«By Nathan B. Goodale A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE ...»
Viability of Human Osteological Data While both genetic markers of migration and demographic inquiry into cemetery data have provided significant information relevant to understanding the NDT in several regions of the world, all are limited by the following: 1) in many areas of the world cemeteries are not common and/or human skeletons are rare; 2) the
impossible to obtain in North America by the Native American Graves and Repatriation Act (enacted into federal US law in 1990); and 3) the expertise and precision to conduct the osteological analysis needed requires a highly trained specialist.
Although our sociopolitical climate is partly to blame for some of these issues of availability of human osteological data – rather than any fault on the part of Bocquet-Appel and his colleagues – the lack of standardization and restricted availability of these data limits the replicability of their approach. In addition, due to the paucity of data for both hunter-gatherers and farmers throughout the demographic transition in many of their case studies, I remain skeptical of the actual signals in several instances, ultimately drawing some questions regarding the methodological techniques and the amount of data available to detect the patterns of the NDT.
In light of these issues, I suggest that other techniques and datasets for
paleoanthropological data from cemeteries. I do not mean to suggest that these studies I have just reviewed are unimportant, rather I seek to strengthen and extend them by developing additional data sources that should, if the NDT model is correct, yield complementary results.
Models built with extensive archaeological data including the frequency of sites occupied, the number of radiocarbon dates, the depth of deposits, or site sizes all encompass the third data set which Bocquet-Appel (2002:637) suggests may lend information to detecting an NDT. This entails utilizing several variables that are signatures of population size (a detailed review can be found in Hassan 1981). While this approach has been suggested as viable, it has not been thoroughly tested for the NDT. In this study I will present research indicating that construction of population growth rate models based on attainable archaeological data is an effective method of investigating and modeling the NDT.
There have been a number of methods proposed to determine human population sizes utilizing archaeological assemblages (for detailed reviews see Chamberlain 2006; Hassan 1981). It is not the goal here to cover all of the means by which archaeologists have attempted to reconstruct past population densities as well as population growth rates. A quick summary would include the use of ecological modeling (Nickles and Sappington 1999), artifact densities (Turner and Lofgren 1966), estimated population totals for ceramics (Kohler 1978), annual dietary intake indicated through remains (Clark 1954; Evans and Renfrew 1968), number and size of dwellings (Hayden 1997; Hill 1966), community size (Adams 1965; Kramer 1978), depth of deposited materials (Ammerman 1975; Ammerman et al. 1976), and radiocarbon date frequencies (Bocquet-Appel and Demars 2000; Goodale et al. 2004, 2008a; Housley et al. 1997; Pettitt 1999; Rick 1987; Surovell and Brantingham 2007;
calculating proportions of human remains in various age categories as reviewed above) to establish long-term population trends in the distant past during the transition to agriculture. The means in which we can do this are covered in detail in Chapter Six.
Summary The literature concerning the assessment of past population growth rates has increased substantially in the past two decades (Bocquet-Appel 2008) with special attention given to inferring fertility rates across the transition to agriculture in many regions of the world (Bocquet-Appel et al. 2008; Boone 2002). The link between fertility and the NDT appears at first to be fairly obvious: if there is greater fertility, there is a greater chance at producing more offspring which in turn increased population. As with many things in life, what initially appears to be a simple solution turns out to be much more complicated.
Boone (2002) argues that much of human history is characterized by periods of large-scale population decline mimicking near zero population growth. In contrast
to the form of argument used by Bocquet-Appel (2002), Boone (2002:8) asserts that:
“broad changes in population growth rates across subsistence modes in prehistory are probably best explained in terms of changes in mortality due to the dampening or buffering of crashes rather than significant increases in fertility.”
that the NDT did ni fact represent a substantial increase in the number of humans.
In reference to the NDT, the distinction depends on whether fertility significantly increased during the early part of the transition to agriculture, or whether mortality substantially decreased.
Recent research regarding the demography of human societies transitioning into settled life and resource intensification (Bocquet-Appel 2002, Bocquet-Appel et al. 2008; Bocquet-Appel and Naji 2006) has provided more in-depth analysis of longterm population trends. Even so, in archaeology actual estimates of population growth rates over such long-term trajectories during this significant transition in human history are infrequently addressed. The majority of archaeological studies that address these trends have been qualitative (Cohen 1977b; Cohen et al. 1980) with rare exceptions of quantification (Bocquet-Appel et al. 2008; Hassan 1981). But cases that attempted to quantify population growth rates during the transition are problematic because they do not represent temporally or spatially extensive population densities and focus rather on site level population estimates over a short period of time (see examples in Hassan 1981). Bocquet-Appel and colleagues have contributed toward this goal with the analysis of human remains throughout the NDT.
In this study I seek to contribute toward this goal by analyzing other variables that should be proxies for human population.
Building upon this, researchers need to reframe debate on the NDT, in order to gain a deeper understanding of the timing, rate and characteristics of the transition.
archaeological record requires a foundation for empirical investigation of the NDT and deciphering the casual structure behind its occurrence. Utilizing readily available archaeological assemblages to build population growth rate models provides the capability of assessing prehistoric demographic change associated with the NDT in many regions of the world. It is important that we corroborate the NDT model proposed by Bocquet-Appel and colleagues with other variables to test for its universality (Bocquet-Appel and Naji 2006).
One could argue that aside from genetics, the factors resting at the crux of health are nutrition and exercise. These components are cited in nearly every health magazine and book at the counters of most major supermarkets. Inherently, it seems that fertility should in some way be linked to health but exactly how is up for debate.
In this chapter I outline several concepts associated with not only detecting a NDT in the Near East, but also providing significant correlates for the NDT that may help us explain why fertility increased as well as how to resolve the apparent conflict between the evolutionary requirement of minimizing energy expenditure and the bearing and raising of more children that seem to be implied by the NDT.
In order to explain both these parameters, it is necessary to examine the archaeological correlates that may be signaling why population grew. This includes the development of storage techniques that allowed wild foods to be stored for longer than just the harvest season. Importantly, these foods are correlated with high fertility, and long-term and consistent access to them could have increased total fertility rates. Moreover, I will argue that the social impetus for investing in more children which produced the “substantial increase in human numbers” (BocquetAppel 2002), was the shifting roles of a younger aged people to the labor force, ultimately providing the ability to feed larger families.
departure in population growth rates over a defined period of time brought about through changes in birth, death, or migration. Modern demographic transition theory indicates fertility and health are important factors in demographic change. As noted, Bocquet-Appel proposes a two-phase aspect to the NDT that includes first, a dramatic increase in fertility and second, an increase in mortality due to a decrease in health (Bocquet-Appel 2002; Bocquet-Appel et al. 2008). However, a detailed discussion regarding why fertility increased at the beginning of the NDT has yet to be accomplished.
The purpose of this chapter is two-fold: to discuss the influence of subsistence on health and fertility and their influence in turn on birth, longevity, death and ultimately demographic change; and how considerations of optimality, economics, and child-rearing strategies may have favored the investment in more children. I focus on both current explanatory models and new data in the modern science of fertility that strongly correlate with the patterns we see in the NDT. I suggest that storage technology was significant not only in the organization of communities but also as a major contributor to the increase in fertility in concert with accessible foods at the start of the NDT.
The Convergence Model This chapter presents what I believe to be important components of the convergence model that can provide insight to why fertility increased when it did, and
foods associated with increased fertility and the presence of behaviorally and cognitively modern humans who interacted with those foods. Moreover, there is a series of technological inventions that result from human action that increased efficiency of harvesting and processing those resources. Two other components of behavior allowing fertility to increase included sedentism which provides certain advantages that are associated with fertility and decreased birth-spacing, as well as the development of storage technology.
My general argument here is that all of the hallmarks of what we consider the transition to agriculture are in place before major changes occurred in the socioeconomic system. What is unique is the later demonstration that until all of these hallmarks were in place, population growth rates remained low, essentially mimicking zero-growth. It is only when the convergence of these factors occurred that we begin to see population growth rates increase substantially.
As fertility increased there had to be some behavioral reorganization which underwrote the cost of having larger families, thereby allowing population to increase (Kramer and Boone 2002). This underwriting was most likely accomplished through incorporating younger, non-dependent offspring into the labor force – a phenomenon to which the ethnographic literature attests.
48 49 Figure 4.1. A theoretical model of natural occurrences, and behavioral actions converging to cause the NDT and the subsequent behavioral reactions and changes in socioeconomic systems.
those elements through a series of behavioral reactions to increasing population.
These reactions include modifications to storage technology in order to feed more people, increased sedentism with architectural modifications to house more people, increased fertility with the addition of more resource bases associated with increased fertility and an increasingly stabilized diet. The significance of each of these components are described in detail here as is their intricate association with 1) increased fertility and 2) why their convergence may have increased population growth rates causing the NDT.
Subsistence Mode and Total Fertility Rates Identifying the NDT as occurring in tandem with increasing subsistence intensification and the transition from foraging to farming, in itself, suggests that this change had at least something to do with subsistence. Subsistence intensification is defined as a process of change in socioeconomic systems where there is an increase in the return relative to land area or labor input (Morrison 1994; Prentiss et al. 2006:58).
There has been a significant debate as to how the mode of subsistence (or subsistence intensification) correlates with demographic patterns motivated by fertility and health (Bentley et al. 1993 a, b; Campbell and Wood 1988; Hewlett 1991; Sellen and Mace 1997). Specifically the debate centers on whether agriculture does or does not increase the total fertility rate (TFR or the mean number of children born to a woman over her lifetime assuming normal age-specific fertility and survival from birth to
and Wood (1988) argued that technological developments or subsistence intensification will ordinarily increase mortality rather than fertility. However, due to errors in Campbell and Wood’s (1988) dataset related to transcription as well as potential problems with categorizing a socioeconomic system as agricultural, horticultural or foraging, Bentley et al. (1993a) used a revised data set and found that people within agricultural systems have significantly higher TFR than societies relying on horticultural and forager systems.