Squash (Cucurbita Pepo) is one of the major and earliest plant domesticated in Mesoamerica, along with maize and bean. Earliest archaeological evidence comes from excavation carried out during the 1950s and 1960s in five caves in Mexico: Guilá Naquitz (Oaxaca), Coxcatlán and San Marco caves (Puebla) and Romero’s and Valenzuela’s caves (Tamaulipas).
During the original excavation in Guilá Naquitz cave, directed by Kent Flannery, in 1966, Pepo squash seeds, fruit rind fragments and stems were dated through indirect radiocarbon analysis to 10,000 years B.P. These specimens, whose size and thickness identified them as domesticated, were thought by other archaeologists to come from later occupation levels and, therefore, not to represent a reliable evidence.
A recent reexamination and AMS-direct dating of the seeds from Guilá Naquitz and Coxcatlán cave by archaeologist Bruce Smith from the Smithsonian Institute supported the 10,000 years old date. This analysis allowed also to trace the dispersion of the plant between 10,000 and 8,000 years ago from south to north, specifically, from Oaxaca and southwestern Mexico toward Northern Nexico and southwestern United States.
Other Examples of Domesticated Pepo Squash in North America
In the United States, early evidence of initial domestication of Pepo squash comes from different sites in Missouri, Florida, Pennsylvania, Kentucky, Tennessee and Maine. This was a subspecies of Cucurbita Pepo called Cucurbita Pepo Ovifera and its wild ancestor, the Ozark gourd, is still present in the area.
Recent studies on this example of squash remains from mid-Holocene (8000-4000 B.P.) contexts have produced two main hypotheses for the use of the fruit. One idea is that since the bitterness of the fruits would have made them inedible, these were processed to eliminate the bitterness from the seeds and then eaten. A further hypothesis, far more interesting and not necessarily exclusive, is that the dried fruits were used as fishnet floats and/or containers for food and liquids.
This last hypothesis fits well with evidence of use of squash and gourds from other pre-Columbian regions, such as Mesoamerica, where squashes were desiccated and used as containers since very early times and where early examples of pottery imitated in shape and decoration squashes and gourds.
Sources
This glossary entry is a part of the About.com guide to Plant Domestication, and the Dictionary of Archaeology.
Hart, John P., Robert A. Daniels, Charles J. Sheviak, 2004, Do Cucurbita pepo Gourds Float Fishnets? American Antiquity, Vol. 69, No. 1, pp. 141-148
Smith, Bruce D., 1997, The Initial Domestication of Cucurbita pepo in the Americas 10,000 Years Ago, Science 276, pp. 932-934
Smith, Bruce D., 2001, Documenting Plant Domestication: The Consilience of Biological and Archaeological Approaches, Proceedings of the National Academy of Sciences of the United States of America, Vol. 98, No. 4, pp. 1324-1326.
Smith, Bruce D., 2005, Reassessing Coxcatlán Cave and the early history of domesticated plants in Mesoamerica, Proceedings of the National Academy of Sciences of the United States of America, Vol. 102, No. 27, pp. 9438-9445.