Research ArticleANTHROPOLOGY

Exploration and exploitation in the macrohistory of the pre-Hispanic Pueblo Southwest

See allHide authors and affiliations

Science Advances  01 Apr 2016:
Vol. 2, no. 4, e1501532
DOI: 10.1126/sciadv.1501532
  • Fig. 1 The rain-fed maize growing niche in the southwestern United States, A.D. 500–1400.

    Each cell is colored by the percentage of years it is in the niche; darker green represents more years in the niche. Black dots mark the locations of tree-ring–dated sites in our database (n = 1002). Our study area is within the dotted rectangle encompassing all these sites. UT, Utah; AZ, Arizona; CO, Colorado; NM, New Mexico.

  • Fig. 2 Tree-ring date distributions and the percentage of the landscape in the rain-fed MFN where and when tree-ring dates are found, A.D. 500–1400.

    Pecos period divisions (dashed lines) and subperiod divisions (dotted lines) as rederived here are superimposed on all plots. All series are smoothed using a 21-year center-aligned Gaussian filter with a 5-year SD. (A) Stacked histogram of the number of cutting and noncutting dates through time. (B) Stacked histogram of the number of 30–arc sec cells with dates, shaded by the percentage of cutting dates in the cell. Red indicates cells with 100% cutting or near-cutting dates; blue indicates cells with 0% cutting or near-cutting dates. (C) The percentage in the niche of all 30–arc sec cells (solid black line), of all cells that ever contain tree-ring dates (dotted black line), and all local cells with 95% confidence intervals (CIs) (white line with colored bars). A local cell has a tree-ring date in the plotted year or any of the previous 3 years. The color of the confidence interval for each year indicates the unsmoothed mean of the percentages of dates in each cell that are cutting and near-cutting; the color ramp is as in (B). (D) The domain radius, or radius of maximal clustering, through time (see Materials and Methods). The black line connects true data points estimated annually; the red line is smoothed as above. Lower values indicate more dispersion between smaller clusters of occupied cells, whereas higher values indicate spatially larger clusters of occupied cells. The red line is missing in periods of no significant clustering.

  • Fig. 3 Average prediction error across space and through time for each climate reconstruction, A.D. 500–1400.

    In each map, lighter (lower) values indicate a higher-quality reconstruction for that place. Declines or increases in error through time (B and D) occur when particularly important tree-ring chronologies for reconstructing each climate signal become available or unavailable, respectively. (A) Water-year precipitation, averaged through time. (B) Water-year precipitation, averaged across space. (C) Growing-season GDD, averaged through time. (D) Growing-season GDD, averaged across space.

  • Fig. 4 Monte Carlo resampling of tree-ring date distributions controlling sample-size disparities between sites (n = 1002), A.D. 500–1400.

    These are based on 999 replications; each replication represents a randomly selected date (cutting or noncutting) drawn from each site in the database. Pecos period divisions (dashed lines) and subperiod divisions (dotted lines) as rederived here are superimposed on all plots. All series are smoothed using a 21-year center-aligned Gaussian filter with a 5-year SD. (A) Mean number of dates through time, ±1 SD. (B) Stacked plot of the mean number of 30–arc sec cells with dates, shaded by the percentage of cutting dates in the cell. Red indicates cells with 100% cutting or near-cutting dates; blue indicates cells with 0% cutting or near-cutting dates.

  • Fig. 5 For each Pecos classification subperiod, the mean number of years, within a 4-year window ending in the current year, for which a cell is in the MFN.

    Pecos period divisions (dashed lines) and subperiod divisions (dotted lines) as rederived here are superimposed on all plots. Points represent the mean; error bars show ±1 SD.

  • Fig. 6

    The rain-fed MFN and tree-ring dates by revised Pecos subperiod. In each panel, the green shading represents the percentage of years in that period that each 30–arc sec cell is in the MFN; darker greens reflect more years in the niche. Dots represent cells with tree-ring dates in each subperiod, shaded by the percentage of cutting dates in the cell. Red indicates cells with 100% cutting or near-cutting dates; blue indicates cells with 0% cutting or near-cutting dates. The region is as defined in Fig. 1.

  • Fig. 7 Histogram of the distribution of tree-ring date counts across archaeological sites.

    Most sites in the database only have a single tree-ring date, whereas several sites have hundreds of dates. The y axis is logarithmic.

  • Table 1 Summary statistics for each subperiod. The “MFN” measures are the percentage of cells in the niche as in Fig. 2C.
    ExplorationExploitation
    BM IIIYears A.D.500–600Years A.D.600–700
    Cutting count, n (%)80 (9.3)Cutting count, n (%)1012 (45.8)
    Noncutting count, n (%)782 (90.7)Noncutting count, n (%)1198 (54.2)
    MFN—all (%)49.1MFN—all (%)47.2
    MFN—cells with dates (%)65.6MFN—cells with dates (%)66.6
    MFN—local (%)74.8MFN—local (%)68.5
    P IYears A.D.700–790Years A.D.790–890
    Cutting count, n (%)441 (34.9)Cutting count, n (%)1402 (48.9)
    Noncutting count, n (%)822 (65.1)Noncutting count, n (%)1466 (51.1)
    MFN—all (%)43.5MFN—all (%)44.7
    MFN—cells with dates (%)63.0MFN—cells with dates (%)63.8
    MFN—local (%)70.2MFN—local (%)71.2
    P IIYears A.D.890–1035Years A.D.1035–1145
    Cutting count, n (%)836 (25.3)Cutting count, n (%)3740 (53.7)
    Noncutting count, n (%)2470 (74.7)Noncutting count, n (%)3223 (46.3)
    MFN—all (%)43.7MFN—all (%)49.8
    MFN—cells with dates (%)61.3MFN—cells with dates (%)65.8
    MFN—local (%)64.9MFN—local (%)64.7
    P IIIYears A.D.1145–1200Years A.D.1200–1285
    Cutting count, n (%)582 (34.7)Cutting count, n (%)4523 (61.2)
    Noncutting count, n (%)1096 (65.3)Noncutting count, n (%)2864 (38.8)
    MFN—all (%)46.9MFN—all (%)46.4
    MFN—cells with dates (%)63.4MFN—cells with dates (%)61.7
    MFN—local (%)61.7MFN—local (%)62.4
    P IVYears A.D.1285–1400
    Cutting count, n (%)1534 (55.3)
    Noncutting count, n (%)1238 (44.7)
    MFN—all (%)52.1
    MFN—cells with dates (%)70.0
    MFN—local (%)66.3
  • Table 2 Summary statistics calculated from the count of years in the current and previous 3 years in which cells with tree-ring dates are in the MFN.

    Calculations for cells with dates reflect the MFN status for each subperiod of all cells for which any tree-ring date between A.D. 500 and 1400 is present. Calculations for local cells are based on only those cells with tree-ring dates in a given year or any of the previous 3 years. Period boundaries are as given in the text and in Table 1. x̄ is the mean, σ is the SD, G1 is an unbiased estimator of skewness, and G2 is an unbiased estimator of kurtosis. See also Fig. 5.

    ExplorationExploitation
    Cells with
    dates
    Local cellsCells with
    dates
    Local cells
    BM IIIx̄ (σ)2.63 (1.39)x̄ (σ)3.16 (1.11)x̄ (σ)2.66 (1.40)x̄ (σ)2.85 (1.37)
    G1−0.64G1−1.24G1−0.69G1−0.94
    G2−0.88G20.68G2−0.85G2−0.45
    P Ix̄ (σ)2.54 (1.47)x̄ (σ)2.87 (1.35)x̄ (σ)2.54 (1.45)x̄ (σ)2.94 (1.29)
    G1−0.55G1−0.99G1−0.55G1−1.03
    G2−1.12G2−0.30G2−1.10G2−0.12
    P IIx̄ (σ)2.47 (1.44)x̄ (σ)2.73 (1.28)x̄ (σ)2.61 (1.42)x̄ (σ)2.69 (1.37)
    G1−0.48G1−0.71G1−0.64G1−0.70
    G2−1.12G2−0.60G2−0.95G2−0.80
    P IIIx̄ (σ)2.53 (1.40)x̄ (σ)2.60 (1.37)x̄ (σ)2.50 (1.42)x̄ (σ)2.65 (1.36)
    G1−0.56G1−0.61G1−0.50G1−0.63
    G2−0.98G2−0.90G2−1.09G2−0.88
    P IVx̄ (σ)2.79 (1.34)x̄ (σ)2.81 (1.33)
    G1−0.85G1−0.85
    G2−0.51G2−0.50

Supplementary Materials

  • Supplementary Materials

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • Data file S1. R code for all analyses reported here.
    • Movie S1 (.mov format). Annual realization of the MFN from A.D. 500 to 1400 for the study area shown within dotted lines in Fig. 1.

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article