Sunflower as a Pre-Columbian Domesticate in

Mexico

Images from Google Images

• The extant cultivated sunflower, Helianthus annuus is thought to be independently domesticated in eastern North America

• Recent archaeological evidences in Mexico urged several researchers to look for sunflower domestication in Mesoamerican regions

• The facts have been much debated

Evidences of Mesoamerican Domestication

• Three lines of evidences proposed by Lentz et al. (2008)

- Archaelogical data- Linguistic and ethnographic data- Ethnohistorical data

Archaelogical Evidences• Several wild sunflower species

are native to Mexico• Pre-Columbian archaeological

remains of wild sunflower • In coprolites in Ocampo Cave,

Tamaulipas, Mexico: 2900-2200 cal B.C.

• 10 achenes from wild annuus at Tenochtitlan, Mexico

Archaelogical Evidences• Early domesticated sunflower

remainsSan Andres site in Tabasco, Mexico

• An achene (2867-2482 cal B.C.) and a seed (2875-2575 cal B.C.)

Predates all the archeological sunflower remains

Archaelogical EvidencesCueva del Gallo, Morelos, Mexico

• Three large achenes (~ 290 cal B.C.)• Characteristic domestication

syndromes:- Twist in the fruit from crowded

domesticated sunflower head- Biggest of all excavated sunflower

achenes; outside of wild sunflower dimentions

Mexican dissemules represent a distinct lineage from eastern North American sunflower populations

Smith’s Letter

• Archeological evidences for domesticated sunflower in pre-Columbian Mesoamerica are inadequate

- No plant remains other than seeds and achenes

- Taxonomic problems: Santa Leticia achene misclassified

- Insufficient morphological descriptors

- 3 Morelos specimens may represent introduced domesticated sunflower

Despite smaller sample size, San Andres specimens represent earliest fully domesticated sunflower Paleoethnobotany is recent and/or Mexican sites are not favorableSanta Leticia is outside of wild sunflower locale PNAS reviewers “scrutinized” the factsMexican domestication may predate eastern North American domestication

and Lentz’s Reply

Linguistic and Ethnographic Data

• Distinctive names and lack of phonetic resemblance to the Spanish terms suggests pre-Columbian existence

Brown’s Letter• Linguistic evidence is severely

deficient to suggest sunflower as an pre-Columbian domesticate in Mesoamerica

- Semantically transparent names are commonplace

- Mesoamerican names generated from ancestral languages Sunflower doesn’t have one in proto-languages of earlier peroids

- No record of an word for sunflower in primitive languages of Mesoamerica

The linguistic evidence and archaeological data together demonstrate the use of domesticated sunflower in pre-Columbian times

So, what would be the cultigen called if there was no word for sunflower?

and Lentz’s Reply

Ethnohistoric Data• Chimalacatl/chimalxochitl/

chimalsuchitl represents sunflower in modern indigenous Nahua (the Aztecs) group

• Spanish conquerors documented presence of sunflower in indigenous Aztecs

• Sahagun’s Florentine Codex illustrates sunflower as a symbol representing shield

• Rulers carried jeweled sunflowersPortrait: Netzahaulapilli, the Aztec ruler of Tetcoco

Heiser Lentz

Don’t look like sunflowers

Can’t be anything elseLarge receptacleLong peduncleRay and disk floretsBig flowersLabeled as “chimalsuchitl”

Heiser’s Letter

• Historical records suggesting pre-Columbian domestication of sunflower in Mesoamerica is altogether lacking

- Same nomenclature was used to represent more than one plant

The historical records presented are relevant

Not all drawings are from original artists Printers shared illustrations

and Lentz’s Reply

Why Mesoamerican domesticate remained so obscure?• Independent Eastern North American domestication model was

widely acceptedLack of archaeological evidences:• Archaeologically unfavorable environment in the neotropical regions• A lag in paleoethnobotanical researchNot much exploited as North American domesticate:• More a symbolic than direct feed source• Predominance of alternative fat sources in Mesoamerican diets• Not extensively grown• Spanish conquest suppressed symbolic assets of indigenous peopleMesoamerican landraces have not been scrutinized the way their North American counterparts have been

DNA evidences: the “ultimate truth”- Two references to the molecular studies:

1. Harter AV, et al. (2004) Origin of extant domesticated sunflowers in eastern North America. Nature 430:201-205

2. Wills DM, Burke JM (2006) Chloroplast DNA variation confirms a single origin of domesticated sunflower (Helianthus annuus L.). J Hered 97:403-408

Harter AV, et al. (2004) Origin of extant domesticated sunflowers in eastern North America. Nature 430:201-205

• Primers flanking 18 microsatellite markers spanning sunflower genome

• 21 wild H. annuus, 8 Native American and Mexican landraces, and two elite cultivars

• STRUCTURE analysis• “Extant germplasm

arose from wild populations in the central USA”

Wills DM, Burke JM (2006) Chloroplast DNA variation confirms a single origin of domesticated sunflower

(Helianthus annuus L.). J Hered 97:403-408

• Primers flanking 6 polymorphic cpSSR markers

• 26 wild H. annuus, 15 domesticated lines

• Chloroplast haplotypes were analyzed

• “Single origin of the extant domesticated sunflowers outside of Mexico”

Rieseberg and Burke’s Letter• All available molecular data

are suggestive of a single origin outside of Mexico -Mexican landraces that had

conspicuous uniqueness to their phenotypes shared chloroplast haplotypes of the US domesticates- Bigger achenes of Mexican

remains do not preclude North American dissemination

Molecular studies have not ventured Mexican domesticatesMight have hybridized with modern varieties

and Lentz’s Reply

Thank You

Bibliography• Brown CH. 2008. A Lack of Linguistic Evidence for Domesticated Sunflower in Pre-Columbian

Mesoamerica. PNAS 105(30):E47• Harter AV, et al. 2004. Origin of Extant Domesticated Sunflowers in Eastern North America.

Nature 430:201-205.• Heiser CB. 2008. How Old is the Sunflower in Mexico? PNAS 105(30):E48.• Lentz DL, et al. 2001. Prehistoric Sunflower (Helianthus annuus L.) Domestication in Mexico.

Econ Bot 53(3):370-376.• Lentz DL, et al. 2008. Reply to Rieseberg and Burke, Heiser, Brown, and Smith: Molecular,

Linguistic, and Archaelogical Evidence for Domesticated Sunflower in Pre-Columbian Mesoamerica. PNAS 105(30):E49-E40.

• Rieseberg L and JM Burke. 2008. Molecular Evidence and the Origin of the Domesticated Sunflower. PNAS 105(30):E46.

• Smith BD. 2008. Winnowing the Archaeological Evidence for Domesticated Sunflower in Pre-Columbian Mesoamerica. PNAS 105(30):E45

• Wills, DM and JM Burke. 2006. Chloroplast DNA Variation Confirms a Single Origin of Domesticated Sunflower (Helianthus annuus L.). J Hered 97(4):403-408.