WHAT IS IT?
Maize pollen grain
About 5,000 years old
At the Kob site, northern Belize
About 50 microns in diameter, equivalent to a speck of dust. Lined up next to each other, 2,500 of them would equal one inch.
This microscopic maize pollen grain from Belize helped transform our understanding of early Mesoamerican farmers. During the last century, archaeologists searched for evidence of the origins and the spread of agriculture in the New World among the remains of corncobs and seeds in the highland regions of Mexico (where organic remains are often well preserved).
(Courtesy John Jones)
In the tropical lowlands, wet soil led to few discoveries of plant remains of any sort. Most archaeologists gave up looking, believing that tropical soils held virtually no evidence of early cultivation. But a decade ago, John Jones of Washington State University, working at the lowland site of San Andrés in the Mexican state of Tabasco, found fossil maize pollen in soils more than 7,000 years old. His report was questioned because the pollen grains were small, and some argued that they might belong to another grass. Then botanists and archaeologists started to find more intact pollen—like this grain from the 5,000-year-old Kob site in Belize—in addition to starch grains and ancient phytoliths (plant crystals). The results have been breathtaking. When taken as a whole, the microscopic evidence from early cultivated plants confirms that farming began in the lowlands of South America and then spread
to Central America, Mexico, and the Caribbean islands. Archaeologists now believe that plants were cultivated in the New World as early as 10,000 years ago, making them as old as the first crops in the Near East.
© 2007 by the Archaeological Institute of America