{
  "id": "common-bean-out-of-the-americas",
  "type": "entity",
  "name": "The common bean out of the Americas — two crops, one Iberian doorway",
  "summary": "Phaseolus vulgaris was domesticated twice, in Mesoamerica and in the Andes, from wild pools that had parted about 165,000 years earlier. Both reached Europe through Iberia in the sixteenth century, and there they did something they had not done at home: they interbred. European landraces carry three to four times the inter-pool hybrids of American ones - on one count. A second study of 782 accessions puts the figure far lower, and both numbers are here.",
  "locale": "en",
  "tags": [
    "columbian-exchange",
    "agriculture",
    "americas",
    "botany",
    "spain",
    "genetics",
    "sixteenth-century",
    "science"
  ],
  "relations": [
    {
      "rel": "related",
      "target": "columbian-exchange"
    },
    {
      "rel": "related",
      "target": "capsicum-out-of-the-americas"
    },
    {
      "rel": "related",
      "target": "tomato-in-sixteenth-century-europe"
    },
    {
      "rel": "related",
      "target": "sweet-potato-and-the-manila-galleon"
    },
    {
      "rel": "related",
      "target": "nixtamalization-and-the-maize-transfer"
    }
  ],
  "questions": [
    "Where does the common bean come from?",
    "Was the common bean domesticated once or twice?",
    "How did the common bean reach Europe?",
    "Why are European beans genetically different from American ones?",
    "Which American bean gene pool dominates in Europe?"
  ],
  "claims": [
    {
      "id": "c1",
      "text": "There is no single origin to transfer. The reference genome analysis finds two independent domestications of Phaseolus vulgaris, about 8,000 years ago, from wild gene pools that had already diverged about 165,000 years ago, with a confidence interval of 146,000 to 184,000 years. The wild Andean population was itself derived from the Mesoamerican one by a founding event of only several thousand individuals, after which it showed no appreciable growth in effective population size for about 76,000 years.",
      "sources": [
        "schmutz-2014-common-bean-dual-domestication"
      ],
      "confidence": 0.85
    },
    {
      "id": "c2",
      "text": "The two domestications took different genetic routes to the same crop. The Mesoamerican domestication shows 930 selection windows totalling 74 megabases, the Andean 750 windows totalling 60 megabases, and only 7.234 megabases of the regions implicated in domestication are shared between them. Farmers on two continents solved the same problem twice with largely different genes.",
      "sources": [
        "schmutz-2014-common-bean-dual-domestication"
      ],
      "confidence": 0.85
    },
    {
      "id": "c3",
      "text": "What Spanish and Portuguese ships carried across, therefore, was not one plant but two. The genetics literature repeats a specific chronology for it - Mesoamerican landraces arriving in Europe through Spain and Portugal in 1506, Andean ones in similar fashion after Pizarro's exploration of Peru in 1528. Both papers state this as received history in their introductions and neither cites a document for it, so it is carried here at low confidence and flagged: it is what plant geneticists believe historians have established, not something their own data can date.",
      "sources": [
        "gioia-2013-european-common-bean",
        "pipan-meglic-2019-european-bean-progression"
      ],
      "confidence": 0.5
    },
    {
      "id": "c4",
      "text": "Europe then did something the Americas had not. Typing 256 European and 89 American landraces with 13 nuclear and 6 chloroplast microsatellites plus phaseolin and the Pv-shatterproof1 marker, one study found inter-gene-pool hybrids in 40.2 per cent of the European accessions against 12.3 per cent of the American - nearly four times as many. Two lineages that had been apart for a hundred and sixty thousand years were put in adjacent rows and allowed to cross.",
      "sources": [
        "gioia-2013-european-common-bean"
      ],
      "confidence": 0.85
    },
    {
      "id": "c5",
      "text": "The crossing had to matter, because the crossing was all that stood between Europe and a much poorer bean. Measured on pure accessions only, the introduction bottleneck was real and lopsided: the Mesoamerican material lost about five times more diversity than the Andean, a fall in expected heterozygosity of 0.29 against 0.06. In the same study the Andean type ended up dominant in Europe, at 76 per cent against 24 per cent Mesoamerican.",
      "sources": [
        "gioia-2013-european-common-bean"
      ],
      "confidence": 0.8
    },
    {
      "id": "c6",
      "text": "A larger survey does not agree, and the disagreement is not a rounding error. Typing 782 accessions from nine gene banks and twelve European countries with 33 microsatellite markers, it reports 62 per cent Andean, 25.8 per cent Mesoamerican and 12.2 per cent of mixed origin. Against the earlier 40.2 per cent that is a threefold gap in the one figure the story turns on. Different marker sets, different sampling and different thresholds for calling an accession a hybrid can produce it; the honest statement is that inter-pool hybrids are common in Europe and rarer in the Americas, and that their European share is somewhere between about a tenth and about two fifths.",
      "sources": [
        "pipan-meglic-2019-european-bean-progression",
        "gioia-2013-european-common-bean"
      ],
      "confidence": 0.7
    },
    {
      "id": "c7",
      "text": "The same larger survey finds direction in the European material. Diversity runs from the western parts of southern Europe - Portugal, Spain, Italy, Slovenia - eastwards, with three geographically separated subgroups forming to the north, south and centre of the eastern range. The variance partition says why the map is faint rather than sharp: 89 per cent of molecular variability sits within individual accessions and only 4 per cent among the twelve countries of origin.",
      "sources": [
        "pipan-meglic-2019-european-bean-progression"
      ],
      "confidence": 0.8
    },
    {
      "id": "c8",
      "text": "The credit divides accordingly, and the division is the point. The crop was made twice over by Mesoamerican and Andean farmers across eight millennia, and nothing in the European record adds a domestication trait. What the Iberian passage contributed was an arena: two pools that had been separated by geography since long before anyone farmed them were carried to the same gardens within a generation of each other and left to recombine. That is a real and measurable contribution and it is also a small one beside the original domestications, and both statements belong in the same sentence.",
      "sources": [
        "schmutz-2014-common-bean-dual-domestication",
        "gioia-2013-european-common-bean"
      ],
      "confidence": 0.8
    },
    {
      "id": "c9",
      "text": "None of the three studies cited here is a historical one. They date divergence and domestication from genomes and they date the crossing to Europe from a footnote in their own introductions. No herbal, port record, customs book or monastic account is read in this object, and the sixteenth- century half of the story therefore rests on authority this corpus has not checked. A later object that opens a printed herbal or a shipping record should override the dates given above.",
      "sources": [
        "gioia-2013-european-common-bean",
        "pipan-meglic-2019-european-bean-progression",
        "schmutz-2014-common-bean-dual-domestication"
      ],
      "confidence": 0.85
    }
  ],
  "takeaways": [],
  "faqs": [],
  "evidence_tier": "secondary",
  "evidence": {
    "level": "industry_observation",
    "source_types": [
      "paper"
    ]
  },
  "moat_flag": false,
  "winning_edge": "Ask where beans come from and the web answers \"the Americas\", which is true and useless. This object gives the shape that matters: two separate domestications from pools that split about 165,000 years ago, with almost disjoint selection landscapes, so the Iberian transfer moved two crops and not one; the measured asymmetry of the bottleneck, which hit the Mesoamerican material about five times harder; and the inter-pool hybridisation that Europe produced and the Americas largely had not. It then does what no popular account does - prints the two published estimates of the European hybrid share, 40.2 per cent and 12.2 per cent, side by side instead of picking the more striking one, and says out loud that the 1506 and 1528 dates everyone repeats come from the introductions of genetics papers, not from a document anyone here has read.",
  "confidence": 0.8,
  "last_verified": "2026-08-13",
  "canonical_url": "https://hispanic-legacy.com/k/common-bean-out-of-the-americas",
  "api_url": "https://hispanic-legacy.com/api/k/common-bean-out-of-the-americas.json",
  "jsonld": {
    "@context": "https://schema.org",
    "name": "The common bean out of the Americas — two crops, one Iberian doorway",
    "description": "Phaseolus vulgaris was domesticated twice, in Mesoamerica and in the Andes, from wild pools that had parted about 165,000 years earlier. Both reached Europe through Iberia in the sixteenth century, and there they did something they had not done at home: they interbred. European landraces carry three to four times the inter-pool hybrids of American ones - on one count. A second study of 782 accessions puts the figure far lower, and both numbers are here.",
    "url": "https://hispanic-legacy.com/k/common-bean-out-of-the-americas",
    "license": "https://spdx.org/licenses/CC-BY-4.0.html",
    "dateModified": "2026-08-13",
    "citation": [
      {
        "@type": "CreativeWork",
        "name": "Evidence for Introduction Bottleneck and Extensive Inter-Gene Pool (Mesoamerica x Andes) Hybridization in the European Common Bean (Phaseolus vulgaris L.) Germplasm",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC3788063/"
      },
      {
        "@type": "CreativeWork",
        "name": "Diversification and genetic structure of the western-to-eastern progression of European Phaseolus vulgaris L. germplasm",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC6813049/"
      },
      {
        "@type": "CreativeWork",
        "name": "A reference genome for common bean and genome-wide analysis of dual domestications",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC7048698/"
      }
    ],
    "@type": "Article",
    "headline": "The common bean out of the Americas — two crops, one Iberian doorway"
  }
}