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January 18, 2012

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Ancient South Americans ate popcorn, study finds

Jan. 19, 2012
Courtesy of the Smithsonian Tropical Research Institute
and World Science staff

Peo­ple along the coast of modern-day Pe­ru were crunch­ing on pop­corn more than 3,000 years ago, ac­cord­ing to a new stu­dy.

The pre­his­tor­ic pop­ping took place 1,000 years ear­li­er than pre­vi­ously re­ported, and be­fore ce­ram­ic pot­tery was used in the ar­ea, said the re­search­ers, re­port­ing their find­ings in the jour­nal Pro­ceed­ings of the Na­t­ional Acad­e­my of Sci­ences.

The sci­en­tists said char­ac­ter­is­tics of an­cient cob­s—the ear­li­est ev­er found in South Amer­i­ca—indi­cate that the lo­cal in­hab­i­tants ate corn sev­eral ways, in­clud­ing pop­corn and flour corn. But corn was­n’t a yet ma­jor part of the di­et, as it would be la­ter, when it be­came a key fea­ture of the New World’s cul­ture.

The re­mains were da­ted to 6,700 to 3,000 years ago.

The cobs were found at Pare­dones and Huaca Pri­eta, two mound sites on Pe­ru’s ar­id north­ern coast. The re­search group, led by Tom Dille­hay from Van­der­bilt Uni­vers­ity in Nash­ville, Tenn. and Duc­cio Bonavia from Pe­ru’s Ac­a­dem­ia Na­cional de la His­to­ria, al­so found mi­cro­scop­ic fos­sils of corn in the form of starch grains and phy­toliths, hard mi­cro­scop­ic bod­ies that form in cer­tain liv­ing plants.

“Corn was first domestica­ted in Mex­i­co nearly 9,000 years ago from a wild grass called teosin­te,” though this plant looks very dif­fer­ent from corn, said Do­lo­res Piperno, a co-author of the study with the Smith­so­nian In­sti­tu­tion’s Na­t­ional Mu­se­um of Nat­u­ral His­to­ry in Wash­ing­ton, D.C. 

“Our re­sults show that only a few thou­sand years la­ter corn ar­rived in South Amer­i­ca where its ev­o­lu­tion in­to dif­fer­ent va­ri­eties that are now com­mon in the An­de­an re­gion be­gan. This ev­i­dence fur­ther indica­tes that in many ar­e­as corn ar­rived be­fore pots did and that early ex­pe­ri­menta­t­ion with corn as a food was not de­pend­ent on the pres­ence of pot­tery.”

Sci­en­tists have had dif­fi­cul­ty un­der­stand­ing the sub­tle trans­forma­t­ions in the char­ac­ter­is­tics of cobs and ker­nels that led to the hun­dreds of maize, or corn, rac­es known to­day. Corn­cobs and ker­nels weren’t well pre­served in the hu­mid trop­i­cal forests be­tween Cen­tral and South Amer­i­ca, in­clud­ing Pana­ma—the pri­ma­ry dis­per­sal routes for the crop af­ter it first left Mex­i­co about 8,000 years ago.

“These new and un­ique rac­es of corn may have de­vel­oped quickly in South Amer­i­ca, where there was no chance that they would con­tin­ue to be pollina­ted by wild teosin­te,” said Piperno. “Be­cause there is so lit­tle da­ta avail­a­ble from oth­er places for this time pe­ri­od, the wealth of mor­pho­log­i­cal [struc­tur­al] in­forma­t­ion about the cobs and oth­er corn re­mains at this early da­te is very im­por­tant for un­der­stand­ing how corn be­came the crop we know to­day.”

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People along the coast of modern-day Peru were crunching on popcorn more than 3,000 years ago, according to a new study. The prehistoric popping took place 1,000 years earlier than previously reported, and before ceramic pottery was used in the area, said the researchers, reporting their findings in the journal Proceedings of the National Academy of Sciences. The scientists said characteristics of ancient cobs—the earliest ever found in South America—indicate that the local inhabitants ate corn several ways, including popcorn and flour corn. But corn wasn’t a yet major part of the diet, as it would be later, when it became a key feature of the New World’s culture. The remains were dated to 6,700 to 3,000 years ago. The cobs were found at Paredones and Huaca Prieta, two mound sites on Peru’s arid northern coast. The research group, led by Tom Dillehay from Vanderbilt University in Nashville, Tenn. and Duccio Bonavia from Peru’s Academia Nacional de la Historia, also found microscopic fossils of corn in the form of starch grains and phytoliths, hard microscopic bodies that form in certain living plants. “Corn was first domesticated in Mexico nearly 9,000 years ago from a wild grass called teosinte,” though this plant looks very different from corn, said Dolores Piperno, a co-author of the study with the Smithsonian Institution’s National Museum of Natural History in Washington, D.C. “Our results show that only a few thousand years later corn arrived in South America where its evolution into different varieties that are now common in the Andean region began. This evidence further indicates that in many areas corn arrived before pots did and that early experimentation with corn as a food was not dependent on the presence of pottery.” Scientists have had difficulty understanding the subtle transformations in the characteristics of cobs and kernels that led to the hundreds of maize, or corn, races known today. Corncobs and kernels weren’t well preserved in the humid tropical forests between Central and South America, including Panama—the primary dispersal routes for the crop after it first left Mexico about 8,000 years ago. “These new and unique races of corn may have developed quickly in South America, where there was no chance that they would continue to be pollinated by wild teosinte,” said Piperno. “Because there is so little data available from other places for this time period, the wealth of morphological [structural] information about the cobs and other corn remains at this early date is very important for understanding how corn became the crop we know today.”