding a new era of cultural refinement and advancement Now agriculture appears to be a kind of Pandora’s Box that, once opened, unleashed an assortment

of incredible and terrible consequences (e.g Diamond 1991:163-172; 1997:83-92; Harris 1977:9-30) Where the answer had once seemed obvious, scholars have since been inclined to wonder why agriculture evolved at all (Bronson 1975:64; Flannery 1972:307-308; Harris 1977:9-30; Lewis 1972:217; Reed 1977a)

Table 1.2 Studies are said to indicate that many of the crucial global issues confronting

humankind may have their origins in the deeper ‘prehistoric’ past and be linked to the origins and dispersals of agriculture

The health of Neolithic populations having adopted agriculture is poorer than

the health of Mesolithic and contemporary hunter-gatherers (Armelagos et al

1991; Cohen 1987, 1989; Cohen and Armelagos 1984; Eshed et al 2004a; Larsen 1995, 2003; Neel 1976; Pechenkina et al 2002; Truswell 1976)

Work-loads are lighter and working hours often shorter among hunter-gatherers

compared to agriculturalists (Eshed et al 2004a; Lee 1968, 1969, 1984;

McCarthy and McArthur 1960; Sahlins 1972; Winterhalder 1993; Woodburn 1968)

Productivity per unit energy/labour input diminishes with the adoption of agriculture and subsequent intensifications (Boserup 1965; Giampietro and Pimentel 1993)

Agricultural systems, although producing more food in the short-term, exhibit periodic productive instability due to ecosystem simplification and reliance upon few species, and hence are prone to crop failure and famine (Bogucki

1996b; Cox 1981; Lupton 1976; Matson et al 1997; Parrack 1981; Pimentel

1976; Rindos 1980; 1984:166-172, 254-285; Way 1977)

Neolithic sites indicate substantially increased rates of population growth with

the advent of agriculture (Eshed et al 2004b; Hassan 1973, 1975, 1980, 1981; Jackes et al 1997) and this deviates significantly from population trends over

the rest of human evolutionary history (Excoffier and Schneider 1999; Foley

1998; Harpending et al 1998; Hawks et al 2000; Rogers 1995; Sherry et al

1998)

The adoption of agriculture and subsequent increases in population density are linked to the emergence of institutionalised social inequalities (Hayden 1990, 1995b; Kuijt 2000; Kuijt and Goring-Morris 2002; Price 1995; Price and Feinman 1995)

Agricultural dispersals are linked to the diminishment of linguistic and cultural diversity (Bellwood 2001; Diamond 1997; Diamond and Bellwood 2003; Nettle

1998; Nettle and Romaine 2000:99-125; Renfrew 1987, 1996)

Agriculture is linked to ecological unsustainability (Bogucki 1996b; Meritt

2001; Rollefson and Kohler-Rollefson 1992; Rollefson et al 1992)

However, given that no single, satisfactory definition of agriculture even exists (Harris 1996b:3), saying that ‘agriculture’ is linked to these problems does not convey a great deal of information When asked: “What is it about agriculture that causes, or is caused by, these problems?” the argument can easily slip into a semantic discussion about what agriculture is

By all indications, there may be no end to this discussion and thus no answer to this question

When agriculture is defined, definitions tend to be very open, since a great deal of variability

in agricultural ways of life must be encompassed Again, this means that it is difficult to say

what, exactly, it is about ‘agriculture’ that caused (or was caused by) these problems Furthermore, we might find that in one part of the world ‘agriculture’ lead to many (or all) of these problems, whilst in another it lead only to some Typological approaches do not lend themselves to explaining such differences because the fact that ‘agriculture’ differs in different parts of the world is obscured

However, if the emergence of these problems is linked to the spread of a culture (or cultures) practicing a particular agriculture (or agricultures) in particular parts of the world the association is potentially far more informative The insight that different populations adopting different ‘agricultures’ exhibited different trends and experienced different historical trajectories, can be put to use It might be found, for instance, that agricultural evolution in Southwest Asia, and subsequent cultural dispersals across the Middle East, Europe, Asia and

North Africa, were associated with all of these problems It might then be found that agricultural evolution and dispersal in New Guinea was associated with only some of these

problems The differences between these agricultures and associated historical trends have the potential to refine the link between particular agricultures and the emergence of certain historical trends and the problems associated with them Phylogeny-based comparative methods were developed to identify independent instances of cultural evolution in order to attribute significance to correlated patterns of cross-cultural similarity and cross-cultural difference (Mace and Pagel 1994) My suggestion is that this method can be applied to patterns of agricultural diversity to shed light upon the origins of the global issues currently confronting humankind

One important area of research to which such a method could be fruitfully applied is the study

of unsustainability, its origins and evolutionary history Although very much in its infancy

(see Betancourt and Van Devender 1981; Bogucki 1996b; Catton 1993; Fall et al 2002; Fritz

1995; Hedrick-Wong 1998; Hill 2004; Kohler 1992; Meritt 2001; Quinn 1992, 1996;

Rollefson and Kohler-Rollefson 1989, 1992; Rollefson et al 1992; Tainter 1995), tracing the

origins of unsustainability into the deeper historical past is, potentially, an important field of research Leeuw and Redman (2002) argue that only through the study of anthropology and archaeology can significant contributions be made to this field Previous work in this area suggests that unsustainability is differentially associated with different cultures and, particularly, with different agricultures (Meritt 2001:77-87) According to this view, the origins of unsustainability are both cultural, and agricultural, since both are intertwined (Meritt 2001; Quinn 1992, 1996) However, a method for investigating these ideas has not yet been suggested This study is important because it provides a preliminary overview and appraisal of ECT and phylogeny-based comparative methods and their applicability to the problem of understanding agricultural evolution and dispersals This approach may also shed light upon the origins of the global issues currently confronting humankind, including those associated with unsustainability

Overview of Thesis

In Chapter Two I address the first question: How is the stalemate currently experienced by scholars of agricultural origins and dispersals related to a ‘transformations-between-subsistence-categories’ view of evolutionary history? Firstly, I give a brief sketch of the historical emergence of this view I then outline how this approach is hindered by evidence of cultural and historical diversity and how scholars have dealt with this hindrance I show that although scholars have confronted the shortcomings of the typological, transformative approach, a significantly different view of cultural evolution has not been applied As such, I argue, studies of agricultural origins and dispersals are contradictory and confusing The following three chapters are dedicated to the second question: Can ECT carry the study of agricultural origins and dispersals beyond this conundrum? In Chapter Three I outline the theoretical and methodological approaches adopted in this thesis—ECT and its companion

methodology, comparative phylogenetics In Chapter Four I explore the ‘evolution of multiple agricultures’ and the ‘cultural dispersals of agricultures’ through the lens of ECT In Chapter Five I discuss the consequences and ramifications of this approach and suggest directions for future research

C HAPTER T WO

In this chapter I address the question: How is the confusion and contradiction currently exhibited by scholars of agricultural origins and dispersals related to a transformations-between-subsistence-categories view of evolutionary history? In the previous chapter I claimed that scholars currently emphasise that human cultures are diverse and that cultural histories are different, but that this is compensation for a transformations-between-subsistence-categories view of cultural evolution In this chapter I substantiate this claim, arguing that this conundrum derives from the application of a typological, transformative view of evolutionary history This approach distils cultural variation into a series of ‘ideal types’ and defines historical change as occurring between evolutionary stages In the case of agricultural origins and dispersals, subsistence categories (e.g hunting-gathering and agriculture) are depicted and agricultural evolution is perceived as the transformation from one stage of subsistence (hunting-gathering) to another (agriculture) I argue that, no matter how categories are defined, nor how many subcategories are outlined, cultural variation is always under-represented Furthermore, the ‘fact’ of variation undercuts the utility of this approach and contributes directly to the confusion The argument set out here justifies the abandonment of this approach in favour of one that can encompass, and make sense of, cultural diversity and historical differences Thus, I justify looking toward a Darwinian view

of cultural evolution in chapter three

Historical Background

Interest in the origins of agriculture has a long Western intellectual history For instance, ancient Greek and Roman philosophers outlined the ‘three stages of man’: hunting, herding and agriculture (Harris 1990:5) Scottish Enlightenment thinkers of the mid-eighteenth century, such as Sir John Dalrymple and Adam Smith, charted historical progress through sequences of subsistence categories or stages (Barnard 2004:34-41; Pluciennik 2001:741-742) Pluciennik (2001) notes that over the following 250 years the use of subsistence

categories to chart historical progress waxed and waned in popularity As the classical evolutionists (e.g Morgan 1978[1877]; Tylor 1881) revived the use of subsistence categories

in the late nineteenth century, a modern interest in the origins of agriculture was developing (e.g Darwin 1868:326-327; de Candolle 1884; Roth 1887; Tylor 1881:214) Geological and palaeontological discoveries had lead, gradually, to the scientific acceptance of geological timeframes and, eventually, to an acceptance of human antiquity contra literal Biblical interpretations (for reviews, see Daniel 1976; Grayson 1983; Leakey and Goodall 1969; Sackett 2000) At the same time, ‘hunting and gathering’ became cemented into place as the bottom rung of an evolutionary ladder leading upwards to agriculture and beyond (Golson 1977:6) As Buckland explained in 1878:

Archaeological records prove that man in his earliest condition was no

cultivator of the soil, no keeper of herds and flocks, but a wild and savage

hunter, flitting from place to place continually in pursuit of his prey…

(Buckland 1878:2)

Thus, the study of agricultural origins, as we know it, emerged within the context of a particular view of human evolutionary history—as sequentially progressing from one subsistence category to another—and has largely remained predicated upon this view ever since (Pluciennik 2002:115-117)

Problems with this approach were identified quickly, most famously by Franz Boas (1896), who criticised the use of the ‘comparative method’—that is, the use of typological categories

to interpret present-day patterns of cultural diversity and, vice versa, the use of present-day cultural diversity to substantiate typological schemes Different cultures have different historical lineages, Boas argued They cannot simply be slotted into some particular stage of some purportedly universal sequence of historical development Nevertheless—and despite anthropology moving generally away from ‘evolutionism’ during the twentieth century (for reviews, see Carneiro 2003:75-98; Sanderson 1990:36-49)—discourse on agricultural origins

and dispersals remained couched in terms of transitions between subsistence categories and,

as such, retained the logic of late nineteenth century comparative methods (see Harris 1968:150-179; Pluciennik 2001:753; 2002:115-117)

Toward the end of the nineteenth century, archaeologists and anthropologists had come to differ in their bases for classifying stages Archaeologists had recognised evidence of farming, but had preferred a technological basis for classification—hence delineating the Stone (Palaeolithic, Mesolithic and Neolithic), Bronze and Iron Ages—whereas anthropologists had preferred the use of cultural markers of various kinds (e.g the advent of writing, centralised political authority, etc.) and subsistence practices (Pluciennik 2001:744-746) Pluciennik (2001:748) notes that by 1920 it was the conventional wisdom that Neolithic sites were characterised by agriculture, as well as by technological markers such as pottery and ground

stone tools When Childe (1951:22) suggested in 1925 in The Dawn of European Civilization

that “food-production should… define the transition from Savagery to Barbarism, and so far

to allow Barbarism and Neolithic to coincide”, he was not suggesting anything new, as he admits (Childe 1951:32) Rather:

…the authority of Childe, and interest in the ‘origins of agriculture’, soon

assured the archaeological success of definitions of an ‘Old World’ Neolithic

predicated on the presence of farming (Pluciennik 2001:749)

When, following World War II, Robert Braidwood led the first scientific expeditions to Iraq

to investigate a Near Eastern origin of agriculture he did so with a Childean view, taking agriculture as an indication that a new stage of cultural evolution had been entered:

It is now usual to view the appearance of the earliest village communities as

an aspect of the revolution which marked the transition from the

food-gathering to the food-production stages… (Braidwood and Braidwood

1953:279)

Higgs and Jarman (1969; 1972) were among the first to critically analyse this assumption, citing (among other things) the weakness of typological classification:

The … assumption that societies are agricultural or non-agricultural, or that

animals are wild or domestic, rests on a classification of the data into two

groups which it may be convenient to form, but which may not in fact have

any reality… When such an artificial taxonomic line is created, subsequently

it may be used as if it were an absolute division, a usage which obscures the

fact that in reality there is an important and steady graduation from one class

to another (Higgs and Jarman 1972:32)

Nonetheless, studies of agricultural origins and dispersals, couched in terms of transitions between subsistence categories, have been highly influential throughout the 1970s (e.g Cohen 1977; Higgs 1972; Reed 1977b; Struever 1971; Ucko and Dimbleby 1969), 1980s (e.g Harris and Hillman 1989; Rindos 1984; Zohary and Hopf 1994[1988]; Zvelebil 1986a), 1990s (e.g

Anderson 1999; Cowan et al 1992; Edmonds and Richards 1998; Gebauer and Price 1992b;

Harris 1996c; Price and Gebauer 1995) and continue to be influential in the twenty-first century (e.g Bellwood 2005; Kuijt 2000; Price 2000a)

Subsistence Categories and Agricultural Evolution

A consequence of the transformations-between-subsistence-categories approach to agricultural evolution is the need to define a singular, typological ‘agriculture’ Since typological classification involves grouping objects together into discrete categories based upon their similarity to an ‘ideal type’ constructed by the theorist, the criteria by which particular societies are judged to be agricultural, or not, must be discovered—see Table 1.1 According to essentialist philosophies everything under the category ‘agriculture’ is essentially the same thing (embodying the same underlying agricultural essence or ideal type), whilst everything under the category ‘hunting-gathering’ is essentially another thing (embodying the same underlying hunting-gathering essence or ideal type), and these essences

are maintained despite the fact that actual societies of each type vary (see Figure 2.1.)

(a) ‘Thin line’

Figure 2.1 (a) The transformations-between-subsistence-categories approach to

understanding human evolutionary history ‘Ideal types’ or ‘essences’ are the focus of continuous variation Categories are separated by ‘thin lines’ and linked via transformations This is fundamentally the same logic that informed late nineteenth century comparative methods (see Harris 1968:150-179) (b) ‘Side view’ showing projections of ideal types onto actual variable societies Levels of categorisation—from general types to specific societies—are also depicted Dashed lines show how projections funnel variation into ‘ideal types’ Grey lines show how ideal types are conceptually maintained whilst being projected through sub-categories onto actual societies Scholars generalise from actual societies about transformations between ideal types (i.e the ‘comparative method’) to find a single explanation for the origins and dispersals of agriculture

Pluciennik notes:

…implicit in this view is the assumption that there is some essential

difference, beyond that of subsistence, between farming and non-farming

societies—whatever the variability within either (Pluciennik 1998:69)

However, several lines of evidence work against the formulation of a singular, typological definition of agriculture

Following the publication of Man the Hunter (Lee and DeVore 1968) variation amongst

hunter-gatherers (past and present) became a hot topic in anthropology With evidence of subsistence (and cultural) variation amongst hunting-gathering societies scholars reacted initially against Steward’s patrilineal (1955:122-150) and Service’s patrilocal (1962:59-109) band typologies, then against Sahlin’s (1972:1-39) ‘original affluent society’ (OAS) model as being simplistic and over-generalised (see Altman 1984; Barnard 1983; Bird-David 1992a; Hawkes and O'Connell 1981; Rowley-Conwy 2001) In response, numerous models stressing variation were developed incorporating a swathe of new sub-categories—‘simple’ and

‘complex’ (Keeley 1988; Price and Brown 1985), ‘foragers’ and ‘collectors’ (Binford 1980),

‘immediate return’ and ‘delayed return’ (Woodburn 1980), and others (e.g Arnold 1996; Kelly 1992; Testart 1982; Watanabe 1968)—but none gained widespread acceptance (for reviews see Barnard 1983; Kelly 1995:10-37; Zvelebil 1998:5-11) At the same time the general utility of the category, both as a generalised ‘cultural type’ and as a ‘mode of production’, was questioned (Barnard 1983; Hall 1988; Kelly 1995:33-35) Meanwhile, others maintained that amidst the heterogeneity a core set of traits defined hunting-gathering, but held differing opinions as to what these traits were (Bettinger 1991; Bird-David 1990, 1992b; Brody 2001; Ingold 2000:61-76; Kent 1992; Lee and Daly 1999:3) The result is that there is currently no agreement about what it means to be a ‘hunter-gatherer’, or how to represent variation The ‘essence’ of hunting-gathering has proven difficult to discover, and variation is

the reason (Kelly 1995) However, the perceived need to discover this essence derives from the application of typological approach to classification

Further compromising the efficacy of typological subsistence categories is evidence that hunter-gatherers often do things that are agricultural—or ‘protoagricultural’ according to Keeley (1995)—whilst farmers often hunt and gather For example, ethnographic, ethnohistorical and archaeological records indicate that people classified as hunter-gatherers

‘manage’ their food resources by employing what appear to be agricultural techniques—see Table 2.1 Likewise, peoples classified as being agricultural, horticultural, Neolithic or simply farmers hunt ‘wild’ animals and gather ‘wild’ plant materials (Alcorn 1981; Chagnon 1983; Constantini 1989; Hall 1988; Harlan 1989; Kent 1989; Posey 1985; Rappaport 1984; Zeder 1994) What this means is the practice of hunting-gathering and agriculture overlap significantly in many societies This observation works against the notion that hunting-gathering and agriculture are discrete categories in general, and against the idea that societies can be classified on the basis of subsistence traits in particular The ‘thin line’ is actually

‘blurred’—see Figure 2.2 However, the perception of a thin line derives from a typological,

transformative view of cultural evolution

Table 2.1 Ethnographic, ethnohistorical and archaeological records indicate that

hunter-gatherers ‘manage’ their food resources, employing agricultural or ‘protoagricultural’ techniques

Harvesting, burning and then broadcasting seeds over fields (Keeley 1995; Shipek 1989:162)

Promoting hybrid plant varieties (Shipek 1989:163)

Planting and interplanting seeds and vegetative cuttings (Hynes and Chase 1982:40-41; Shipek 1989:163-164)

Protecting seedlings (Hynes and Chase 1982:40)

Strategically employing fire to increase the production of particular food resources (Beaton 1982; Jones 1969; Latz 1995; Lewis 1982)

Observing well-defined usage rights and seasonal schedules of plant exploitation (Goodale 1982; Hallam 1989; Richardson 1982)

Maintain canal systems for hydraulic management and harvesting of eels (Lourandos 1980)

Labouring in the fields of farming neighbours and also opportunistically gardening and raising livestock (Kent 1992; Layton 2001)

Figure 2.2 Studies of agricultural origins and dispersals are contradictory and confusing

This conundrum results from the application of a typological, transformative view of cultural evolution Where the approach generates an expectation of discrete categories, scholars find that in actual societies hunting-gathering and agriculture overlap Rather than discovering the essence of ‘agriculture’ and the essence of ‘hunting-gathering’ scholars discover variation As such it remains unclear what defines agriculture and hunting-gathering; what differentiates hunting-gathering and agriculture; how variable hunting-gathering and agriculture are; and what transformations from hunting-gathering to agriculture entail

Societies classed as agricultural are also highly variable (Scott 1998:264-286) Scholars agree that agriculture emerged independently several times with notably different results—for example, in Mesoamerica (e.g MacNeish and Eubanks 2000; Piperno and Flannery 2001), Eastern North America (Fritz 1990; O'Brien 1987; Smith 1989, 1995), the Andes (Bellwood 2005:159-165), New Guinea (e.g Golson 1989; Golson and Gardner 1990), at least two areas

of China (e.g Higham and Lu 1998; Shelach 2000), Southwest Asia (e.g Bar-Yosef and Belfer-Cohen 1989; Bar-Yosef and Meadow 1995; Bar-Yosef and Valla 1990; Byrd 1994; Harris 1998; Kuijt and Goring-Morris 2002); and perhaps parts of Africa (e.g Bellwood 2005:97-110; Smith 1992; Sowunmi 1985)—and then dispersed into different parts of the world, diversifying and often intensifying over time (e.g Bellwood 1985, 2005; Bogucki 1996a; Byrd 1992; Edmonds and Richards 1998; Gronenborn 1999; Higham 1995; Kirch and

Green 1987; Taavitsainen et al 1998) The ‘industrial agriculture’ of present-day Illinois, in

the American Midwest (Barlett 1987), is certainly not the same as the ‘slash-and-burn horticulture’ among the Yanomamö of Venezuela and Brazil (Chagnon 1983)

A myriad of sub-categories have been defined in an attempt to encompass this variation Braidwood proposed ‘incipient agriculture’ and the ‘village-farming community’ as stages in the process of agricultural origins [revolution] (Braidwood 1958:1428), whilst other common categories include: ‘swidden farmers’, ‘horticulturalists’ and ‘gardeners’ (for critiques see Fritz 1990:389-391; Leach 1997; Smith 2001b:21-24) Boserup (1965:15-16) argued for five

‘types of land use’, each increasing in intensity and purported to occur in historical sequence: (1) forest-fallow cultivation; (2) bush-fallow cultivation; (3) short-fallow cultivation; (4) annual cropping; and (5) multi-cropping (for critiques see Johnson 2003; Leach 1999; Morrison 1994, 1996) Recent critiques focus on semantic inconsistency (e.g Leach 1997; Smith 2001b) and the inadequate representation of variation in actual societies and their historical pathways (e.g Johnson 2003; Leach 1999; Morrison 1994, 1996) However, the

need to define sub-categories and the perception that historical change occurs during transformations between types derives from a typological, transformative view of evolutionary history

Scholars have attempted to identify the core traits that distinguish agricultural societies from

hunter-gatherers Definitions of plant-based systems have generally focused on cultivation and domestication However, cultivation is inconsistently defined, largely due to the diversity

of practices which may be said to constitute cultivation (Smith 2001b:19-21) Some of the suggested criteria are: protection, sowing, planting, tending, land clearance, weeding, pruning, irrigation, drainage, seed selection, maintenance of soil fertility, exclusion of predators, soil tillage and harvesting (Cohen 1977:18-27; Ford 1985:3-6; Harris 1989:16-22; Rindos 1984:101-112; Scott 1998:265; Smith 2001b:19-21) Domestication, meanwhile, has been defined in ways ranging from the cultural/symbolic (e.g Chase 1989; Hodder 1990) to the population-genetic (e.g Ladizinsky 1998) However, domestication has long been recognised

as an evolutionary process (Darwin 1868, 1999[1859]; de Candolle 1884; Vavilov 1951) and

is widely defined along the lines of “genetic changes within a food species’ population through interactions with humans (i.e coevolution) such that the species’ population becomes reliant upon the human population for survival (i.e mutualistic symbiosis)” (Blumler and Byrne 1991:24; Garrard 1999:68; Harris 1998:5; Hillman and Davies 1990b:158; Ladizinsky

1998:7; Reed 1977c:18-19; Rindos 1980:753-757; 1984:138-189; Smith 2001b:14-17; Wilke

et al 1972:204-205) Furthermore, the presence of particular morphological markers appears

to signal the presence of agricultural forms of behaviour which appear to have exerted selective pressures upon populations causing them to evolve—to become domesticated

(Butler 1989; Diamond 2002; Kislev 1999; Ladizinsky 1989; Lev-Yadun et al 2000;

Mannion 1999; Miller 1992; Zohary 1996) For some seed plants a characteristic swathe of traits—dubbed the ‘domestication syndrome’ (e.g increased seed size, increased size or

number of inflorescences, reduction in seed dormancy, a non-shattering rachis, etc.)—

emerges with particular cultivation, harvesting and planting practices (Harlan et al

1973:314) Studies involving ‘wild-type’ wheats and barley indicate that domestication syndromes can evolve within 200 years, or even within as few as 20-30 years, of being cultivated, harvested and planted without any sort of conscious selective process (Hillman and Davies 1990a, 1990b, 1999) A similar swathe of characteristics has been identified for animals (Leach 2003:349)

However, the proposition that domesticated species cannot survive without humans is problematic since many domesticates are known to survive in the absence of human care For example, ‘feral’ animals such as cattle, pigs, horses, donkeys, camels, dogs, cats and rabbits challenge the idea of a ‘one way’ evolutionary journey into domestication (O'Rourke 2000:148) Moreover, evidence suggests that those coevolutionary changes mentioned in the above definition of domestication compose only a subset of the coevolutionary changes that have happened as humans have interacted with other species in general—which, in turn, are only a subset of the coevolutionary changes that have happened as a result of species in general interacting with one another For example, evolutionary change can take place when people (and other animals) show preferences for particular characteristics in gathering plant materials and hunting animals Such plants and animals become subject to human-induced selective pressures (Alcorn 1981; Ford 1985; Hynes and Chase 1982; Kunzar 2001) Selection can also take place when people act as dispersal agents for plants, for example, dispersing seeds around camp sites and along walking tracks (Anderson 1952, 1955; Rindos 1984:154-158; Yen 1989:60-61) The use of fire management techniques to affect the diversity, distribution and production of resources by indigenous North American and Australian peoples may exert selective pressures causing species to undergo evolutionary change (Forni 1984; Lewis 1972, 1982; Yen 1989:58-62) Furthermore, human populations have undergone

genetic changes whilst interacting with plants, animals and other organisms For example, genes encoding for sickle-cell anaemia have spread through populations interacting with malaria carrying mosquitos, and genes for prolonged lactose absorption in adults have spread through populations interacting with cows (e.g Durham 1991:CH.3, CH.5; Feldman and Cavalli-Sforza 1989; Simoons 1981; Stinson 1992) Leach calls these processes ‘human domestication’ (Leach 2003)

In light of this, a more inclusive (but in some ways narrower) view of domestication is suggested by Rindos (1980; 1984) and others (Higgs and Jarman 1969, 1972; Kunzar 2001; O'Brien 1987; Pearsall 1995; Shigeta 1996), who equate domestication with the coevolution

of particular symbiotic mutualisms, involving humans or not According to Rindos (1984:143): “Domestication is a coevolutionary process in which any given taxon diverges from an original gene pool and establishes a symbiotic protection and dispersal relationship with the animal feeding on it.” Thus agriculture becomes “an integrated set of animal behaviours that affect the environment inhabited by domesticated plants throughout the whole life cycle of those plants” (Rindos 1984:256) Rindos outlines a series of mutualistic interactions between animals and plants that involve coevolution and may constitute domestication and agriculture—such as beetles, wasps, ants and termites that protect, disperse and feed upon fungi; birds, bats and insects that feed upon fruit and nectaries, dispersing seeds and pollen in the process (Rindos 1984:99-120) Extending Rindos’ view beyond ‘animals’ interacting with ‘plants’, other coevolved mutualistic relationships may constitute domestication and agriculture—plants feed coevolved ‘mycorrhizal’ fungi which protect their

roots whilst increasing water and nutrient uptake (Raven et al 1999:340-344); lichens consist

of a fungus that protects, disperses and feeds upon coevolved photosynthetic algae (Raven et

al 1999:334-340); and so on

Regardless of what definition of domestication—or of agriculture—one accepts, it is clear that genetic changes due to agricultural interactions between humans and their favoured food

species are not different in kind from the coevolutionary processes experienced by all living

populations, over time, as a consequence of ‘living together’, or symbioses (Higgs and Jarman

1969, 1972; Reed 1977c; Rindos 1980, 1984, 1989) Rather than delineating the ‘essence’ of what it means to be agricultural, domestication evidences the continuities between agricultural and non-agricultural human (and indeed non-human) lifestyles As such, even in the narrowest sense, domestication does not delineate a point of essential difference or separation between agriculture and hunting-gathering However, the perception that domestication (or

something) should define the border between hunting-gathering and agriculture derives the

typological, transformative view

In the introduction to a recent anthology on agricultural origins and dispersals (Harris 1996c) Harris notes:

The published literature on “agricultural origins” is characterised by a

confusing multiplicity of terms for the conceptual categories that define our

discourse There is little agreement about what precisely is meant by such

terms as agriculture, horticulture, cultivation, domestication and husbandry

This semantic confusion militates against clear thinking about the phenomena

we investigate, leads to misunderstanding, and can provoke unnecessary

disputes over interpretation of the evidence (Harris 1996a:3)

For example, although scholars agree that agriculture emerged independently several times in several different parts of the world, there is no consensus about the number of times Given that scholars do not agree what agriculture is, it seems logical that scholars will not agree on the number of times it emerged! What looks like agriculture to one scholar might not look like agriculture to another What Harris calls a lack of clear thinking I call a confusing and contradictory conundrum (summarised in Figure 2.2.)

In this section I have shown that this conundrum results from the application of a typological, transformative view of cultural evolution Where scholars expect to find discrete categories (and sub-categories) we find hunting-gathering and agriculture overlap Where scholars expect to discover the essence of ‘agriculture’ and the essence of ‘hunting-gathering’ we discover variation As such, it remains unclear what defines agriculture and hunting-gathering; what differentiates hunting-gathering and agriculture; how variable hunting-gathering and agriculture are; and how hunter-gatherers transform into agriculturalists Nonetheless, the study of agricultural origins and dispersals goes on, largely predicated upon

a transformations-between-subsistence-categories view of cultural evolution

In response to these problems a number of approaches have been developed that emphasise continuity and variation Among them is Harris’s “classificatory and evolutionary model of plant food-yielding systems” (Harris 1990:39) (see Figure 2.3.), Smith’s “conceptual-developmental map of the middle ground between hunting-gathering and agriculture” (Smith 2001b:15) (see Figure 2.4.), Ford’s “stages and methods of plant food production” (Ford 1985:2) (see Figure 2.5.) and Zvelebil and Rowley-Conwy’s “three-stage availability model for the transition to farming” (Zvelebil 1996:325; see also Zvelebil and Rowley-Conwy 1984) (see Figure 2.6.) All four approaches follow a similar template (outlined in Figure 2.7.), one which maintains a transformations-between-subsistence-categories view of evolutionary history Each attempts to reduce subsistence variation into types and evolutionary history into

a sequence of stages despite the fact that actual cultures and their evolutionary histories vary substantially (see Figures 2.3 to 2.7.)

Replacement planting Land clearance Cultivation of Transplanting Soil tillage Domesticated

crops (cultivars)

Protective tending Weeding

Plant-exploitative

activities

Harvesting Storage Drainage/Irrigation

Figure 2.3 “A classificatory and evolutionary model of plant-food yielding systems… The

Roman numerals indicate postulated thresholds in the input of human energy” (Harris 1990:39) Harris provides a solution to the problem of representing cultural diversity and historical continuity in terms of transformations-between-subsistence-categories Harris has since modified this scheme, both widening the span of domestication and emphasising the gradual nature of increasing reliance on domesticates and decreasing reliance on ‘wild plants’ (Harris 1996a:445) A similar model of animal exploitation was also developed (Harris 1996a:449) This depiction “greatly oversimplifies the diverse ways in which humans have exploited plants and animals”, says Harris (1996b:4), adding the proviso that these models do not imply “…any inevitable evolutionary progression from one system of exploitation to another…” or “…that all domesticates have followed an essentially similar pathway to domestication” (Harris 1996b:4) Nonetheless, Harris delineates a series of ‘ideal types’ defined in terms of core traits; thresholds are posited, corresponding to ‘blurry lines’ between types (redrawn from Harris 1990:39)

Figure 2.4 “A conceptual and developmental map of the middle ground between

hunting-gathering and agriculture” (Smith 2001b:15) Smith provides a solution to the problem of subsistence variation within and continuity between subsistence categories in terms of a developmental ‘landscape’ cut by a “massive and sinuous mountain range” that is, for Smith, domestication (Smith 2001b:14) Agriculture and hunting-gathering are conceptually separated by a ‘middle ground’ Smith calls ‘low level food production’ through which the

‘mountain range’ courses A continuum of increasing reliance upon domesticates lies between the ‘mountain range’ and the ‘countryside’ which eventually blends into agriculture by degrees: “with isobars of 30, 40, and 50% contribution of domesticates to annual caloric budgets” (Smith 2001b:17) Low level food production is further broken into two sub-categories: “low-level food production economies without domesticates” (Smith 2001b:27-33) and “nonagricultural societies with domesticates” (Smith 2001b:17-26) Smith emphasises that the middle ground is inhabited by “diverse, vibrant and successful human societies” and that: “Quite diverse developmental pathways in all likelihood existed in different regions” (Smith 2001b:24) Nonetheless Smith’s scheme simplifies subsistence variation and evolutionary history (copied directly from Smith 2001b:15)

Figure 2.5 “The stages and methods of plant food production” (Ford 1985:2) Ford provides

a solution to variation within and continuity between subsistence categories The dashed line, leading into a full-line, then a thickening wedge, represents increasing degrees of genetic changes to species populations due to interactions with humans (Ford 1985:3) Although admitting that: “Because the genetic changes leading to true domestication are cumulative, it

is difficult to identify an absolute distinction between wild and domesticated plants” (Ford 1985:6) Ford maintains that domestication defines “the final stage of plant food production” (Ford 1985:6)

Figure 2.6 “The three-stage availability model of the transition to farming” (Zvelebil

1996:325) originally developed by Zvelebil and Rowley-Conwy (1984) The model is intended to depict the process whereby hunter-gatherers turn into farmers during agricultural dispersals and is compatible with both ‘cultural diffusion’ and ‘demic diffusion’ models as discussed later in this chapter The model focuses upon a particular archaeological area, tracking the transition in terms of the proportion of domesticates and cultigens in archaeological remains The model acknowledges variability at both the beginning (i.e Mesolithic) and end (i.e Neolithic) points of this process, but is explicitly not about why agriculture dispersed (Zvelebil 1986b:15) Although stressing variability, the model depicts

societies passing through “essentially the same sequence of events” (Zvelebil and

Rowley-Conwy 1984:123 empasis in original) during transitions to agriculture (copied directly from Zvelebil 1996:325)