{
  "slug": "the-seeds-beneath-the-steps",
  "title": "The Seeds Beneath the Steps",
  "href": "/strata/the-seeds-beneath-the-steps/",
  "field": "archaeology",
  "claim": {
    "statement": "In situ fossil footprints show that humans were present in North America during the Last Glacial Maximum.",
    "claimants": "Matthew R. Bennett, David Bustos, Jeffrey S. Pigati, Kathleen B. Springer, Thomas M. Urban, Vance T. Holliday, Sally C. Reynolds, Marcin Budka, Jeffrey S. Honke, Adam M. Hudson, Brendan Fenerty, Clare Connelly, Patrick J. Martinez, Vincent L. Santucci, Daniel Odess",
    "citation": "Matthew R. Bennett, David Bustos, Jeffrey S. Pigati, Kathleen B. Springer, Thomas M. Urban, Vance T. Holliday, Sally C. Reynolds, Marcin Budka, Jeffrey S. Honke, Adam M. Hudson, Brendan Fenerty, Clare Connelly, Patrick J. Martinez, Vincent L. Santucci and Daniel Odess. 2021. Evidence of humans in North America during the Last Glacial Maximum. Science 373(6562), 1528-1531. DOI 10.1126/science.abg7586.",
    "year": 2021,
    "headline_as_printed": "calibrated ages that range from 22.86 ± 0.32 to 21.13 ± 0.25 ka (N=11)"
  },
  "records": [
    {
      "role": "claimant-data",
      "name": "seeds.json",
      "path": "data/seeds.json",
      "url": "https://r.jina.ai/http://www.sciencebase.gov/catalog/file/get/6036950cd34eb12031174c77?f=__disk__9f%2F18%2Fef%2F9f18ef4508c50527cb7eeca478eb0cfa5e92b352",
      "original_url": "https://www.sciencebase.gov/catalog/file/get/6036950cd34eb12031174c77?f=__disk__9f%2F18%2Fef%2F9f18ef4508c50527cb7eeca478eb0cfa5e92b352",
      "licence": "Derived factual numeric extract of a USGS data release; the release is \"for the most part\" public domain and may contain copyrighted items",
      "licence_url": "https://www1.usgs.gov/pir/api/identifiers/USGS:6036950cd34eb12031174c77",
      "retrieved": "2026-09-22",
      "sha256": "f12a4a76a75cf85957102de9be207e33ec92141a639600fda596c4117b210954",
      "units": 11
    },
    {
      "role": "control-data",
      "name": "pollen.json",
      "path": "data/pollen.json",
      "url": "https://r.jina.ai/http://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__2a%2F27%2F36%2F2a273645ccb4127836ed9498407f10107cc46aab",
      "original_url": "https://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__2a%2F27%2F36%2F2a273645ccb4127836ed9498407f10107cc46aab",
      "licence": "Derived factual numeric extract of a USGS data release; the release is \"for the most part\" public domain and may contain copyrighted items",
      "licence_url": "https://www1.usgs.gov/pir/api/identifiers/USGS:647782fed34e3ac335becbb0",
      "retrieved": "2026-09-22",
      "sha256": "30d430a6e4c93f17bb9df4bc3920314e2ef778e9743551d9b6076a0c3c6a4405",
      "units": 3
    },
    {
      "role": "control-data",
      "name": "osl.json",
      "path": "data/osl.json",
      "url": "https://r.jina.ai/http://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__9a%2Fe5%2Ffc%2F9ae5fc1ae4020c292e5da2f113131ae475216e3d",
      "original_url": "https://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__9a%2Fe5%2Ffc%2F9ae5fc1ae4020c292e5da2f113131ae475216e3d",
      "licence": "Derived factual numeric extract of a USGS data release; the release is \"for the most part\" public domain and may contain copyrighted items",
      "licence_url": "https://www1.usgs.gov/pir/api/identifiers/USGS:647782fed34e3ac335becbb0",
      "retrieved": "2026-09-22",
      "sha256": "e5e49ba7ffc06f59affe87818ced471f727076e575a4f8963667cfe3eea6c9c3",
      "units": 3
    },
    {
      "role": "reference",
      "name": "context.json",
      "path": "data/context.json",
      "url": "https://r.jina.ai/http://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__2a%2F27%2F36%2F2a273645ccb4127836ed9498407f10107cc46aab",
      "original_url": "https://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__2a%2F27%2F36%2F2a273645ccb4127836ed9498407f10107cc46aab",
      "licence": "Derived factual numeric extract of a USGS data release; the release is \"for the most part\" public domain and may contain copyrighted items",
      "licence_url": "https://www1.usgs.gov/pir/api/identifiers/USGS:647782fed34e3ac335becbb0",
      "retrieved": "2026-09-22",
      "sha256": "7c3677fbb9d89ca3336f7ebbd51fe043a22c467f9e123fc605d95cfc049b7a83",
      "units": 10
    },
    {
      "role": "reference",
      "name": "field-map.json",
      "path": "data/field-map.json",
      "url": "https://r.jina.ai/http://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__f0%2F2c%2F24%2Ff02c24995f233b4e1128254038dbd5d7dda0e4c5",
      "original_url": "https://www.sciencebase.gov/catalog/file/get/647782fed34e3ac335becbb0?f=__disk__f0%2F2c%2F24%2Ff02c24995f233b4e1128254038dbd5d7dda0e4c5",
      "licence": "Derived factual numeric extract of a USGS data release; the release is \"for the most part\" public domain and may contain copyrighted items",
      "licence_url": "https://www1.usgs.gov/pir/api/identifiers/USGS:647782fed34e3ac335becbb0",
      "retrieved": "2026-09-22",
      "sha256": "0bee52bc0bc208cae625729b5750ed0fd6363417542f63d9dfdb6c320b186b47",
      "units": 3
    },
    {
      "role": "reference",
      "name": "layers.json",
      "path": "data/layers.json",
      "url": "https://geography.berkeley.edu/sites/default/files/science.adh5007.pdf",
      "original_url": "https://doi.org/10.1126/science.adh5007",
      "licence": "Factual sample labels transcribed from the text layer of Figure 2A; no figure or article text is reproduced",
      "licence_url": "https://www.science.org/about/science-licenses-journal-article-reuse",
      "retrieved": "2026-09-22",
      "sha256": "1638997c5a3ca93ac8ab520792edfccb7d1f373ee98d1de6d33c719f80b541a8",
      "units": 14
    },
    {
      "role": "reference",
      "name": "intcal20.14c",
      "path": "data/intcal20.14c",
      "url": "https://intcal.org/curves/intcal20.14c",
      "original_url": "https://intcal.org/curves/intcal20.14c",
      "licence": "IntCal20 curve as published by its authors; the article is CC BY 4.0 and no contrary notice is in the curve file",
      "licence_url": "https://creativecommons.org/licenses/by/4.0/",
      "retrieved": "2026-09-22",
      "sha256": "974a66649f2ac8a53e6c99e256b019ac6982f999b12dcf7193162d4c1c09168e",
      "units": 9501
    }
  ],
  "anchor": {
    "what": "All eleven released raw seed ages recalibrated against IntCal20 by the page’s engine; 95.4% envelope midpoints and half-spans compared with the release, headline rows USGS-1810 and USGS-1803.",
    "expected": "22.86 ± 0.32 to 21.13 ± 0.25 ka (N=11); the release also prints 22.87 ± 0.30 ka for USGS-1808",
    "computed": "22.8590 ± 0.3120 ka to 21.1285 ± 0.2485 ka; oldest recomputed midpoint 22.8670 ka (USGS-1808); largest difference from the release 10 calendar years over all 11 rows",
    "agrees": true,
    "tolerance": "20 calendar years per envelope end, midpoint and half-span: printed rounding to 0.01 ka, the curve’s native 10-year spacing here and a whole-year interval routine. Not added dating uncertainty; fixed before the comparison."
  },
  "control": {
    "name": "Three ancient terrestrial-pollen dates from the seed levels, each calibrated separately from its measured F14C, with the published OSL minimum ages carried alongside",
    "citation": "Jeffrey S. Pigati, Kathleen B. Springer, Jeffrey S. Honke, David Wahl, Marie R. Champagne, Susan R. H. Zimmerman, Harrison J. Gray, Vincent L. Santucci, Daniel Odess, David Bustos and Matthew R. Bennett. 2023. Independent age estimates resolve the controversy of ancient human footprints at White Sands. Science 382(6666), 73-75. DOI 10.1126/science.adh5007.",
    "computed": "CAMS-190357A 23.4370 ± 2.4830 ka; CAMS-190358A 22.7705 ± 2.3545 ka; CAMS-190359A 22.6385 ± 2.3365 ka",
    "as_printed": "the resulting calibrated ages range from 23.4 ± 2.5 ka to 22.6 ± 2.3 ka; the minimum OSL age of the sampled horizon is >21.5 ± 1.9 ka"
  },
  "power": {
    "grade": "B-published-sensitivity",
    "planted": "No injection is possible: the laboratory control cannot be rerun. The claim’s printed span, 1.73 ka, is set against the control authors’ printed pollen ranges, and the full printed seed envelope is moved 7,500 calendar years younger, the scale of the modern-analogue argument.",
    "recovered": "Pollen widths 4.97, 4.72, 4.69 ka, all wider than the span and all containing the headline interval; moved envelope 13.38 to 15.68 ka lies 4.62 ka below the youngest pollen edge; resolution threshold 2.88 ka.",
    "verdict": "the control could NOT have confirmed the narrow claim (and the page says inconclusive): its published resolution separates a Last Glacial Maximum age from a chronology about 7,500 calendar years younger only if the pollen dates its layer and the processing correction holds, while the 1.73 ka span, the occupation duration, reworking and the sample-to-track link are INCONCLUSIVE."
  },
  "null_through_claimant_method": {
    "applicable": false,
    "what": "Not applicable. These are chronometric measurements on different materials, not a search statistic whose false discoveries could be reproduced by running the claimants’ procedure on noise. The modern pollen and the procedural blank are real laboratory checks, but they do not give this page a complete, rerunnable contamination model.",
    "result": "No null discovery rate is claimed."
  },
  "verdict": {
    "category": "OPEN",
    "as_of": "2026-09-22",
    "sources": [
      "David Rhode, Christina M. Neudorf, David Rachal, Loren G. Davis, David B. Madsen and Robert Dello-Russo. 2024. Unresolved: Persistent Problems with the White Sands Locality 2 Geochronology. PaleoAmerica 10(1), 10-27. DOI 10.1080/20555563.2024.2345979.",
      "Jeffrey S. Pigati, Kathleen B. Springer, Harrison J. Gray, Matthew R. Bennett and David Bustos. 2024. The Geochronology of White Sands Locality 2 is Resolved. PaleoAmerica 10(1), 28-44. DOI 10.1080/20555563.2024.2376298.",
      "Vance T. Holliday, Jason D. Windingstad, Jordon Bright, Bruce G. Phillips, Joel B. Butler, Ryan Breslawski and James E. Bowman. 2025. Paleolake geochronology supports Last Glacial Maximum (LGM) age for human tracks at White Sands, New Mexico. Science Advances 11(25), eadv4951. DOI 10.1126/sciadv.adv4951.",
      "Dave Rachal and Robert Dello-Russo. 2025. Seeds of controversy: Ecology, depositional context, and radiocarbon dating of Ruppia cirrhosa at the White Sands trackway. Journal of Archaeological Science 179, 106232. DOI 10.1016/j.jas.2025.106232.",
      "Kathleen B. Springer, Jeffrey S. Pigati, David Bustos, Thomas M. Urban and Matthew R. Bennett. 2026. Fossil footprints and Ice Age ecosystems of White Sands National Park. U.S. Geological Survey Fact Sheet 2025-3046. DOI 10.3133/fs20253046."
    ],
    "source_urls": [
      "https://doi.org/10.1080/20555563.2024.2345979",
      "https://www.usgs.gov/publications/geochronology-white-sands-locality-2-resolved",
      "https://pmc.ncbi.nlm.nih.gov/articles/PMC12175891/",
      "https://doi.org/10.1016/j.jas.2025.106232",
      "https://pubs.usgs.gov/publication/fs20253046/full"
    ],
    "would_change": "Independently reproduced dates on securely associated terrestrial material from the footprint surfaces, with a depositional account that directly tests reworking and the tie between each dated layer and each surface; a direct, independently reproduced measurement of a large bias in the seed or pollen dates, going beyond the carbon-isotope arguments for one that are already published and that the claimants’ reply rejects; or a peer-reviewed reconciliation of the two positions."
  },
  "decided_by": "not-yet",
  "years_to_decision": null,
  "years_to_decision_note": "No decision date is asserted; the record is still argued as of 2026-09-22.",
  "choices": [
    {
      "id": "evidence",
      "label": "Evidence shown in the trench",
      "options": [
        "seeds",
        "pollen",
        "all"
      ],
      "default": "seeds",
      "affects": [
        "visible determination count",
        "trench figure rows",
        "OSL panel"
      ],
      "inert": false
    },
    {
      "id": "scenario",
      "label": "Trench scenario",
      "options": [
        "measured",
        "younger"
      ],
      "default": "measured",
      "affects": [
        "seed envelope in the trench",
        "Last Glacial Maximum containment",
        "gap to the pollen"
      ],
      "inert": false
    },
    {
      "id": "statistic",
      "label": "Which statistic the release printed",
      "options": [
        "midpoint",
        "mean"
      ],
      "default": "midpoint",
      "affects": [
        "rows within tolerance",
        "largest difference"
      ],
      "inert": false
    },
    {
      "id": "pair",
      "label": "Same-horizon seed and pollen pair",
      "options": [
        "USGS-1803",
        "USGS-1828",
        "USGS-1806",
        "USGS-1805",
        "USGS-1829",
        "USGS-1807"
      ],
      "default": "USGS-1803",
      "affects": [
        "seed distribution",
        "matched pollen",
        "envelope gap",
        "selected sweep row"
      ],
      "inert": false
    },
    {
      "id": "reservoir",
      "label": "Assumed seed reservoir excess R, radiocarbon years",
      "options": [
        0,
        100,
        200,
        300,
        400,
        500,
        600,
        700,
        800,
        900,
        1000,
        1100,
        1200,
        1300,
        1400,
        1500,
        1600,
        1700,
        1800,
        1900,
        2000,
        2100,
        2200,
        2300,
        2400,
        2500,
        2600,
        2700,
        2800,
        2900,
        3000,
        3100,
        3200,
        3300,
        3400,
        3500,
        3600,
        3700,
        3800,
        3900,
        4000,
        4100,
        4200,
        4300,
        4400,
        4500,
        4600,
        4700,
        4800,
        4900,
        5000,
        5100,
        5200,
        5300,
        5400,
        5500,
        5600,
        5700,
        5800,
        5900,
        6000,
        6100,
        6200,
        6300,
        6400,
        6500,
        6600,
        6700,
        6800,
        6900,
        7000,
        7100,
        7200,
        7300,
        7400,
        7500,
        7600,
        7700,
        7800,
        7900,
        8000
      ],
      "default": 0,
      "affects": [
        "seed calibration",
        "envelope gap",
        "calendar shift of the midpoint"
      ],
      "inert": false
    },
    {
      "id": "convention",
      "label": "Scenario convention for the pair",
      "options": [
        "radiocarbon",
        "calendar"
      ],
      "default": "radiocarbon",
      "affects": [
        "seed distribution",
        "envelope gap"
      ],
      "inert": false
    },
    {
      "id": "domain",
      "label": "Pollen measurement-domain diagnostic",
      "options": [
        "fraction",
        "age"
      ],
      "default": "fraction",
      "affects": [
        "diagnostic midpoint",
        "diagnostic intervals",
        "source discrepancy"
      ],
      "inert": false
    }
  ],
  "headline": "The pollen supports a Last Glacial Maximum date for the footprint layers, but its published error bars are too broad to confirm the 1.73 ka span between the seed dates, and no calibration can test how the dated material came to lie beside the footprints.",
  "novelty": "we searched the open web, GitHub-indexed results and the repository's existing strata on 2026-09-22 and did not find an interactive six-pair sweep of White Sands seed reservoir scenarios against separately recalibrated pollen measurements.",
  "ledger": {
    "claim_reproduced": {
      "value": true,
      "assertion": "anchor:all-eleven-raw-seed-calibrations"
    },
    "control_computed": {
      "value": true,
      "assertion": "control:three-fraction-calibrations-and-sweep"
    },
    "control_can_confirm": {
      "value": false,
      "assertion": "power:grade-B-published-sensitivity-no-injection"
    },
    "rendered_figures_asserted": {
      "value": true,
      "assertion": "surface:bound-figures-quotes-head-browser"
    },
    "choices_are_live": {
      "value": true,
      "assertion": "choices:each-moves-its-output"
    },
    "planted_fault_caught": {
      "value": true,
      "assertion": "fault:raw-pollen-seed-and-curve-corruption"
    },
    "refusal_asserted": {
      "value": true,
      "assertion": "refuse:non-dates-bad-inputs-and-inferences"
    },
    "provenance_pinned": {
      "value": true,
      "assertion": "provenance:sha256-and-quote-audit"
    },
    "verdict_dated": {
      "value": true,
      "assertion": "verdict:open-dated-sourced-would-change"
    }
  }
}