Gourd Invasion Beat Europeans Across Atlantic

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Bottle gourds’ wild ancestors may have crossed the Atlantic Ocean on the currents that run from western Africa to the Caribbean and South America thousands of years before Europeans made similar voyages.

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A recent genetic analysis found that ancient gourds (Lagenaria siceraria) from the western hemisphere carried the DNA signature of African wild gourds. Those hard-skinned fruits could have floated across the Atlantic in as little as 100 days, with an average sea voyage of approximately nine months. The Proceedings of the National Academy of Sciences (PNAS) published a study that presented both the genetic analysis and travel time estimates.

The wild gourds simply floated from their homeland in Africa to the Western Hemisphere. Once the floating fruit reached new lands, the seeds within sprouted and animals distributed the plants even further. Wild gourd seeds have been found in mastodon dung in Florida, noted the study’s authors, led by post-doctoral researcher Logan Kistler of Penn State.

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After the wild gourds established themselves of dry land, humans may have domesticated the plant in multiple places independently, suggested the study authors. The fruits’ sea-going ability allowed bottle gourds to be the only domesticated crop with a global distribution before the 1500′s. Domesticated gourds first appeared in archeological finds in the western Hemisphere from 10,000 years ago. People used the dried shell of the gourds to make water bottles, spoons, bowls and other items. In some places, such as the coast of western South America, people likely used gourds as containers before inventing ceramic pots.

Earlier studies suggested that bottle gourds may have accompanied prehistoric people as they crossed the now-submerged land bridge from Asia to North America in the Arctic. The PNAS study authors pointed out that the early Native Americans would have needed to cultivate the gourds in the frigid north as they migrated. However, gourds need warm weather to grow.

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Gourds also need animals to move their seeds around. In Africa, wild gourds are nearly extinct. The wild gourds that floated to distant lands completely disappeared, possibly because they depended on large animals, like mastodons and giant sloths, to disburse their seeds to new inland areas. Luckily for the gourds, humans took the place of mastodons and continue to cultivate the domesticated descendants of the pioneer gourds. For example, I have six huge dried gourds from a single plant that dominated my garden, climbed the grape arbor and scaled a cedar tree. Someday, those gourds will be turned into bird houses.