The Neolithic demographic transition in the US Southwest

Abstract

Maize agriculture was practiced in the U.S. Southwest slightly before 2000 B. C, but had a negligible impact on population growth rates until the development or introduction of more productive landraces; the ability to successfully cultivate maize under a greater variety of conditions, with dry farming especially important; the addition of beans, squash, and eventually turkey to the diet; increased sedentism; and what we infer to be the remapping of exchange networks and the development of efficient exchange strategies in first-millenium-A.D. villages. Our estimates of birthrates and growth rates are derived from the proportions of immature individuals among human remains. These proportions are somewhat affected by warfare in our region, and perhaps also by climate. Nevertheless, there is a strong identifiable Neolithic Demographic Transition signal in the U.S. Southwest in about the mid-first-millennium A.D. in most subregions, visible a few hundred years after the introduction of well-fired ceramic containers, and more or less contemporaneous with the first appearance of villages. Independent genetic data derived from the mitochondrial genomes of present-day indigenous populations of the Southwest are also consistent with the hypothesis that a major demographic expansion occurred 1,500-2000 years ago in the Southwest.

Full text

Despite the deep hominid evolutionary his-
tory of foraging,several independent zones
of agricultural invention appeared almost
simultaneously on the planet during the Holocene,
in a chronological window from 11–3.5 ka B.P.
These were located in the Near East (wheat and bar-
ley), East Asia (rice and millet),Sub-Saharan Africa
(including poorly dated plants of three major com-
plexes [Harlan 2006]),South America (where three
complexes of species emerged at differing eleva-
tions [Pearsall 2006]),Mesoamerica (maize,beans,
gourds and squash), and eastern North America
(squash, sunflower, and the other members of the
Eastern Agricultural Complex). When agricultural
crops or farmers from these primary zones appeared
in “secondary” neighboring regions, such as the
THE NEOLITHIC DEMOGRAPHIC TRANSITION
IN THE U.S. SOUTHWEST
Timothy A. Kohler, Matt Pier Glaude, Jean-Pierre Bocquet-Appel, and Brian M. Kemp
Maize agriculture was practiced in the U.S. Southwest slightly before 2000 B.C., but had a negligible impact on population
growth rates until the development or introduction of more productive landraces; the ability to successfully cultivate maize
under a greater variety of conditions, with dry farming especially important; the addition of beans, squash, and eventually
turkey to the diet; increased sedentism; and what we infer to be the remapping of exchange networks and the development of
efficient exchange strategies in first-millenium-A.D. villages. Our estimates of birthrates and growth rates are derived from
the proportions of immature individuals among human remains. These proportions are somewhat affected by warfare in our
region, and perhaps also by climate. Nevertheless, there is a strong identifiable Neolithic Demographic Transition signal in
the U.S. Southwest in about the mid-first-millennium A.D. in most subregions, visible a few hundred years after the intro-
duction of well-fired ceramic containers, and more or less contemporaneous with the first appearance of villages. Indepen-
dent genetic data derived from the mitochondrial genomes of present-day indigenous populations of the Southwest are also
consistent with the hypothesis that a major demographic expansion occurred 1,500–2000 years ago in the Southwest.
La culture du maïs se pratiquait dans le sud-ouest des Etats-Unis avant 2000 B.C., mais eut un impact négligeable sur le taux
d’accroissement de la population jusqu’au développement ou l’introduction des variétés cultivées plus productifs; la capac-
ité de cultiver du maïs avec succès sous une grande variété de conditions, avec la culture sèche particulièrement importante;
l’addition de haricots, de courges, et éventuellement de dindes à la nourriture; l’accroissement de la sédentarité; et ce que
l’on infére relativement à la recomposition géographique des réseaux d’échanges et le développement de stratégies d’échange
efficientes dans les villages du 1er millénaire A.D. Nos estimations de taux de natalité et de taux d’accroissement dérivent des
proportions d’individus immatures dans les restes humains. Ces proportions sont quelque peu affectées par les guerres dans
notre région,et peut être aussi, par le climat. Néanmoins, il y a le signal fort d’une Transition démographique néolithique dans
le sud-ouest des Etats-Unis vers la première moitié du 1er millénaire A.D. dans la plupart des sous-régions, signal visible
quelques centaines d’années après l’introduction de containers en céramique cuite, et approximativement contemporaine avec
la première apparition de villages. Des données génétiques indépendantes provenant de génomes mitochondriaux de popula-
tions indigènes du sud-ouest aujourd’hui, sont aussi consistantes avec l’hypothèse qu’une expansion démographique majeure
se produisit là il y a 1500–2000 ans.
Timothy A. Kohler !Department of Anthropology, Washington State University, Pullman, WA 99164-4910, Crow Canyon
Archaeological Center, and Santa Fe Institute (tako@wsu.edu)
Matt Pier Glaude !Department of Anthropology, Washington State University, Pullman, WA 99164-4910
(matt_glaude@pch.gc.ca)
Jean-Pierre Bocquet-Appel !CNRS, EP 2147 44, rue de l Amiral Mouchez 75014 Paris, France
(bocquet-appel@evolhum.cnrs.fr)
Brian M. Kemp !Department of Anthropology and School of Biological Sciences, Washington State University, Pullman,
WA 99164-4910 (bmkemp@wsu.edu)
American Antiquity 73(4), 2008, pp. 645–669
Copyright ©2008 by the Society for American Archaeology
645
AQ 73(4) Kohler 10/10/08 10:56 AM Page 645

646 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
North American Southwest,the processes by which
this transfer took place—and its consequences—
are always of great interest.
In this paper we concentrate on the demographic
consequences of the introduction of Neolithic
economies (more conventionally called Formative
economies in the New World; Willey and Phillips
1958) to the U.S. Southwest. Demographic
responses over time integrate effects from tech-
nology, economy, social relations, and cultural
norms,including narrowly demographic consider-
ations such as age at weaning, postpartum sexual
taboos,etc. These responses therefore provide raw
materials for inferences concerning health, carry-
ing capacity, and sociopolitical organization—in
short,the methods, and their socionatural contexts,
by which populations nourished additional mouths
and managed the social tensions and entrepre-
neurial activities arising in an increasingly numer-
ous population in intensifiable habitats (Clarke and
Blake 1994).
Our understanding of the demographic conse-
quences of shifting to an agricultural economy has
improved with two recent methodological innova-
tions. The first is the development of a noncon-
ventional demographic indicator for use on sets of
human remains, most directly as an estimator of
the birth rate, but secondarily, if death rates are
approximately constant, as an estimator for the
growth rate. The second is the development of a
nonstandard chronological frame that makes it pos-
sible to gather information that is dispersed over
time and space to highlight otherwise undetectable
demographic patterns underlying archaeological
data (Bocquet-Appel 2002). These techniques have
allowed Bocquet-Appel (2002) to detect a major
demographic shift in a paleoanthropological data-
base of Mesolithic and Neolithic sites in Europe
and North Africa. This shift has been named the
Neolithic Demographic Transition (NDT)
(Bocquet-Appel 2002; Bocquet-Appel and Paz de
Miguel Ibanez 2002). The indicator is calculated
as the proportion of juveniles (5–19 years of age)
among all human remains ≥5 years of age, abbre-
viated as 15p5, in each site, or in groups of proxi-
mate, penecontemporaneous sites. In a growing
population, the proportion of immature individu-
als (alive or dead) is high, while in a decreasing
population,it is low (Johansson and Horowitz 1986;
McCaa 2000; Sattenspiel and Harpending 1983).
This corresponds, respectively, to a population age
pyramid with a wide or narrow base, recording a
high or low birthrate respectively and, underlying
this, an increase or decrease in fertility and growth
rates.
The assumed cause of the unprecedented rise in
human fertility during the NDT is increased seden-
tism associated with the shift from a forager to a
producer economy and the subsequent chain of
effects that shortened the duration of the repro-
ductive cycle via a reduction in the relative meta-
bolic load for the mothers (Bocquet-Appel 2008;
Valeggia and Ellison 2004). This paleodemo-
graphic indicator provides direct evidence of the
demographic process that generated the relevant
archaeological remains. Since it was detected in
Europe and North Africa, an NDT signal has been
identified in several regions of North America
(Bandy et al. 2008; Bocquet-Appel and Naji 2006;
Warrick 2006), Mesoamerica and South America
(Bandy 2005) and the Levant (Guerrero et al. 2008).
This NDT initiated the demographic regime of
preindustrial populations, with their high birth and
mortality rates (Bocquet-Appel and Naji 2006),
and its biocultural consequences are only beginning
to be explored (Bandy 2005; Bocquet-Appel and
Bar Yosef 2008).
The purpose of this article is twofold. First, we
hope to make these methods more widely known
to American archaeologists by way of their appli-
cation to the U.S. Southwest. Furthermore,we hope
to resolve long-standing debates in this region—
not so much about the timing of the introduction
of maize, which finally seems to be well under-
stood, but about the impact of early maize agricul-
ture on the degree of sedentism achieved by these
societies, or at the very least,the demographic con-
sequences of this early agriculture. Quite some time
ago, in an article that is still widely cited, Cowgill
(1975:505) urged archaeologists not to assume that
“a pervasive and powerful factor in human history
has been the strong tendency of human popula-
tions to increase up to the point where serious short-
ages of important resources are in the offing.” This
has often been read to imply that humans gener-
ally regulate their fertility efficiently, and indeed,
Cowgill himself (e.g., 1975:508) seems to doubt
the usual existence of rapid increases in population
growth following “important innovations in food
production or colonization by people with a more
AQ 73(4) Kohler 10/10/08 10:56 AM Page 646

intensive technology.” What are the facts of the
matter, so far as we can presently tell, for the U.S.
Southwest?
Early Maize in the U.S. Southwest
Following its domestication in southern Mexico
more than 6,300 years ago, maize arrived in the
southern portions of the U.S. Southwest slightly
before 2000 B.C.1(Diehl and Waters 2006; Huber
2005; L. Huckell 2006). The earliest presently
known maize sites in the American Southwest (Fig-
ure 1) do not form a strong south-to-north chrono-
logical gradient (Blake 2006; Huber 2005:Figure
36.11; Smiley 1994). For example, maize reached
northeastern Arizona by 1940 B.C. (Smiley 1994),
which is almost as early as the southern Arizona
dates. More lag can be seen in its subsequent east-
west spread—for example, it reached the Northern
Rio Grande in New Mexico by about 1200 B.C.
(Vierra and Ford 2006:505)—and in its later spread
into the northern reaches of the Colorado Plateau
in Utah,around A.D. 600 (Barlow 2006; Figure 2).
The pattern of diffusion in Figure 2 resembles the
so-called “leapfrog process” (Zvelebil 2000) from
one favorable locality to another, with dissemina-
tion occurring outwards from each location rather
than as a continuous front. While the core cultigens
of the Mesoamerican agricultural adaptation also
included beans and squash, their entrance into the
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 647
Figure 1. Location of study area and of selected sites used in the analysis.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 647

Southwest is later and less distinct. Macrobotani-
cal evidence for these plants is much less abundant
than is evidence for maize throughout southwest-
ern prehistory, and first occurrences of each are
generally in the first millennium B.C. (Smith
2001a).
So familiar is the concept of the Neolithic wave-
of-advance defined for Europe by Ammerman and
Cavalli-Sforza (1973) that archaeologists tend to
assume that this model will work elsewhere. This
model, which seeks to explain important cultural
and demographic change through the demic diffu-
sion of agriculturalists, has also been used to
explain the distribution of major language families
(Bellwood 2005; Bellwood and Renfrew 2002;
Renfrew 1987), and is consequently important to
understanding the genetic and linguistic prehistory
of the Southwest (Matson 2002). In Southwest Asia
it appears that a highly productive package of
domesticates, including animals and ceramic ves-
sels for cooking and storage,was “assembled” early
and was then able to spread rapidly from east to
west into and through Europe within zones of rel-
atively similar climate and biota. By contrast, from
its probable homeland in the tropical deciduous
forests or thorn forests of the Balsas depression in
Mexico to the U.S. Southwest,the spread of maize
was largely from south to north, demanding selec-
tion for domesticates able to thrive under novel
combinations of heat units, day lengths, and pre-
cipitation regimes (Adams et al. 2006).
The spread of maize was accompanied and to
some extent made possible by development of new
cultivation strategies. Early maize husbandry in the
Southwest apparently emphasized water-table and
overbank flood farming, although irrigation sys-
tems are now recognized from both southern Ari-
zona and the southern Colorado Plateau by only
500–1,000 years after the earliest appearances of
maize in those areas (Damp et al. 2002; Doolittle
and Mabry 2006). Presumably irrigation reduced
the risk of crop failure (Huckell et al. 2002),allow-
ing for a more sustainable and reliable use of maize.
Dry farming—essential to opening up large and
highly productive mesa tops in the northern
Southwest—was added last of all, ca. A.D. 300
(Doolittle and Mabry 2006; Kohler 1993; Matson
1991).
Except in the northernmost portions of the
Southwest a considerable lag exists between the
first appearance of maize and the development of
well-fired ceramic vessels,which regionally varies
648 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
Figure 2. Calibrated B.P. dates for earliest maize sites in the U.S. Southwest, interpolated using inverse-distance weighting.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 648

between about A.D. 1 and 500. Moreover, South-
western domesticated animals (dog and turkey)
never rivaled in dietary contribution the ovicaprids,
cattle, and pigs that yielded so much protein to
European Neolithic diets. Turkey, which has the
greater dietary importance, is relatively unimpor-
tant in diets before the A.D. 1100s in many por-
tions of the Southwest.
Finally, recent research has helped to trace
changes in the nutritional value of maize,which has
important implications for its role in prehistoric
diets (Benz 2006; Iltis 2006).Although it is not cur-
rently possible to accurately assess the yield of
Early Agricultural period (roughly, the last two mil-
lennia B.C.) maize, it does not seem to have been
particularly productive. Morphological observa-
tions underscore its very small size,with cupule size
increasing very slowly through the 2,000-year Early
Agricultural period and then more rapidly in the
first millennium A.D. (Diehl 2005). Adams
(1994:Table 16.9; L. Huckell 2006) recounts the
prehistory of maize landraces in the Southwest as
it is currently understood,demonstrating important
additions to the maize repertoire at ca. 100 B.C.,
A.D. 500, and A.D. 1000.
In short, the inhabitants of the ancient U.S.
Southwest spent some 3,000 years assembling their
Neolithic package; it was not given to them at the
outset. Considering this history, it is highly uncer-
tain whether a specific threshold that resembles the
Neolithic Demographic Transition identified in
Europe by Bocquet-Appel (2002) and in the Lev-
ant (Guerrero et al. 2008) can be identified in the
human remains of the Southwest.
Indeed, as discussed by Wills (1988),the dietary
and social importance of earliest maize use in the
Southwest has been debated for decades. Those
debates have not been entirely resolved by discov-
eries at Early Agricultural sites in the Tucson Basin
such as Milagro (Huckell et al. 1995; ca. 1100–800
B.C.),Las Capas (Mabry 1999; ca. 800–400 B.C.),
and Santa Cruz Bend (Mabry 1998; ca. 800–100
BC) even though extensive excavation showed use
of irrigation canals at Las Capas and 730 features
covering a total over 1.2 ha of excavations at Santa
Cruz Bend, which is thought to represent only 15
percent of the total site (Bellwood 2005:172). These
sites are near streams and contain pit structures,
probable storage pits,and large quantities of maize.
The presence of multiseasonal residences is sug-
gested,as is a reliance on storage for winter months.
Nevertheless, the extent to which the use of
maize affected other aspects of those societies
adapting it during the Early Agricultural period
remains an open question. In part,this reflects a lack
of consensus as to how productive early maize was,
as well as how dependent early populations were
on agriculture. Some researchers (e.g., B. Huckell
1995:127–133) argue that such usage was rela-
tively intensive and precipitated significant
increases in sedentism. A program of fluoride dat-
ing on one of the latest of these sites, Los Pozos,
however, suggests that what looks like a large set-
tlement with many contemporaneous households,
from the perspective of the chronological resolu-
tion available from 14C dating, is more likely a
series of small settlements containing short-lived
structures occupying a favored locale over several
centuries (Schurr and Gregory 2002). Based on
decreases in diet breadth from ca. 1200 B.C. to the
local onset of the Early Ceramic period ca. A.D.
150 in southern Arizona, Diehl and Waters (2006)
have argued that floodplain agricultural intensified
markedly early in the first millennium A.D. with
the appearance of high-quality ceramic containers
that may have significantly reduced maize seed
storage losses.
Further north, on the Rainbow Plateau in north-
eastern Arizona and in Grand Gulch, Utah, Geib
and Spurr (2002) consider the earliest evidence of
intensive agriculture to date to approximately 300
B.C. Gumerman and Dean (1989:111) use ca. 600
B.C. as the date by which they consider use of
domesticates to be common on neighboring Black
Mesa, Arizona. Both of these dates lag the first
appearance of maize in northeastern Arizona by
well over a thousand years. Matson and Chisholm
(1991) used stable isotope analyses of Basketmaker
II human remains and analysis of pollen and macro-
fossil concentrations in rockshelter middens and
coprolites in SE Utah to suggest fairly intensive use
of maize by ca. A.D. 1. Coltrain et al. (2007) have
now pushed this date back to ca. 400 B.C. for adja-
cent portions of NE Arizona by a comprehensive
program of radio- and stable-isotope analysis of
Basketmaker II human remains. Some archaeolo-
gists, however, have worried that these stable iso-
tope determinations are affected by other sources
of C4 or CAM plants on the landscape (Wills
1992:159), and it is also possible that this apparent
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 649
AQ 73(4) Kohler 10/10/08 10:56 AM Page 649

intensive usage is somehow embedded in rather
mobile settlement strategies.
In overview, although we know much more now
than we did 25 years ago about the time of the
arrival of maize in most areas of the Southwest,
much about the importance and impact of prece-
ramic maize cultivation in the U.S. Southwest
remains contested. Researchers in various areas,
basing their interpretations on various combina-
tions of evidence from architecture,settlement pat-
terns,floral and faunal remains,ceramic materials,
and stable isotopes from human bone have drawn
differing conclusions as to the importance and con-
sequences of maize agriculture.
In this paper we use Bocquet-Appel’s (2002)
method for determining population growth rates
directly from age distributions of human skeletal
remains. This adds a new and fundamental per-
spective on the importance of agriculture, and
employs a single proxy that can be applied consis-
tently across sites and regions. We will contribute
to understanding the processes by which farming
became central to agriculturalists in the U.S. South-
west by answering the following questions:
• Was there a Neolithic Demographic Transition
(NDT) in this region that can be recognized with
existing data?
• If so, does it coincide with the earliest appear-
ance of Mesoamerican domesticates, or was it
triggered only by later, presumably more inten-
sive use—and if so, when?
• If a regional NDT exists,does it differ from that
suggested for Europe by Bocquet-Appel
(2002)? In what ways, and why?
Investigating the NDT in the US Southwest
NDT theory predicts a relatively abrupt increase in
the proportions of immature individuals (ages
5–19) among all individuals aged ≥5 years old,for
some 500–700 years following the local onset of
the Neolithic. This paleodemographic indicator—
abbreviated as 15p5by demographers—is highly
correlated with both the crude birthrate (r2 ≥ .96)
and with the growth rate (r2 ≥ .875) (Bocquet-Appel
2002:643; Bocquet-Appel and Naji 2006:342) in a
sample of preindustrial populations under the sta-
ble demographic population model. Therefore,
increases in 15p5reflect increases in crude birth rate,
via a fertility increase, probably because of
decreased birth spacing accompanying sedentism
(Bocquet-Appel and Naji 2006:349), rather than a
decrease in mortality (see also Ammerman and
Cavalli-Sforza 1984:63–66). Eventually, though,
this increase in birth rates is offset by an increase
in mortality due, Bocquet-Appel and Naji
(2006:349) suggest, to the emergence of new
pathogens, especially zoonoses, with aggregation.
Data Collection and Methods
To determine whether an NDT exists in the U.S.
Southwest, we have compiled data from as many
relatively large, well-dated assemblages of human
remains as we could find. We began with compi-
lations by Kramer (2002) and Bocquet-Appel and
Naji (2006:349).2To these we added the other
assemblages in Tables 1 and 2. Our sample is not
comprehensive,though it is more complete for the
eastern Pueblo areas (central and northern New
Mexico and Southwest Colorado) than for the
remainder of the Southwest. We follow Bocquet-
Appel’s (2002; see especially on-line supplemen-
tal materials) methods for quantifying the
proportions of individuals aged 5–19 in these
assemblages. For example, these proportions are
calculated against a total that excludes individuals
below the age of 5. We excluded assemblages obvi-
ously affected by massacres or extreme perimortem
processing possibly indicating cannibalism. In
cases where counts of individuals had to be reap-
portioned from age categories that crosscut those
used here, we used rules from Boquet-Appel
(2002:on-line supplemental materials) or followed
advice from Stephan Naji (personal communica-
tion 2006).
Because it does not allow comparisons of asso-
ciations between farming and demographic events
occurring at different dates, the usual absolute (his-
torical) chronology has been abandoned.3Absolute
chronology masks temporally distant statistical reg-
ularities that need to be compared in attempting to
detect the signature of a global population process
that occurs according to a local time scale in dis-
parate locations. Consider, for example, the con-
temporary demographic transition, which began at
the end of the eighteenth century in regions as dis-
tant as New England in North America and Nor-
mandy in France,and spread from region to region,
at different times and speeds, reaching Southeast
Asia in the 1970s (Bocquet-Appel and Jakobi 1998;
650 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
AQ 73(4) Kohler 10/10/08 10:56 AM Page 650

Bocquet-Appel et al. 2002). How can this transi-
tion, representing a transcultural demographic
process, be linked with data like those mentioned
above, to facilitate its recognition as a single demo-
graphic process highly dispersed over space and
time? As indicated,we replace the absolute chronol-
ogy with a chronology relative to the duration that
elapsed locally from the start of a major cultural
shift up to the date of the demographic indicator,
or the dates of other relevant cultural changes such
as, for example, the appearance of public spaces
(Bocquet-Appel and Dubouloz 2003, 2004), of a
social hierarchy,of a defined size of village unit,of
ceramic containers, etc. The change to a relative
chronology (in years dt) makes it possible to gather
information that is dispersed over space and time
and to position it within a common temporal frame.
This interpretation of the relative chronology has
been discussed elsewhere (Bocquet-Appel 2002,
2005; Bocquet-Appel and Dubouloz 2004;
Bocquet-Appel and Paz de Miguel Ibanez 2002).
Also following Bocquet-Appel, we use a
method of fitting the bivariate relationship between
15p5and years dt that is unfamiliar to most archae-
ologists. Because we expect the relationship
between these two variables to change across the
span of years dt, and because statistical inference
is less important to us than is characterizing that
relationship, we use loess fitting (local regression).
This nonparametric procedure fits parametric func-
tions “locally in the space of the predictors [here,
years dt] using weighted least squares in a moving
fashion similar to the way a time series is smoothed
by moving averages” (Cleveland and Grosse
1991:47). Our statistical procedure and sampling
did depart from Bocquet-Appel’s analysis routine
in one way. Because the assemblages we used
ranged greatly in size, from 5 to 551 individuals,
we weighted assemblages according to their sam-
ple sizes in the loess algorithm. This limits the influ-
ence of the sampling errors that are unavoidable in
small assemblages on the fits obtained. Practically
speaking, this also makes it unnecessary to aggre-
gate small samples that are close in space and time.
In producing the loess graphs discussed below,
except where otherwise noted, we allowed our fit-
ting routine4to determine the size of the window
used (Bocquet-Appel’s α), within a permissible
range of .3–.6, so as to minimize the AICcvalue
(Hurvich et al. 1998).
Results
To examine the relationship of this paleodemo-
graphic indicator to the first arrival of maize, we
use the estimates for the first use of maize in each
site’s region or subregion, as reported in Table 1,
to set the zero point for the dt time scale. Figure 3
thus graphs, on its x-axis, the difference between
the midpoint date for each assemblage of human
remains and the date for the introduction of maize
to that subregion, against the proportion of indi-
viduals from each site aged 5–19 on the y-axis. The
horizontal dashed line represents an estimate for
the location of a growth rate (r) of zero, based on
simulations on 45 reference life tables as explained
by Bocquet-Appel (2002:639–640). The dt = 0
point marks the location of the time- and space-
transgressive first appearances of maize as presently
understood.
It is immediately apparent that we have no sites
with enough human remains to graph that are within
500 years of the first local introduction of maize.
Given the density of excavation in the U.S. South-
west, this seems to imply that for almost 500 years
following first local appearance of maize, popula-
tions remained low, and perhaps relatively mobile
(see also Coltrain et al. 2007; Diehl and Waters
2006; Simmons 1986). Figure 3 suggests that pop-
ulation growth rates began to increase some 1,500
years after the first appearance of maize, and that
growth rates peaked some two millennia after the
local introduction of maize, declined over the next
700 years, and then increased once more. Both the
first increase, and the decline, are interpretable in
terms of NDT theory, though this first increase
comes almost 1,500 years later than expected. The
second increase is somewhat unexpected, and we
return to it below.
Perhaps we would see a better fit between the
Southwestern data presented here and the NDT
graphs of Bocquet-Appel (2002) for Europe and
Bocquet-Appel and Naji (2006) for North Amer-
ica (where they include a few sites from the South-
west) if we examined the relationship between the
proportion of 5–19-year-olds and an estimate for
the earliest intensive use of maize. Bocquet-Appel
and Naji (2006, Table 1) use A.D. 200 as the date
for the introduction of maize throughout the South-
west except for Casas Grandes (Paquimé) where
they use a date of A.D. 700. These dates are much
more in line with the local appearance of ceramics
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 651
AQ 73(4) Kohler 10/10/08 10:56 AM Page 651

652 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
Area/Site (Abbreviation for figu res) Subregion
Site
date
(A.D.)
Early
Maize
(A.D.)
Effective
use of
Maize
(A.D.)
dt Early
Maize
dt
Effective
Maize n(5+) 5–19 19+ 15p5Sources
Hohokam Area
CienegaaTucson Basin -125 -2000 150 1875 -275 55.00 13.00 42.00 .236 Mabry 1998:Table 16.2
Las Capas (LasCapa) Tucson Basin -1000 -2000 150 1000 -1150 11.00 2.75 8.25 .250 McClelland in Diehl 2005
Matty Washa(MattyWa) Tucson Basin -443 -2000 150 1557 -593 15.00 2.00 13.00 .133 Huckell 1995:Table 3.5
SA Mission (SAMissi) Tucson Basin -38 5 -2000 150 1615 -535 12.00 1.80 10.20 .150 McClelland 2008
Pueblo Grande-Early Classic (PGEC) Phoenix Basin 1213 -2000 150 3213 1063 88.67 19.67 69.00 .222 Sheridan in Mitchell and Brunson-
Hadley 2001
Pueblo Grande-Late Classic (PGLC) Phoenix Basin 1363 -2000 150 3363 1213 61.33 13.33 48.00 .217 Sheridan in Mitchell and Brunson-
Hadley 2001
Roosevelt Platform Mound Study-
Roosevelt Phase (RPMS-RP) a
Tonto Basin 1300 -2000 150 3300 1150 102.50 18.50 84.00 .180 Ravesloot & Regan 2000:62
Schoolhouse Point Mound -Gila Phase
(RPMS-GP)
Tonto Basin 1400 -2000 150 3400 1250 61.00 13.00 48.00 .213 Ravesloot & Regan 2000:62
Mogollon Area
Casas Grandes (Paquimé) Chihuahua 1300 -2000 1 3300 1299 550.80 220.32 330.48 .400 Bocquet-Appel & Naji 2006:243
Galaz-Late Pithouse (Galaz LP) Mimbres 775 -2000 1 2775 774 64.75 24.42 40.34 .377 Anyon & Leblanc 1984
Galaz-Classic Mimbres (GalazCM) Mimbres 1075 -2000 1 3075 1074 540.75 161.69 379.06 .299 Anyon & Leblanc 1984
Grasshopper Pueblo (Gra ssho) Cib ecue 1338 -2000 1 3338 1 337 279.00 90.00 189 .00 .323 Bocquet-Appel & Naji 20 06:243
Point of Pines (Pointof) Black River 1275 -2000 1 3275 1274 333.00 37.00 296.00 .111 Bocquet-Appel & Naji 2006:243
SU Cibola 500 -2000 1 2500 499 27.00 3.00 24.00 .111 Buzon & Grauer 2002:Table
1
Pueblo Area
423-101 San Juan Basin 900 -980 300 1880 600 9.00 1.00 8.00 .111 Herrmann et al. 1993:12
Arroyo Hondoa (ArroyoH) Northern Rio Grande 1363 -1250 300 2613 1063 59.00 18.00 41.00 .305 Bocquet-Appel & Naji 2006:243
Black Mesa-Early Puebloa (BMEarly) Kayenta 925 -1900 60 0 2825 325 35.43 10.43 25.00 .294 Martin et a l. 1991:Table 2--1 1
Black Mesa-Late Puebloa (BMLate ) Kayenta 1100 -1900 600 3000 50 0 79.00 23.00 56.00 .291 Martin et al. 1991:Table 2--11
Darkmold-5LP4991 (Darkmo) La Plata 200 -400 500 600 -300 22.60 8.23 14.38 .363 Charles, ed. 200 0; Charles 2007
Dog Leg Site (DogLeg) San Juan Basin -290 -980 300 690 -590 10.50 4.85 5.65 .462 Kea rns et al. 1998
DurangoaLa Plata 750 -400 500 1150 25 0 5.00 .00 5.00 .000 Rowen III 1980 :Table 24
Duna Leyenda-42Sa8540 (DunaL) Northern San Juan 600 -400 300 1000 300 10.00 1.50 8.50 .150 Neily 1982:64--103
Gran Quivira-Early (Gran QuE) Northern Rio Grande 137 6 -1250 300 2626 1 076 22.00 3.00 19.00 .136 Hayes 19 81
Gran Quivira-Middle (Gran QuM) Northern Rio Grande 14 75 -1250 300 2725 1175 49 .33 13.00 36.33 .264 Ha yes 1981
Gran Quivira-Late (GranQuL) Northern Rio Gra nde 1611 -1 250 300 2861 1 311 60.33 10.00 50.33 .1 66 Haye s 1981
Hawikku LA37 Zuni 1563 -2000 300 3563 1263 147.00 44.00 103.00 .299 Bocquet-Appel & Naji 2006:243;
Stodder 1994
La Plata La Plata 1100 -4 00 500 1500 600 41.00 11.00 30.00 .268 Martin & Ak ins 2001
Marsh Passa (MarshPa) Kaye nta -233 -190 0 600 1667 -833 21.00 2.63 18.37 .125 Coltrain et al. 2007:Table 1
NRG - 1150aNorthern Rio Grande 1150 -1250 30 0 2400 85 0 17.96 2.19 15 .77 .122 Krame r 2002:Appendix D
NRG - 1250aNorthern Rio Grande 1250 -1250 300 2500 95 0 17.02 2.42 14 .60 .142 Krame r 2002:Appendix D
Table 1. Sites Used in Analysis of Southwestern Demographic Data.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 652

Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 653
NSJ - 850aNorthern San Juan 850 -400 300 1250 550 86.14 20.74 65.40 .241 Kramer 2002:Appendix D
NSJ - 950aNorthern San Juan 950 -400 300 1350 650 20.40 3.40 17.00 .167 Kramer 2002:Appendix D
NSJ - 1050a + Porter-5MT1 Northern San Juan 1050 -400 300 1450 750 43.28 9.26 34.02 .219 Kramer 2002:Appendix D &
Swedlund 1966
NSJ - 1150a + 5MT3Northern San Juan 1150 -400 300 1550 850 77.77 29.97 47.78 .385 Kramer 2002:Appendix D &
Swedlund 1966
NSJ - 1250aNorthern San Juan 1250 -400 300 1650 950 82.30 25.75 56.55 .313 Kramer 2002:Appendix D
Pecos Pueblo-Forked Light
(
PecosFL)
Northern Rio Grande 1225 -1250 300 2475 925 99.33 19.33 80.00 .195 Mobley 1980
Pecos Pueblo-Glaze/B&W
(PecosBW)
Northern Rio Grande 1338 -1250 300 2588 1038 39.57 9.57 30.00 .242 Mobley 1980
Pecos Pueblo-Glaze I (PecosG1) Northern Rio Grande 1400 -1250 300 2650 1100 118.71 20.71 98.00 .174 Mobley 1980
Pecos Pueblo-Glaze II (PecosG2)Northern Rio Grande 1450 -1250 300 2700 1150 69.86 8.86 61.00 .127 Mobley 1980
Pecos Pueblo-Glaze III (PecosG3)Northern Rio Grande1513 -1250 300 2763 1213 122.71 19.71 103.00 .161 Mobley 1980
Peña Blanca-E. Devel
(PBED)
Northern Rio Grande 700 -1250 300 1950 400 12.25 3.25 9.00 .265 Akins 2008
Peña Blanca-L. Dev/Coal
(PBLDEC)
Northern Rio Grande 1200 -1250 300 2450 900 8.25 3.25 5.00 .394 Akins 2008
San Cristóbal (SanCris) Northern Rio Grande 1503 -1250 300 2753 1203 203 .00 55.00 148.00 .271 Bocquet-Ap pel & Naji 2006:243
SJB - 700aSan Juan Basin 700 -980 300 1680 400 43.94 9.54 34.40 .217 Kramer 2002:Appendix D
SJB - 850aSan Juan Basin 850 -980 300 1830 550 42.76 9.51 33.25 .222 Kramer 2002:Appendix D
SJB - 945a (UpPuerc)San Juan Basin 945 -980 300 1925 645 32.17 9.17 23.00 .285 Herrmann et al. 1993:12–14
SJB - 950aSan Juan Basin 950 -980 300 1930 650 89.85 36.75 53.10 .409 Kramer 2002:Appendix D
SJB - 1050aSan Juan Basin 1050 -980 300 2030 750 139.74 38.69 101.05 .277 Kramer 2002:Appendix D
SJB - 1150aSan Juan Basin 1150 -980 300 2130 850 222.63 91.43 131.20 .411 Kramer 2002:Appendix D
SJB - 1250aSan Juan Basin 1250 -980 300 2230 950 26.76 12.04 14.72 .450 Kramer 2002:Appendix D
Stevenson-5MT1 (Stevens)Northern San Juan 660 -400 300 1060 360 5.00 .00 5.00 .00 Swedlund 1969
a Composite samples; see Table 2 for additional information.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 653

654 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
Area/Site
Number
of sites n(5+) Sites Largest Contributing Site Co mment
Hohokam
Cienega 7 55.00 Coffee Camp (AZ AA:6:19),Wetlands (AZ AA:12:90), S. C ruz Bend (AZ
AA:12:746), Stone Pipe (AZ A A:12:745), Los Pozos (AZ AA:12:91 ),
Clearwater (AZ BB:13:6), Pan tano (AZ EE:2:5)
AZ AA:12:90 (Wetlands), n=21 Compilation of sites from sou th-central
Arizona
Matty Wash 2 15.00 Donaldson Site, Los Ojitos Los Ojitos, n=10
Roosevelt Platform
Mound Study-
Roosevelt Phase
2 102.5 Sch oolhouse Point Mound (U:8:24) and U:8:4 50 Scho olhouse Point Mound Popu lations with dental traits suggesting
mixed Sinagua and western Anasazi
affiliations
Pueblo
Black Mesa - Early
Pueblo
13 35.43 7:98, 7:134, 7:135, 7:262, 7:234, 7:707, 7:2103,11:2023, 11:2025, 11:2030,
11:2040,11:2062, 11 :2068
7:234 (n=8) Compilation of Black Mesa sites dating to
A.D. 800–1050
Black Mesa - Late
Pueblo
39 79.00 7:11, 7:12, 7:23, 7:27, 7:102, 7:109, 7:216, 7:716, 7:719, 7:220, 7:725, 7:2001,
7:2017, 11:3, 11:12, 11 :14, 11:97, 11:260, 11:265, 11:275, 11:289, 11:290,
11:300, 11:335,11:348, 11:352, 11:409, 11:425, 11:426, 11:500, 11:569, 11:666,
11:686, 11:687, 11:2013, 11:2048, 11:2068, 11:2108, 11:2155
11:500 (n=7), 11:300 (n=7) Compilation of Black Mesa sites dating to
A.D. 1050–1150
Durango 2 7.00 5LP110, 5LP11 1 5LP11 (n=3)
Marsh Pass 4 21.00 Say odneechee Cave, Kinboko Cyn Cave 1, White Dog Cave, Tsegi Canyon
Cave 3
Sayodneechee Cave, n=9 Compilation of e arly Kayenta sites
NRG - 1150 4 17.96 LA6 49, LA6865, LA11633, LA654 LA649 (Nogales Cliffho use),
n=11
Compilation of Gallina sites da ting to A.D.
1100–1199
NRG - 1250 9 17.02 LA1 1843, LA22866, LA22867, LA22868, LA22895, LA22902, LA23043,
LA11850, LA11841
Even distribution of bu rials Compilation of Gallina sites dating to A.D.
1200–1300
NSJ - 850 16 86.14 5MT2192, 5MT2848, 5MT2853, 5MT5107, 5MT2182, 5MT23, 5MT4671,
5MT4725, 5MT2320, 5MT4475, 5MT5108, 5MT4480, 5MT1604, 5MT8899,
5MT8937, 5MT3868
5MT5107 (Pueblo de las
Golondrinas), n=19
Compilation of region al sites dating to A.D.
800–899
NSJ - 950 5 20 .4 5MT4477, 5MT2525, 5MT8934 , 5MV1452, 5MV875 5MV1452 (Badge r House),
n=11
Compilation of region al sites dating to A.D.
900–999
NSJ - 1050 7 31.78 5 MT5501, 5MT5106, 5MT8827, 5MT2433, 5MV1452, 5MV866, 5MV1229 5MV1452 (Badger House),
n=12
Compilation of region al sites dating to A.D.
1000–1099
NSJ - 1150 10 65.77 5MT5498, 5MT2149, 5MT2235, 5MT948, 5MT2148, 5MT2544, 5MV1595,
5MV499, 5MT7723, 5MT10207
5MV1595, n=20 Compilation of re gional sites dating to A.D.
1100–1199
Table 2. Details on Composite Burial Assemblages.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 654

Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 655
NSJ - 1250 7 82.3 5MT9735, 5MV34, 5MV1452, 5MV1 200, 5MV1228, 5MV1229, 5MT10206 5 MV1200 (Long House), n=28 Co mpilation of regional sites dating to A.D.
1200–1300
SJB - 700 10 43 .94 LA45689, LA2507, LA8939 , LA16029, LA4195, LA8662, LA80407 , LA83505,
LA083506, LA83507
LA4195 (Sambrito Village ),
n=16
Compilation of region al sites dating to A.D.
600–799
SJB - 850 12 42 .76 LA3562, LA4487, LA3646, LA4363, LA4384, LA4151, LA4131 , LA4148,
LA4242, LA4198, LA80934, LA83507
LA4487, n=15 Compilation of region al sites dating to A.D.
800–899
SJB - 945 5 32.17 423-122, 423-124, 423-129, 423-130, 423-131 423-124, n=12.67 Upper Puerco River sites from A.D. 285–
1410, dates averaged
SJB - 950 16 89 .85 LA50337, LA4169, LA429 8, LA4380, LA4131, LA4053, LA4086, LA40 88,
LA2585, LA226, LA40 299, LA40626, LA40627, LA40935, LA41629,
LA83506
LA4086 (Sanchez Site), n=27 Compilation of regional sites dating to A.D.
900–999
SJB - 1050 35 139.74 LA16660, LA104984, LA8846, LA80440, LA59497, LA2675, LA2699,
LA2701, LA2937, LA50 62, LA6383, LA6387, LA16254, LA8779, LA2585,
LA2592, LA80377, LA40395, LA226, LA838, LA841, LA2470, LA40394,
LA40396, LA40399, LA40597, LA40626, LA42385, LA83498, LA100627,
LA100628, LA100629, LA83500
LA40399 (Tom Mathew 's Dig),
n=19
Compilation of region al sites dating to A.D.
1000–1099
SJB - 1150 17 222 .63 LA45, LA8846, LA5057, LA22 6, LA2985, LA2987, LA2988, LA2470,
LA40394, LA40396, LA2 464, LA8978, LA40395, LA40397, LA4072 1,
LA2592, LA40399
LA226 (Pueblo Bonito ), n=62 Compilation of region al sites dating to A.D.
1100–1199
SJB - 1250 17 26.76 LA3292, LA45, LA8846, LA852 35, LA5596, LA2714, LA4485, LA6372 ,
LA6380, LA6400, LA35867, LA41947, LA2508, LA4050, LA403 99, LA40589,
LA40633
LA45 (Aztec Ruin) Compilation of regional sites dating to A.D.
1200–1300
AQ 73(4) Kohler 10/10/08 10:56 AM Page 655

than they are with the first appearance of maize
(Table 1).
Crown and Wills (1995) and Diehl and Waters
(2006), drawing from both local reasons and
theory-based arguments, suspect that the earliest
well-fired ceramic containers coincide with increas-
ingly intensive use of cultivated plants and
markedly increased sedentism. On the other hand,
Coltrain et al. (2007) provide much new evidence
based on stable carbon isotopes that maize was a
staple for Basketmaker II populations in the Four
Corners area by 400 B.C., some 700 years before
the first local appearance of ceramic containers (see
also Chisholm and Matson 1994; Matson and
Chisholm 1991). These determinations may be
somehow affected by other sources of C4 plants on
the landscape, though, and in any case we do not
presently have enough samples of stable-carbon
isotopic data throughout the Southwest to draw
exclusively on that line of very direct evidence.
Finally, it is possible that this apparent intensive
usage was somehow embedded in rather mobile set-
tlement strategies. Therefore, in a second analysis
we use the local first appearance of well-fired
ceramic vessels as a surrogate for the first local
intensive use of maize among relatively sedentary
populations. Here we will set the value of dt = 0 as
the time of the local introduction or development
of efficient ceramic containers.
Figure 4 shows the relationship between
15p5and
the earliest local intensive use of maize as proxied
from the appearance of ceramic containers. This
graph indeed resembles that produced by Bocquet-
Appel for Europe (2002:Figure 4) more than did
our Figure 3. Seven data points, all with relatively
small assemblages, predate the intensive use of
maize estimated in this way. Of these, five have low
15p5values relatively near the estimate for r= 0. As
656 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
Figure 3. Proportions of immature individuals in sites and composite samples plotted against the difference between ear-
liest maize use in that site’s subregion, and midpoint date of site occupation. Relationship fitted using loess, a nonpara-
metric method for estimating local regression surfaces (α[smoothing parameter]=.56; AICC= .89; fit method = kd tree;
nfitting points = 17; nobservations = 51; npoints in local neighborhood = 28). See note 4 for inferential test.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 656

a group the pre-dt = 0 proportions are quite vari-
able,which contributes to the wide 80 percent con-
fidence intervals. Some of this variability is
undoubtedly due to small sample sizes, but there
is also a suggestion in the data that, for some rea-
son, early maize agriculture was more successful
in the central portions and on the northeastern mar-
gins of the Colorado Plateau than it was further
south or west. Unlike the European case, however,
the 15p5values (and presumably the underlying
growth rates r) appear to begin to increase markedly
not around dt 0,but rather some 300 years after the
first local use of ceramic containers. Of course, the
dearth of data between about dt –300 and almost
300 weakens this suggestion considerably. If this
is correct, though, it would suggest that intensive
maize use (as proxied by first ceramic containers)
perhaps slightly increased population growth rates,
but that some other factor,generally occurring later,
was even more important. Comparison of Figures
3 and 4 suggests that birth rates increased—but
very slowly—following the first use of maize into
the period of intensive maize use, and then
increased rapidly in local sequences some 300 years
after intensive use is established.
Interestingly, the loess lines in both of our fig-
ures peak at a 15p5value slightly over .3, quite sim-
ilar to the maximum plotted by Bocquet-Appel
(2002:Figure 2) for the Near Eastern and European
Neolithic data. It is somewhat surprising to us that
growth rates as high as those seen in the Near East
and Europe,with their mixed farming that included
several domesticated animals, could be achieved in
the Southwest, with no significant domesticated
source of protein and fat during the period of max-
imum growth.
The decline in the 15p5values beginning about
dt 900 until about dt 1200 in Figure 4 seems to be
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 657
Figure 4. Proportions of immature individuals in sites and composite samples plotted against the difference between ear-
liest intensive maize use in that site’s subregion, as proxied from appearance of ceramic containers, and midpoint date
of site occupation. Relationship fitted using loess, a nonparametric method for estimating local regression surfaces
(α=.52; AICC= .89; fit method = kd tree; nfitting points = 17; nobservations = 51; npoints in local neighborhood = 26).
See note 4 for inferential test.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 657

associated with the period of the retrenchment of
population from the Northern San Juan and the San
Juan Basin into the Northern Rio Grande at sites
like Pecos, Gran Quivira, and into some portions
of the Mogollon area, for example Point of Pines.
There appears to have been great variability in 15p5
values in sites in these destination areas, though,
and some large, late assemblages with high 15p5
values—for example San Cristobal, Hawikku,and
Grasshopper—raise the fitted curve unexpectedly,
on the eve of the Spanish entrance to the South-
west in 1540.
In Figure 5 we experiment with applying dif-
ferent values for the smoothing parameter αto the
data graphed in Figure 4. The major features dis-
cussed above are also apparent in the other smooth-
ings, indicating that our interpretations are not
sensitive to the αparameter chosen. For compari-
son Bocquet-Appel (2002) used αvalues ranging
from .3 (Figure 4) to .5 (Figure 2).
Discussion
The first marked increasein the 15p5values, begin-
ning around dt 400 (Figure 4),corresponds in a gen-
eral way to the first pulse of aggregation in the
Southwest, where it is perhaps most striking in the
Northern San Juan Pueblo I villages (Wilshusen
1999b; Wilshusen and Perry 2008; see Bandy 2008
for a global perpective). This coincidence could be
due to some advantages of economic efficiency
among early aggregates. Alternatively, or addi-
tionally, it could reflect growth induced through
competitive processes, including aggrandizement,
in these milieus, which provided increasingly
important arenas for social advancement. Of
course, these villages were also undergoing the
pithouse-to-pueblo transition, which ethnographi-
cally tends to mark a more permanent (across
years), less mobile (across seasons within a year)
settlement system (Gilman 1987). This rapid demo-
graphic expansion also generally corresponds to the
658 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
Figure 5. Data as in Figure 4, using scatterplot smoothing parameters from .3 to .6 and fit method=direct.
AQ 73(4) Kohler 10/10/08 10:56 AM Page 658

first appearances of Maís Blando and Harinosa de
Ocho (Maís de Ocho) ca. A.D. 500–700 (Adams
1994), and follows shortly on both the opening of
a vast new agricultural niche with the development
of successful dry-farming strategies, and the intro-
duction of the bow and arrow. The growth rates
toward the top of the peak may also be underwrit-
ten by increased use of turkey for protein ca. A.D.
1100 (Cowan et al. 2006).
Warfare Inflates the 15p5Proportion
Of course, we expect the 15p5measure to be noisy
for a variety of reasons relating to the archaeolog-
ical and analytical contexts, including but not lim-
ited to: possible variability through time and space
in mortuary practices and preservation for children
and adolescents vs. adults, differences in analytic
standards for (and expertise in) determining ages
for human remains, changes through time in how
these decisions are made by bioarchaeologists,
sampling error,and so forth. To the extent that these
are random errors they will weaken, but not bias,
the fitted relationship between the 15p5value and
time relative to agricultural innovation.
Additionally,there are processes in the systemic
context that may tend to bias the signal, and these
are of somewhat greater importance. The first of
these is worthy of mention but possibly not of great
concern in itself, since while it may lead to local
anomalies in 15p5, these should be balanced out in
the regional datasets compiled in Table 1. This is
the recent argument by Kohler and Turner (2006;
Kramer 2002) that Chacoan centers, in at least the
eleventh and thirteenth centuries, seem to be
importing women from outlying regions, possibly
through raiding activities.
Although this effect per se might not bias our
results when these are averaged over large enough
spaces, the warfare that probably underlies these
patterns might cause biases. Warfare differentially
affects young adults, and could therefore, in prin-
ciple at least, raise the 15p5values in some of the
assemblages considered here by depressing the
denominators for these proportions.5
Kramer (2002) constructed life tables for many
of the composite samples reported in Table 1, and
compared the tables she constructed for each cen-
tury in each region with a composite table con-
structed from all the samples in that region,
aggregated through time. Specifically, she com-
pared the cumulative proportions of numbers of
individuals in each category, after smoothing as
outlined by Weiss (1973), between each tempo-
rally specific subsample and the entire population
from that region, including that subsample, using
a Kolmogorov-Smirnov test. This approach is obvi-
ously conservative because the sample from each
century also contributes to the regional distribution
with which it is being compared, and also, to a
smaller extent, because of the smoothing before the
test.
In the San Juan Basin region, only one century,
the 1200s, is anomalous on this measure, with sig-
nificantly more individuals in the 6–25-year-old age
groups than in the regional sample pooled by period,
and as a result,fewer individuals in the 36–55-year-
old age categories (Kramer 2002:67). Indeed, we
can see in Figures 3 and 4 that this sample (SJ1250)
has one of the highest 15p5values in our entire
dataset, although since the sample size is relatively
small its effect on the fitted line is not large.
A similar though slightly weaker effect is seen
in the contemporaneous assemblages from the
Northern San Juan region to the north. In the 1200s,
all age categories between 3- and 25-years-old are
overrepresented relative to the assemblage repre-
senting all other periods from that region (Kramer
2002:91). This effect is no longer statistically sig-
nificant,though, if the assemblages from the 1200s
are included in the composite assemblage with
which the 1200s are being compared. It is not sur-
prising,then, to see that the data point for this cen-
tury (NSJ1250) is slightly above the fitted line in
both Figures 3 and 4, though it is not among the
highest proportions in the dataset.
Taken together, we conclude that the 15p5pro-
portions are at least somewhat affected by warfare-
related processes in the Southwest, conflating as
they do high values for these proportions due to
depressed denominators reflecting high warfare-
induced mortality in young adults, with the high
values due to high numerators for the proportions
that the index is intended to measure.
Climate Plays a Role in
Limiting Southwest Growth Rates
Maize agriculture was surprisingly slow to reach
some of the higher, better-watered, northern por-
tions of the U.S. Southwest. In the Central Mesa
Verde region, for example, there are relatively few
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 659
AQ 73(4) Kohler 10/10/08 10:56 AM Page 659

Basketmaker II habitations, and Basketmaker III
sites become common only after A.D. 580 or 590
(Lipe 1999; Wilshusen 1999a). Because agriculture
in this area seems to have been highly productive
during most of the A.D. 600 to 1300 span, appar-
ently supporting considerable immigration to the
area (Varien et al. 2007), an earlier arrival of inten-
sive agriculture might have led to an earlier NDT
signal in our data.
However, this appears to have been impossible
given the prevailing climatic conditions in the first
half of the first millennium A.D. Recent well-dated
pollen cores from Beef Pasture in the La Plata
Mountains in southwestern Colorado, analyzed and
reported by Aaron Wright (2006), reveal a low-
frequency increase in the Ponderosa-pine-to-spruce
pollen ratios from historically low values ca. 100
B.C. through around A.D. 700, when they again
decline,only to increase again slightly before A.D.
1000. Wright argues that these ratios are sensitive
to annual temperature and to winter precipitation,
so that low values indicate cold and/or winter-dry
conditions. When interpreted in conjunction with
contemporaneous low-frequency trends in sedge-
to-Cheno-Am pollen ratios,in which increases are
believed to reflect increases in winter precipitation,
the period between A.D. 300 and almost 600
appears to be both cold and dry. These data strongly
suggest the prevalence of cold conditions in the
northern San Juan from at least 100 B.C. (when this
record begins) to almost A.D. 600—excepting a
short period with average conditions around A.D.
300.
Charles and Cole (2006:167–216) have recently
tabulated all the known tree-ring and 14C dates for
Basketmaker II sites. Their tabulation reveals a dis-
tinct clustering of dates between about A.D. 100
and 300, except in the southernmost site groups
(Chuska/Lukachukai,in northeastern Arizona and
extreme northwestern New Mexico, and Black
Mesa, in northeastern Arizona), in which the cen-
tral tendencies for dates are somewhat earlier. This
suggests that short growing seasons limited farm-
ing expansion to productive northern uplands
throughout much of the first half of the first mil-
lennium A.D. This in turn may have slightly
retarded the expression of the NDT in the South-
west.
It is also possible that the downturn in growth
rates that began about 850 years after the local
introduction of ceramic containers (Figure 4) is
influenced by deteriorating climates. In the Pueblo
area, this decline in 15p5values began around A.D.
1200 in absolute dates. Low-frequency declines in
winter temperature and precipitation began in the
mid-1100s and continued until the late 1300s (tem-
perature) and beyond 1400 for precipitation
(Wright 2006). Meanwhile, high-frequency maize
production conditions in southwestern Colorado,
reconstructed from tree rings (Kohler et al. 2008),
were unfavorable throughout nearly the entire
1200s. We suggest that these trends caused the
“closing of the frontier” for continued expansion
of the farming way of life in the northern South-
west well before its complete depopulation in the
late-A.D. 1200s, with predictable effects on
desired family sizes as excess population became
impossible to export. At the same time, less-
productive conditions throughout the 1200s may
have played an independent role in reducing fer-
tility, at least in those portions of the northern San
Juan where these climatic reconstructions are most
directly applicable.
Population Growth Patterns
Form the Southwestern Region
There appear to be other signals in Figures 3 and
4 of interest to regional specialists. We note, for
example,that the 15p5values tend to decline through
time at Pecos (at the far eastern edge of the Pueblo
world), and that the Gallina subregion of the North-
ern Rio Grande, which lies at the northeastern edge
of the Pueblo world,tends to also have low growth
rates (see the points for NRG950 and NRG1150,
which are composite samples from the Gallina sub-
region). Indeed, some of the highest growth rates,
as proxied by 15p5values, tend to be in regions that
lie toward the center of the Southwest,perhaps sug-
gesting that the reason they were at the center is
that they were able to export population in various
directions. Peripheral areas generally supported
lower growth rates, contributing to their peripher-
ality. This would seem to be almost too obvious to
mention, except that it has not, to our knowledge,
previously been demonstrated.
The second increase in the fitted line, in both
Figures 3 and 4, is not anticipated by the NDT
model itself, though it has a possible analog in the
second bump seen in Figure 4 of Bocquet-Appel
(2002:645) that appears to correspond, in general,
660 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
AQ 73(4) Kohler 10/10/08 10:56 AM Page 660

to Chalcolithic sites with a megalithic aspect, that
are often considered to reflect a more hierarchical
form of sociopolitical organization than present in
the earlier Neolithic sites. In our sample, follow-
ing the logic of the NDT model, the highly aggre-
gated nature of late sites such as Hawikku, San
Cristobal, Grasshopper, and Paquimé would lead
us to anticipate low values for the 15p5measure, but
in fact their values are generally high, and in con-
junction with their large samples, cause the second
increase in our fitted lines. We are not certain what
(if any) economic or social organizational factors
contribute to the apparently high growth rates in
such sites,6but this model throws them into relief
as worthy of explanation. It is also possible that high
rates of migration into these sites, in conjunction
with the process of aggregation and regional demo-
graphic shifts, swamp the signal that the 15p5mea-
sure is designed to measure. This could happen if,
for example, immigrant ages were biased toward
pre-adult years. Alternatively, if the female bias in
immigrant households that Lowell (2007) suggests
for Grasshopper is a general phenomenon related
to sex imbalance in immigrant populations due to
warfare, such biases could in turn soon generate
higher birth rates than would be expected in pop-
ulations of that size with an even sex distribution.
Independent Corroboration
for a late Southwestern NDT
Recently, Kemp (2006) characterized the mito-
chondrial DNA (mtDNA) of 897 individuals from
13 populations in Mesoamerica and the American
Southwest to test for an ancient migration of Uto-
Aztecan speakers from the former region to the lat-
ter, a prediction of the farming/language dispersal
hypothesis (Bellwood 2005; Hill 2001). Surpris-
ingly, few close genetic connections were found
between the two regions and, in particular, Uto-
Aztecan populations in each region were more
closely related to their respective linguistically
unrelated neighbors than they were to each other.
These data should not necessarily cause us to reject
the idea that the Uto-Aztecan language family and
maize agriculture spread northward together, as
suggested by Matson (2002) and Hill (2001), but
they do seem to imply that if this happened, it was
not a major population expansion. Moreover,recent
investigation of Y-chromosome variation exhibited
by some of these same populations—which directly
tracks male prehistory and movement—provides
no support for close genetic connections between
southwestern and Mesoamerican Uto-Aztecan pop-
ulations (Kemp et al. 2008).
Instead, Kemp detected a very clear signature
of an in situ population expansion (a “star-like”
phylogeny; see Kemp 2006:71) in the Southwest.
This expansion was seen specifically in mitochon-
drial haplogroup B, the most common mitochon-
drial haplogroup among present-day populations of
the region, with the highest frequencies occurring
in Pueblo-affiliated populations (“Anasazi” [Car-
lyle et al. 2000], n = 25, 60 percent B; Jemez, n =
71, 86 percent B; Zuni, n = 50, 76 percent B; but
by contrast,e.g.,Akimel O’odham,n = 146, 47 per-
cent B; Aztecs, n = 37, 16 percent B).
In particular, the expansion began from a form
of haplogroup B that exhibits two particular muta-
tions (transitions at positions 16111 and 16483 of
the mitochondrial genome) that today are only
found in the Southwestern populations, and are
conspicuously absent in Mesoamerican popula-
tions. The Cora and Huichol, who exhibit this form
of haplogroup B, are here considered part of the
“Greater Southwest” following Beals (1974). This
was truly a pan-Southwest expansion as all major
linguistic divisions sampled thus far in the region
(Uto-Aztecan, Yuman, Kiowa-Tanoan, and Zuni)
exhibit the expansion type at rather high frequen-
cies (on average 29 percent of all matrilines in the
Southwest are of this type). Kemp (2006) calcu-
lates that the expansion of this clade dates to 2105
BP (99.5 percent CI ± 1,273–3,773 B.P.).7This
confidence interval encompasses the mid-first-
millennium-A.D. date reported here for marked
increase in growth rates accompanying the NDT
in the Southwest.
Since this study by Kemp (2006) was com-
pleted, additional evidence of this expansion has
been detected in populations of Uto-Aztecans and
Yumans from southern California8(Johnson and
Lorenz 2006) as well as in additional Yuman-
speaking populations from the Southwest (Mon-
roe and Kemp 2008). Interestingly, this type is not
found in Yuman-speaking groups residing in Baja
California, suggesting that it occurred after the
major Yuman language families split approximately
1,750–2,500 years ago (Monroe and Kemp 2008),
a date also in accord with the NDT expansion
described here.
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 661
AQ 73(4) Kohler 10/10/08 10:56 AM Page 661

More traditional archaeological data also sug-
gest a late NDT. Dean, Doelle, and Orcutt
(1994:73–76) attempted to make pan-Southwestern
population estimates using data from the archaeo-
logical literature available in the early 1990s. These
measures ultimately depend on site counts and sizes
by phase,and not on ancient human remains or con-
temporary DNA. Their tabulation begins at A.D.
100 and ends at 1600. They reconstruct a rapid
population increase beginning around A.D. 550,
with population peaking around 1000, remaining
high until 1200,and then declining irregularly until
the end of the period they plot. The sharp mid-first
millennium A.D. increase, however, cannot be
taken completely at face value, since as they point
out it is influenced by the first availability of
Hohokam-region population estimates at A.D. 600.
If it were possible to control for that effect, they
suggest, the increase would be more gradual,ramp-
ing up more slowly in the first half of the first-
millennium A.D., but with, likely, a significant
increase remaining at that time.
Conclusions
A Neolithic Demographic Transition is visible in
the U.S. Southwest,but appears much later than the
regional debut of maize slightly before 2000 B.C.,
providing an independent piece of evidence that the
earliest maize supplemented a hunter-gatherer
lifestyle without fundamentally altering it. Some-
what more surprisingly, the NDT also lags the ear-
liest intensive use of maize, measured here by the
appearance of ceramic containers in this region at
ca. A.D. 300, though by a much shorter period.
The Neolithic Demographic Transition,when it
finally arrives, builds on the prior development of
ceramic containers, on the introduction of the bow
and arrow, on recently arrived (or newly devel-
oped) races of maize that help make it possible to
dry-farm many new areas,including extensive and
productive mesa tops in portions of the Northern
San Juan region, and on increasingly permanent
habitations that may facilitate, or reflect, reduc-
tions in interbirth spacing. But before the upland
dry-farming niche can be fully developed,given the
higher risk of dry farming relative to earlier forms
of water-managed maize production,a way of effi-
ciently storing and exchanging agricultural sur-
pluses must be found. The explosive growth in
places like the central Mesa Verde portions of the
Northern San Juan region (Varien et al. 2007) and
its accompanying Pueblo I villages (Wilshusen and
Perry 2008) are the most obvious result, though
less-obvious population growth in other portions
of the Southwest benefiting from dry farming is also
probable. That these early villages appear when
and where they do is logical if, as Kohler and Van
West (1996) argue, such villages make possible for
the first time durable patterns of efficient exchange
of relatively bulky goods such as maize among
non-kin.
Prior to the development of these villages, habi-
tation sites, usually referred to as hamlets, appear
to have been composed of a single kin group that
probably practiced internally a form of generalized
reciprocal exchange. Villages, on the other hand,
contain several hamlet-scale roomblock units. We
infer that exchange among households across
roomblocks was important in the success of these
villages,and that such exchanges would have been
structured through balanced reciprocity. This may
have greatly increased the role of such exchanges
in these societies,ultimately allowing more efficient
allocation of production among all households in
the village, but also providing new opportunities
for ambitious actors to create dependencies (Kohler
et al. 2000:204) and to construct social networks
in which they were quite literally well connected.
Agent-based modeling exercises on virtual land-
scapes resembling those used by these early villages
(Kobti et al. 2006; Kohler et al. 2007) are investi-
gating the effects of various exchange practices on
population size, aggregation, degree of settlement
permanence, storage accumulations, and network
characteristics.
Although the measure of the Neolithic Demo-
graphic Transition developed by Bocquet-Appel
for Europe is not without some problems, it gives
us a new and powerful way of looking directly at
the degree of reproductive success of populations
participating in the new Neolithic (or Formative)
way of life in the U.S. Southwest. This way of life
developed slowly over twenty-five hundred years,
rather than spreading dramatically at the expense
of foragers at its earliest appearance. This view has
been corroborated by the pattern of mitochondrial
variation found in populations of the Southwest
and Mesoamerican, one that provides no evidence
that Mesoamerican farmers came to dominate, at
662 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
AQ 73(4) Kohler 10/10/08 10:56 AM Page 662

least biologically, foragers in the Southwest (Kemp
2006).
Nevertheless, by midway through the first mil-
lennium A.D., a threshold was reached allowing
much more rapid growth. For the next 600 years or
so, southwestern societies explored new sociopo-
litical arrangements allowing them to cope with,
and exploit the competitive advantages of, the larger
group sizes resulting from this growth. A feature
of these periods, known in the Pueblo area as the
Pueblo I and Pueblo II periods, is that their inno-
vations focused more on competitive success of
social groups in this new sociopolitical environ-
ment,and on innovations in obtaining protein from
meat, than they did on innovations in getting more
calories from cultigens. These are, we believe,
among those rare periods in human history where
populations found themselves for a time at least
generally below the carrying capacities of their eco-
nomic systems in their natural environments.
Summary and Afterthoughts
The long dawn of the Formative in the U.S. South-
west reminds us that the line between foraging and
agriculture is not fine and clearly drawn but should
be conceptualized, especially here, as encompass-
ing a diverse set of societies practicing various
degrees of low-level food production or protoagri-
culture (Keeley 1995; Smith 2001b) in a variety of
settings,using different strategies. One usual bench-
mark for agricultural societies—domestication—
was passed very early in much of the Southwest.
As we saw in the first part of this article, though,
archaeologists have held conflicting ideas about
the importance and effects of domesticated plants
in societies predating the late prehistoric periods.
Some of this ambiguity can be resolved, as we
attempt to do here, by considering not just the “sup-
ply” side of the subsistence equation (e.g., domes-
ticated plants constitute n percentof the diet,which
is typically difficult to reconstruct), but also what
we might call the demand side: what are the birth
rates, and growth rates,of the populations in ques-
tion? Specifically,have they undergone a Neolithic
Demographic Transition,as observed in central and
western Europe,and in the Levant,and as predicted
for sedentary agriculturalists? Here we show how
that might be assessed.
Our results, as we interpret them, do not shed
much light on the demographic processes accom-
panying the earliest arrival of maize to the South-
west, though the current absence of populations
suitable for the techniques used here implies that
achieved growth rates were slow at best both prior
to and immediately after its arrival. Furthermore,
current mtDNA results suggest that the demic cor-
relates of this earliest expansion of maize cultiva-
tion were slight or have been blurred by the more
recent population expansion. In making these
observations we acknowledge the possibility that
more demographic and genetic data from popula-
tions predating the appearance of agriculture, and
during the Early Agricultural period, may eventu-
ally reveal modest increases in growth rates in con-
junction with the earliest appearance of maize. We
would be very surprised,however, if these were as
dramatic as the later increases we document here.
We also remind our readers that our samples are
larger in the northern (Puebloan) Southwest, pos-
sibly affecting our conclusions.
As we interpret our results,there is material here
to please and aggravate both the population-
pressure theorist, and the aggrandizer theorist, on
the “origins of agriculture” question. The very slow
achieved growth rates for more than two thousand
years following the introduction of maize to South-
western economies suggest, to us, that populations
were generally near their economically governed
carrying capacities. We suspect that the initial adop-
tion and slowly increased dependence on domes-
ticated species emerged from nothing more
dramatic than people seeking the least-costly means
of meeting their subsistence needs in contexts of
changing climates, environments,and demographic
pressures. The changing environment includes the
genomic changes that domesticated species were
undergoing in response to the selective pressures
of domestication.
It seems probable to us, though, that the NDT
beginning around the mid-first-millennium A.D.
coincides with an increased salience for various
social and political interactions that may have the
effect of allowing or even provoking population
growth. We have suggested above what some of
those might be, but much still remains to be con-
vincingly unraveled. Is the burst of growth due only
to a completely achieved sedentism in these con-
texts, or is there more? And what specifically
allows, or provokes, that sedentism? Though we
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 663
AQ 73(4) Kohler 10/10/08 10:56 AM Page 663

have answered some questions here to our satis-
faction, others remain. We hope they can now be
more clearly poised.
Acknowledgments. An earlier version of this paper was
developed for an extremely stimulating and productive ses-
sion at the Harvard Center for the Environment in December
2006, organized by Jean-Pierre Bocquet-Appel and Ofer
Bar-Yosef. Kohler acknowledges the support of NSF (BCS-
0119981). Many people provided advice or unpublished data
while this paper was being written, including Nancy Akins,
Eric Blinman, Joan Coltrain, Andrew Duff, Patricia Gilman,
Ed Huber,Winston Hurst, Steven Leblanc, John McClelland,
Cara Monroe, Stephan Naji, Scott Ortman,Ann Lucy Weiner
Stodder, Alan Swedlund, Brad Vierra, Carla Van West, Chip
Wills, and Richard Wilshusen. Our apologies if we have for-
gotten anyone—and to anyone whose advice we followed
less than faithfully.
References Cited
Adams, Karen R.
1994 A Regional Synthesis of Zea mays in the Prehistoric
American Southwest. In Corn and Culture in the Prehis-
toric New World, edited by Sissel Johannessen and Chris-
tine A. Hastorf, pp. 273–302. Westview Press, Boulder.
Adams, Karen R., Cathryn M. Meegan, Scott G. Ortman, R.
Emerson Howell, Lindsay C. Werth, Deborah A.
Muenchrath, Michael K. O’Neill,and Candice A. C. Gard-
ner
2006 MAÍS (Maize of Indigenous Societies) Southwest:Ear
Descriptions and Traits that Distinguish 27 Morphologi-
cally Distinct Groups of 123 Historic USDA Maize (Zea
mays L. spp. Mays) Accessions and Data Relevant to
Archaeological Subsistence Models. Manuscript on file
with Karen Adams.
Akins, Nancy J.
2008 Chapter 22: Human Skeletal Remains. In Excava-
tions along NM 22: Agricultural Adaptation from AD 500
to 1900 in the Northern Santo Domingo Basin, Sandoval
County, New Mexico, vol. 2, Major Site Excavations at LA
265,LA 6169, LA 6170, and LA 6171, compiled by Stephen
S. Post and Richard C. Chapman. Archaeology Notes 385.
Office of Archaeological Studies, Museum of New Mex-
ico, Santa Fe. In preparation.
Ammerman,Albert J., and Luigi Luca Cavalli-Sforza
1973 A Population Model for the Diffusion of Early Farm-
ing in Europe. In The Explanation of Culture Change,
edited by Colin Renfrew, pp. 343–357. Duckworth, Lon-
don.
1984 The Neolithic Transition and the Genetics of Popula-
tions in Europe. Princeton University Press, Princeton.
Anyon, Roger, and Steven A. Leblanc
1984 The Galaz Ruin: A Prehistoric Mimbres Village in
Southwestern New Mexico. University of New Mexico
Press, Albuquerque.
Bandy, Matthew S.
2005 New World Settlement Evidence for a Two-Stage
Neolithic Demographic Transition. Current Anthropology
46(S):S109–S115.
2008 Global Patterns of Early Village Development. In The
Neolithic Demographic Transition and its Consequences,
edited by Jean-Pierre Bocquet-Appel and Ofer Bar Yosef.
Springer, Dordrecht, The Netherlands, in press.
Bandy, Matthew S., Stephan Naji, and Jean-Pierre Bocquet-
Appel
2008 Did the Eastern Agricultural Complex Produce a
Neolithic Demographic Transition? In The Neolithic
Demographic Transition and its Consequences, edited by
Jean-Pierre Bocquet-Appel and Ofer Bar-Yosef. Springer,
Dordrecht,The Netherlands, in press.
Barlow, K. Renee
2006 A Formal Model for Predicting Agriculture among the
Fremont. In Behavioral Ecology and the Transition to
Agriculture, edited by Douglass J. Kennett and B. Win-
terhalder, pp. 87–102. University of California Press,
Berkeley.
Beals, Ralph L.
1974 Cultural Relations between Northern Mexico and the
Southwest United States: Ethnologically and Archaeo-
logically. In The Mesoamerican Southwest: Readings in
Archaeology,Ethnohistory,and Ethnology,edited by Basil
C. Hedrick, J. Charles Kelley, and Carroll L. Riley, pp.
52–57. Southern Illinois University Press, Carbondale.
Bellwood,Peter S.
2005 First Farmers: The Origins of Agricultural Societies.
Blackwell Publishing, Malden, Massachusetts.
Bellwood,Peter S., and Colin Renfrew (editors)
2002 Examining the Farming/Language Dispersal Hypoth-
esis. Oxbow Books, Oxford, UK.
Benz, Bruce F.
2006 Maize in the Americas. In Histories of Maize: Multi-
disciplinary Approaches to the Prehistory, Linguisitics,
Biogeography and Evolution of Maize, edited by John
Staller, Robert Tykot, and Bruce Benz,pp. 9–20. Elsevier
Academic Press, Boston.
Blake, Michael
2006 Dating the Initial Spread of Zea mays. In Histories of
Maize: Multidisciplinary Approaches to the Prehistory,
Linguisitics, Biogeography and Evolution of Maize, edited
by John Staller,Robert Tykot,and Bruce Benz,pp. 55–72.
Elsevier Academic Press, Boston.
Bocquet-Appel, Jean-Pierre
2002 Paleoanthropological Traces of a Neolithic Demo-
graphic Transition. Current Anthropology 43:637–650.
2005 La transition démographique néolithique. In Popula-
tions néolithiques et environnements - séminaire du Col-
lège de France, edited by Jean Guilaine, pp. 11–20.
Editions Errance, Paris.
2008 Explaining the Neolithic Demographic Transition
Inferred from Cemetery Data. In The Neolithic Demo-
graphic Transition and its Consequences, edited by Jean-
Pierre Bocquet-Appel and Ofer Bar-Yosef. Springer,
Dordrecht,The Netherlands, in press.
Bocquet-Appel, Jean-Pierre, and Jérome Dubouloz
2003 Traces paléoanthropologiques et archéologiques
d’une transition démographique néolithique en Europe.
Bulletin de la Société Préhistorique Française
100:699–714.
2004 Expected Palaeoanthropological and Archaeological
Signal from a Neolithic Demographic Transition on a
Worldwide Scale. Documenta Praehistorica 31:25–33.
Bocquet-Appel, Jean-Pierre, and Lucienne Jakobi
1998 Evidence for a Spatial Diffusion of Contraception at
the Onset of Fertility Transition in Victorian Britain. Pop-
ulation, An English Selection, special issue of New
Advances in Social Sciences 10:181–204.
Bocquet-Appel, Jean-Pierre, and Stephan Naji
2006 Testing the Hypothesis of a Worldwide Neolithic
Demographic Transition: Corroboration from American
Cemeteries. Current Anthropology 47:341–365.
664 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
AQ 73(4) Kohler 10/10/08 10:56 AM Page 664

Bocquet-Appel, Jean-Pierre, and Mariá Paz de Miguel Ibanez
2002 Demografia de la difusion neolitica en Europa y los
datos paleoanthropologicos. Sagutum 5:23–44.
Bocquet-Appel,Jean-Pierre,S. Irudaya Rajan, Jean Noël Bacro,
and Christian Lajaunie
2002 The Onset of India’s Fertility Transition. European
Journal of Population 18(3):211–232.
Bocquet-Appel, Jean-Pierre, and Ofer Bar-Yosef (editors)
2008 The Neolithic Demographic Transition and its Con-
sequences. Springer-Verlag,Dordrecht, The Netherlands,
in press.
Buzon, Michele R., and Anne L. Grauer
2002 A Bioarchaeological Analysis of Subsistence Strate-
gies at the SU Site, New Mexico. Kiva 68:103–122.
Carlyle,Shawn W., Ryan L. Parr,M. Geoffrey Hayes,and Den-
nis H. O’Rourke
2000 Context of Maternal Lineages in the Greater South-
west. American Journal of Physical Anthropology
113:85–101.
Charles, Mona C.
2007 Bioarchaeology of the Human Remains Recovered
from the Darkmold Site, 5P4991, a Basketmaker II Site
near Durango, Colorado. Paper presented at the Colorado
Council of Professional Archaeologists,Annual Meeting,
Glenwood Springs, Colorado.
Charles, Mona C. (editor)
2000 The Emergency Excavation of Eleven Human Buri-
als from Archaeological Site 5LP4991,the Darkmold Site,
La Plata County, Colorado. Report on file, Colorado His-
torical Society, Denver.
Charles, Mona C., and Sally J. Cole
2006 Chronology and Cultural Variation in Basketmaker II.
Kiva 72:167–216.
Chisholm, Brian, and R. G. Matson
1994 Carbon and Nitrogen Isotopic Evidence on Basket-
maker II Diet at Cedar Mesa, Utah. Kiva 60:239–256.
Clarke, John E., and Michael Blake
1994 The Power of Prestige: Competitive Generosity and
the Emergence of Rank Society in Lowland Mesoamer-
ica. In Factional Competition and Political Development
in the New World, edited by Elizabeth M. Brumfiel and
John W. Fox, pp. 17–30. Cambridge University Press,
Cambridge.
Cleveland, William S., and Eric Grosse
1991 Computational Methods for Local Regression. Sta-
tistics and Computing 1:47–62.
Coltrain,Joan Brenner, Joel C. Janetski,and Shawn W. Carlyle
2007 The Stable- and Radio-isotope Chemistry of Western
Basketmaker Burials:Implications for Early Puebloan Diet
and Origins. American Antiquity 72:301–321.
Cowan, Jason A., Timothy A. Kohler, C. David Johnson, and
Kevin D. Cooper
2006 Supply,Demand,Return Rates,and Resource Depres-
sion: Hunting in the Village Ecodynamics World. In
Archaeological Simulation: Into the 21st Century, edited
by André Costopoulos. Submitted to University of Utah
Press, Salt Lake City.
Cowgill, George L.
1975 On Causes and Consequences of Ancient and Mod-
ern Population Changes. American Anthropologist
77:505–525.
Crown, Patricia L., and W. H. Wills
1995 Economic Intensification and the Origins of Ceramic
Containers in the American Southwest. In The Emergence
of Pottery:Technology and Innovation in Ancient Societies,
edited by William K. Barnett and John W. Hoopes, pp.
241–254. Smithsonian Institution Press,Washington, D.C.
Damp, Jonathan E., Stephen A. Hall, and Susan J. Smith
2002 Early Irrigation on the Colorado Plateau near Zuni
Pueblo, New Mexico. American Antiquity 67:665–676.
Dean, Jeffrey S.,William H. Doelle, and Janet D. Orcutt
1994 Adaptive Stress, Environment, and Demography. In
Themes in Southwestern Prehistory, edited by George G.
Gumerman, pp. 53–86. School of American Research
Press, Santa Fe.
Diehl, Michael W.
2005 Morphological Observations on Recently Recovered
Early Agricultural Period Maize Cob Fragments from
Southern Arizona. American Antiquity 70:361–375.
Diehl, Michael, and Jennifer A. Waters
2006 Aspects of Optimization and Risk during the Early
Agricultural Period in Southeastern Arizona. In Behavioral
Ecology and the Transition to Agriculture, edited by Dou-
glas J. Kennett and Bruce Winterhalder, pp. 63–86. Uni-
versity of California Press, Berkeley.
Doolittle,William E., and Jonathan B. Mabry
2006 Environmental Mosaics, Agricultural Diversity, and
the Evolutionary Adaptation of Maize in the American
Southwest. In Histories of Maize: Multidisciplinary
Approaches to the Prehistory, Linguistics, Biogeography
and Evolution of Maize, edited by John Staller, Robert
Tykot and Bruce Benz, pp. 109–121. Elsevier Academic
Press, Boston.
Geib, Phil R., and Kimberly Spurr
2002 The Forager to Farmer Transition on the Rainbow
Plateau. In Traditions, Transitions, and Technologies:
Themes in Southwestern Archaeology, edited by Sarah
Schlanger, pp. 224–244. University Press of Colorado,
Boulder.
Gilman, Patricia A.
1987 Architecture as Artifact:Pit Structures and Pueblos in
the American Southwest. American Antiquity 52:538–564.
Guerrero, Emma,Stephan Naji,and Jean-Pierre Bocquet-Appel
2008 The Signal of the Neolithic Demographic Transition
in the Levant. In The Neolithic Demographic Transition
and its Consequences, edited by Jean-Pierre Bocquet-
Appel and Ofer Bar-Yosef. Springer Verlag,Dordrecht,The
Netherlands, in press.
Gumerman, George J., and Jeffrey S. Dean
1989 Prehistoric Cooperation and Competition in the west-
ern Anasazi Area. In Dynamics of Southwest Prehistory,
edited by Linda S. Cordell and George. J. Gumerman, pp.
99–137. Smithsonian Institution Press,Washington,D.C.
Harlan, Jack R.
2006 Indigenous African Agriculture. In The Origins of
Agriculture: An International Perspective, edited by C.
Wesley Cowan and Patty J. Watson,pp. 59–70. University
of Alabama Press,Tuscaloosa.
Hayes,Alden C.
1981 Contributions to Gran Quivira Archeology, Gran
Quivira National Monument, New Mexico. National Park
Service Publications in Archaeology 17,Washington,D.C.
Herrmann, Nicholas P.
1993 Burial Descriptions. In Across the Colorado Plateau:
Anthropological Studies for the Transwestern Pipeline
Expansion Project:Volume 18:Human Remains and Bur-
ial Goods, edited by Nicholas P. Herrmann, Marsha D.
Ogilvie, Charles E. Hilton, and Kenneth L. Brown, pp.
11–32. Maxwell Museum of Anthropology,University of
New Mexico, Albuquerque.
Hill, Jane H.
2001 Proto-Uto-Aztecan: A Community of Cultivators in
Central Mexico? American Anthropologist 103:913–934.
Ho, Simon Y. W., Matthew J. Phillips,Alan Cooper, and Alexei
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 665
AQ 73(4) Kohler 10/10/08 10:56 AM Page 665

J. Drummond
2005 Time Dependency of Molecular Rate Estimates and
Systematic Overestimation of Recent Divergence Times.
Molecular Biology & Evolution 22:1561–1568.
Howell,Neil, Christy Bogolin Smejkal,D.A. Mackey,P.F. Cin-
nery, D. M. Turnbull, Corinna Herrnstadt
2002 The Pedigree Rate of Sequence Divergence in the
Human Mitochondrial Genome: There Is a Difference
between Phylogenetic and Pedigree Rates. American Jour-
nal of Human Genetics 72:659–670.
Huber, Edgar K.
2005 Early Maize at the Old Corn Site (LA 137258). In
Archaeological Data Recovery in the New Mexico Trans-
portation Corridor and First Five-Year Permit Area, Fence
Lake Coal Mine Project, Catron County, New Mexico:
Volume 4: Synthetic Studies and Summary,edited by Edgar
K. Huber and Carla R. Van West, pp. 36.1–36.33. Techni-
cal Series 84. Statistical Research, Inc., Tucson.
Huckell, Bruce B.
1995 Of Maize and Marshes:Preceramic Agricultural Set-
tlements in the Cienega Valley, Southeastern Arizona.
Anthropological Papers of the University of Arizona 59.
University of Arizona Press, Tucson.
Huckell, Bruce B., Lisa W. Huckell, and Suzanne K. Fish
1995 Investigations at Milagro, a Late Preceramic Site in
the Eastern Tucson Basin. Technical Report 94-5. Center
for Desert Archaeology,Tucson.
2002 Maize Agriculture and the Rise of Mixed Farming-
Foraging Economies in Southeastern Arizona During the
Second Millenium B.C. In Traditions, Transitions, and
Technologies: Themes in Southwestern Archaeology,
edited by Sarah Schlanger, pp. 137–159. University Press
of Colorado, Boulder.
Huckell, Lisa W.
2006 Ancient Maize in the Southwest:What Does it Look
Like and What Can It Tell Us? In Histories of Maize: Mul-
tidisciplinary Approaches to the Prehistory, Linguisitics,
Biogeography and Evolution of Maize, edited by John
Staller, Robert Tykot, and Bruce Benz, pp. 97–107. Else-
vier Academic Press, Boston.
Hurvich, Clifford M., Jeffrey S. Simonoff, and Chin-Ling Tsai
1998 Smoothing Parameter Selection in Nonparametric
Regression Using an Improved Akaike Information Cri-
terion. Journal of the Royal Statistical Society B
60:271–293.
Iltis, Hugh H.
2006 Origin of Polystichy in Maize. In Histories of Maize:
Multidisciplinary Approaches to the Prehistory, Linguis-
tics,Biogeography and Evolution of Maize,edited by John
Staller, Robert Tykot, and Bruce Benz, pp. 21–53. Else-
vier Academic Press, Boston.
Johansson, S. Ryan, and Sheryl Horowitz
1986 Estimating Mortality in Skeletal Populations: Influ-
ence of the Growth Rate on the Interpretation of Levels
and Trends during the Transition to Agriculture. American
Journal of Physical Anthropology 71:233–250.
Johnson, John R., and Joseph G. Lorenz
2006 Genetics,Linguistics,and Prehistoric Migrations:An
Analysis of California Indian Mitochondrial DNA Lin-
eages. Journal of California and Great Basin Anthropol-
ogy 26(1):31–62.
Kearns,Timothy M., Chris A. Kugler, and Paul Stirniman
1998 The Dog Leg Site (LA 6448):A Basketmaker II Cache
Locale in the Southern Chuska Valley, New Mexico. In
Pipeline Archaeology 1990–1993: The El Paso Natural
Gas North System Expansion Project,New Mexico and Ari-
zona: Volume 2: Archaic, Basketmaker II, Protohistoric,
and Aceramic Sites in Northwest New Mexico, edited by
T. G. Baugh, T. M. Kearns, and C.W. Wheeler. Western
Cultural Resource Management Inc, Farmington.
Keeley, Lawrence H.
1995 Protoagricultural Practices among Hunter-Gatherers:
A Cross-Cultural Survey. In Last Hunters-First Farmers:
New Perspectives on the Prehistoric Transition to Agri-
culture, edited by T. Douglas Price and Anne Birgitte
Gebauer, pp. 243–272. School of American Research
Press, Santa Fe.
Kemp, Brian M.
2006 Chapter 2:Mitochondrial DNA Variation in the Amer-
ican Southwest and Mesoamerica. In Mesoamerica and
Southwest prehistory, and the Entrance of Humans into
the Americas:Mitochondrial DNA Evidence. Unpublished
Ph.D. dissertation, Department of Anthropology, Univer-
sity of California, Davis.
Kemp,Brian M.,Angelica Gonzalez-Oliver,Kari B. Schroeder,
David Glenn Smith,Andres Resendez,and Ripan S. Malhi
2008 Brief Communication:Male-mediated Gene Flow in
Mesoamerica and the American Southwest. Manuscript
submitted to American Journal of Physical Anthropology.
Kemp,Brian M., Ripan S. Malhi, John McDonough, Deborah.
A. Bolnick, Jason A. Eshleman, Olga Rickards, Christina
Martinez-Labarga,John R. Johnson,Joseph G. Lorenz, E.
James Dixon, Terrence E. Fifield, Timothy H. Heaton,
Rostia Worl, and David G. Smith
2007 Genetic Analysis of Early Holocene Skeletal Remains
from Alaska and Its Implications for the Settlement of the
Americas. American Journal of Physical Anthropology
132: 605–621.
Kobti, Ziad, Robert G. Reynolds, and Timothy A. Kohler
2006 The Emergence of Social Network Hierarchy Using
Cultural Algorithms. International Journal on Artificial
Intelligence Tools 15:963–978.
Kohler, Timothy A.
1993 News from the Northern American Southwest: Pre-
history on the Edge of Chaos. Journal of Archaeological
Research 1:267–321.
Kohler, Timothy A., Sarah Herr, and Matthew J. Root
2004 The Rise and Fall of Towns on the Pajarito (A.D.
1375–1600). In The Archaeology of Bandelier National
Monument: Village Formation on the Pajarito Plateau,
New Mexico, edited by Timothy A. Kohler, pp. 215–264.
University of New Mexico Press, Albuquerque.
Kohler, Timothy A.,C. David Johnson,Mark Varien, Scott Ort-
man,Robert Reynolds,Ziad Kobti,Jason Cowan,Kenneth
Kolm, Schaun Smith, and Lorene Yap
2007 Settlement Ecodynamics in the Prehispanic Central
Mesa Verde Region. In The Model-Based Archaeology of
Socionatural Systems, edited by Timothy A. Kohler and
Sander van der Leeuw, pp. 61–104. SAR Press, Santa Fe.
Kohler, Timothy A., and Kathryn Kramer Turner
2006 Raiding for Women in the Prehispanic Northern
Pueblo Southwest? A Pilot Examination. Current Anthro-
pology 47:1035–1045.
Kohler,Timothy A.,Matthew W. Van Pelt,and Lorene Y. L. Yap
2000 Reciprocity and its Limits: Considerations for a Study
of the Prehispanic Pueblo World. In Alternative Leader-
ship Strategies in the Prehispanic Southwest,edited by Bar-
bara J. Mills, pp. 180–206. University of Arizona Press,
Tucson.
Kohler, Timothy A., and Carla Van West
1996 The Calculus of Self Interest in the Development of
Cooperation:Sociopolitical Development and Risk among
the Northern Anasazi. In Evolving Complexity and Envi-
ronmental Risk in the Prehistoric Southwest, edited by
666 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
AQ 73(4) Kohler 10/10/08 10:56 AM Page 666

Joseph A. and Bonnie Bagley Tainter, pp. 169–196. Santa
Fe Institute Studies in the Sciences of Complexity, Pro-
ceedings Vol. XXIV. Addison-Wesley, Reading, Massa-
chusetts.
Kohler, Timothy A., and Mark D. Varien
2009 Model-Based Perspectives on 700 Years of Farming
Settlements in Southwest Colorado. In Becoming Villagers,
edited by Matthew S. Bandy and Jake R. Fox. Submitted
to the University of Arizona Press, Tucson.
Kohler,Timothy A.,Mark D. Varien,Aaron Wright,and Kristin
A. Kuckelman
2008 Mesa Verde Migrations. American Scientist
96:146–153.
Kramer, Kathryn
2002 Sex Ratios and Warfare in the Prehistoric Puebloan
Southwest. Unpublished M.A. Thesis, Department of
Anthropology, Washington State University, Pullman.
Lipe, William D.
1999 Basketmaker II (1000 B.C. – A.D. 500). In Colorado
Prehistory: A Context for the Southern Colorado River
Basin, edited by William D. Lipe, Mark D. Varien, and
Richard H. Wilshusen, pp. 132–165. Colorado Council of
Professional Archaeologists, Denver.
Lowell, Julia C.
2007 Women and Men in Warfare and Migration:Implica-
tions of Gender Imbalance in the Grasshopper Region of
Arizona. American Antiquity 72:95–123.
Mabry, Jonathan B.
1998 Archaeological Investigations at Early Village Sites
in the Middle Santa Cruz Valley: Analyses and Synthesis.
Anthropological Papers 19. Center for Desert Archaeol-
ogy,Tucson.
1999 Las Capas and Early Irrigation Farming. Archaeology
Southwest 13:14.
McCaa, Robert
2000 The Peopling of Mexico from Origins to Revolution.
In A Population History of North America, edited by
Michael R. Haines and Richard H. Steckel, pp. 241–304.
Cambridge University Press, New York.
McClelland, John
2005 Bioarchaeological Analysis of Early Agricultural
Period Human Skeletal Remains from Southern Arizona.
In Subsistence and Resource Use Strategies of Early Agri-
cultural Communities in Southern Arizona, edited by
Michael W. Diehl, pp. 153–168. Anthropological Papers
No. 34, Center for Desert Archaeology, Tucson.
2008 Health and Demography of Early Agriculturalists in
Southern Arizona. In Reanalysis and Reinterpretation in
Southwestern Bioarchaeology, edited by Ann Lucy Stod-
der, pp. 83–104. Anthropological Papers No. 59, Arizona
State University, Tempe.
Martin, Debra L., and Nancy Akins
2001 Unequal Treatment in Life as in Death: Trauma and
Mortuary Behavior at La Plata (A.D. 1000–1300). In
Ancient Burial Practices in the American Southwest:
Archaeology,Physical Anthropology and Native American
Perspectives, edited by Douglas R. Mitchell and Judy L.
Brunson-Hadley, pp. 223–248. University of New Mex-
ico Press,Albuquerque.
Martin,Debra L.,Alan H. Goodman,George J. Armelagos,and
Ann L. Magennis
1991 Black Mesa Anasazi Health:Reconstructing Life from
Patterns of Death and Disease. Centre for Archaeological
Investigations,Occasional Paper No. 14. Southern Illinois
University at Carbondale, Carbondale.
Matson, R. G.
1991 The Origins of Southwestern Agriculture. University
of Arizona Press,Tucson.
2002 The Spread of Maize Agriculture into the U.S. South-
west. In Examining the Farming/Language Dispersal
Hypothesis, edited by Peter Bellwood and Colin Renfrew,
pp. 341–356. McDonald Institute Monographs,University
of Cambridge, Cambridge, UK.
Matson, R. G., and Brian Chisholm
1991 Basketmaker II Subsistence: Carbon Isotopes and
Other Dietary Indicators from Cedar Mesa, Utah. Ameri-
can Antiquity 56:444–459.
Mobley, Charles M.
1980 Demographic Structure of Pecos Indians: A Model
Based on Life Tables. American Antiquity 45:518–530.
Monroe, Cara, and Brian M. Kemp
2008 Mitochondrial DNA Analysis Provides Evidence for
an Ancient Southwest Population Expansion. Paper pre-
sented at the 73rd Annual Meeting of the Society for Amer-
ican Archaeology, Vancouver, B.C.
Neily, Robert B.
1982 Basketmaker Settlement and Subsistence along the
San Juan River, Utah: The U.S. 163 Archaeological Pro-
ject. Report on file, Utah Department of Transportation,
Salt Lake City.
Pearsall, Deborah M.
2006 The Origins of Plant Cultivation in South America.
In The Origins of Agriculture: An International Perspec-
tive, edited by C. Wesley Cowan and Patty Jo Watson,pp.
173–205. University of Alabama Press,Tuscaloosa.
Ravesloot, John C., and Marcia H. Regan
2000 Demographic, Health, Genetic, and Mortuary Char-
acteristics of Late Prehistoric Central Arizona Populations.
In Salado, edited by Jeffrey S. Dean, pp. 28–57. Univer-
sity of Mexico Press,Albuquerque.
Renfrew, Colin
1987 Archaeology and Language: The Puzzle of Indo-
European Origins. J. Cape, London.
Rowen, Edward J., III
1980 Human Skeletal Remains. In The Durango South Pro-
ject: Archaeological Salvage of Two Late Basketmaker III
Sites in the Durango District,edited by John D. Gooding,
pp. 159–175. Anthropological Papers of the University of
Arizona 34. University of Arizona Press, Tucson.
Sattenspiel, Lisa, and Henry Harpending
1983 Stable Populations and Skeletal Age. American Antiq-
uity 48:489–498.
Schurr, Mark R., and David L. Gregory
2002 Fluoride Dating of Faunal Materials by Ion-selective
Electrode: High Resolution Relative Dating at an Early
Agricultural Period Site in the Tucson Basin. American
Antiquity 67:281–299.
Sheridan, Susan G.
2001 Morbidity and Mortality in a Classic-Period Hohokam
Community. In Ancient Burial Practices in the American
Southwest: Archaeology, Physical Anthropology and
Native American Perspectives, edited by Douglas R.
Mitchell and Judy L. Brunson-Hadley,pp. 191–222. Uni-
versity of New Mexico Press,Albuquerque.
Simmons,Alan H.
1986 New Evidence for the Early Use of Cultigens in the
American Southwest. American Antiquity 51:73–88.
Smiley, Francis E.
1994 The Agricultural Transition in the Northern South-
west: Patterns in the Current Chronometric Data. Kiva
60:165–189.
Smith, Bruce D.
2001a Documenting Plant Domestication:The Consilience
of Biological and Archaeological Approaches. Proceed-
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 667
AQ 73(4) Kohler 10/10/08 10:56 AM Page 667

ings of the National Academy of Sciences
98(4):1324–1326.
2001b Low-Level Food Production. Journal of Archaeo-
logical Research 9:1–43.
Stodder, Ann Lucy Weiner
1994 Bioarchaeological Investigation of Protohistoric
Pueblo Health and Demography. In In the Wake of Con-
tact: Biological Responses to Conquest, edited by Clark
Spencer Larsen and George R. Milner,pp. 97–107. Wiley-
Liss, New York.
Swedlund,Alan C.
1969 Human Skeletal Material from the Yellowjacket
Canyon Area, Southwestern Colorado. Unpublished M.A.
Thesis, Department of Anthropology, University of Col-
orado, Boulder.
Valeggia, Claudia, and Peter T. Ellison
2004 Lactational Amenorrhoea in Well-Nourished Toba
women of Formosa, Argentina. Journal of Biosocial Sci-
ence 36:573–595.
Varien, Mark D., Scott G. Ortman, Timothy A. Kohler, Donna
M. Glowacki, and C. David Johnson
2007 Historical Ecology in the Mesa Verde Region:Results
from the Village Project. American Antiquity72:273–299.
Vierra, Bradley J., and Richard I. Ford
2006 Early Maize Agriculture in the Northern Rio Grande
Valley, New Mexico. In Histories of Maize: Multidisci-
plinary Approaches to the Prehistory, Linguistics, Bio-
geography and Evolution of Maize,edited by John Staller,
Robert Tykot,and Bruce Benz,pp. 497–510. Elsevier Aca-
demic Press, Boston.
Warrick, Gary
2006 Comment On:Testing the Hypothesis of a Worldwide
Neolithic Demographic Transition: Corroboration from
American Cemeteries. Current Anthropology 47:355.
Weiss, Kenneth M.
1973 Demographic Models for Anthropology. Memoirs of
the Society for American Archaeology 27. Washington,
D.C.
Willey, Gordon R., and Philip Phillips
1958 Method and Theory in American Archaeology. Uni-
versity of Chicago Press, Chicago.
Wills,W. H.
1988 Early Agriculture and Sedentism in the American
Southwest: Evidence and Interpretations. Journal of World
Prehistory 2:445–488.
1992 Plant Cultivation and the Evolution of Risk-Prone
Economies in the Prehistoric American Southwest. In
Transitions to Agriculture in Prehistory, edited by Anne
Birgitte Gebauer and T. Douglas Price, pp. 153–176.
Monographs in World ArchaeologyNo. 4. Prehistory Press,
Ann Arbor.
Wilshusen, Richard H.
1999a Basketmaker III (A.D. 500–750). In Colorado Pre-
history:A Context for the Southern Colorado River Basin,
edited by William D. Lipe, Mark D. Varien, and Richard
H. Wilshusen, pp. 166–195. Colorado Council of Profes-
sional Archaeologists, Denver.
1999b Pueblo I (A.D. 750–900). In Colorado Prehistory:
A Context for the Southern Colorado River Basin, edited
by William D. Lipe, Mark D. Varien, and Richard H.
Wilshusen,pp. 196–241. Colorado Council of Professional
Archaeologists, Denver.
Wilshusen, Richard H., and Elizabeth M. Perry
2006 Evaluating the Emergence of Early Villages in the
North American Southwest in Light of the Proposed
Neolithic Demographic Transition. Draft for Conference
“The Neolithic Demographic Transition and its Conse-
quences,” 8–10 December, Harvard Center for the Envi-
ronment, Cambridge.
Wright,Aaron M.
2006 A Low-Frequency Paleoclimatic Reconstruction from
the La Plata Mountains,Colorado and its Implications for
Agricultural Productivity in the Mesa Verde Region.
Unpublished M.A. Thesis, Department of Anthropology,
Washington State University, Pullman.
Zvelebil, Marek
2000 The Social Context of Agricultural Transition in
Europe. In Archaeogenetics:DNA and the Population Pre-
history of Europe, edited by Colin Renfrew and Kather-
ine Boyle, pp. 57–59. McDonald Institute for
Archaeological Research,Cambridge.
Notes
1. All dates in this paper are either general dates, tree-
ring-based dates, or calibrated 14C ages.
2. We made chronological subdivisions within aggregated
assemblages reported by Bocquet-Appel and Naji (2006:349)
for Black Mesa and Pecos Pueblo, and we did not use their
data for Mesa Verde and Pueblo Bonito, since these were
included in more chronologically precise fashion in the data
compiled by Kramer.
3. Those who prefer an absolute chronology can see the
Pueblo sites (only) in this analysis graphed against their
absolute ages in Kohler and Varien (2009). As the areas con-
sidered become smaller, and the dates for earliest maize and
ceramics subject to less spatial lag, absolute chronologies
become more acceptable for our purposes.
4. SAS v. 9.1.3, PROC LOESS. Loess is fundamentally a
nonparametric method for fitting a regression relationship to
noisy data that frequently exhibit nonlinear relationships.
Nevertheless statistical inference is possible. Following pro-
cedures outlined in Cleveland and Grosse (1991), we can
compare the goodness-of-fit of the line in Figure 3, formed
using a smoothing parameter of 0.56, against the straight line
that would be fitted using all the points simultaneously (i.e., a
smoothing parameter of 1.0). This comparison yields an
F(2.4,45.2) = 3.36,p= .035, indicating that the loess line we dis-
play is a significantly better fit than the straight-line fit would
be. Using the same procedures for the loess line in Figure 4,
we calculate F(3.1,44) = 4.37, p= .0004, indicating that the
loess line we display is a significantly better fit than the
straight-line fit would be. Since the sample size is constant
across the analyses in these two figures, we have also
improved the fit relative to the loess line in Figure 3 by chang-
ing the calculation of the years dt.
5. This assumes that deaths due to warfare are slightly
more likely in the ≥20-year-old group, that individuals dying
from warfare were as likely to enter the excavated death
assemblages as were individuals dying from other causes, and
that individuals dying from warfare in each age category were
equally likely to enter the excavated death assemblages.
6. Though we have some suspicions. Kohler et al. (2004)
have pointed to the proto-market forces visible in Classic
period (mid-fourteenth- through early sixteenth-century)
towns in the Northern Rio Grande and suggested that this
vibrant new economic organization, which is accompanied by
novel forms of ceremonial organization, contributed signifi-
668 AMERICAN ANTIQUITY [Vol. 73, No. 4, 2008
AQ 73(4) Kohler 10/10/08 10:56 AM Page 668

cantly to the success of these large aggregates.
7. This range of dates would not go uncontested by some
molecular anthropologists. It is based on a mutation rate
derived from pedigree studies (Howell et al. 2003), which has
recently been argued by Kemp et al. (2007) to extend further
back in time than previously believed. The independent data
derived here from the archaeological record provide more
evidence that previous estimates of mtDNA evolution are too
slow (Kemp et al. 2007; Ho et al. 2005).
8. The Uto-Aztecan and Yuman populations of southern
California, argued here to exhibit a signature of the hap-
logroup B expansion, all exhibit a mutation at position 16111
of the mitochondrial genome, in common with those individ-
uals in the Southwest characterized by Kemp (2006).
However, the other position (i.e., 16483) found in the expan-
sion type of haplogroup B in the Southwest was unfortunately
not screened by Johnson and Lorenz (2006). It is very likely
that these individuals also exhibited a mutation at the 16483
position.
Received May 31, 2007; Accepted December 12, 2007.
Kohler et al.] THE NEOLITHIC DEMOGRAPHIC TRANSITION IN THE U.S. SOUTHWEST 669
AQ 73(4) Kohler 10/10/08 10:56 AM Page 669