decoration and vessel shape, pointing to techniques of incising. The Early to Middle Jomon pottery had antecedents dating 10,000 years, but the Valdivia pottery style seemed to have developed rather quickly. In 1962 three archeologists, Ecuadorian Emilio Estrada and Americans Clifford Evans and Betty Meggers suggested that Japanese fishermen had gotten blown to Ecuador in a storm and introduced their ceramics to Valdivia at that time. Their theory was based on the idea of diffusion of style and techniques. Their concept was challenged at the time by other archaeologists, who argued that there were strong logistical challenges to the idea that Japanese could have survived what would have been nearly a year and a half voyage in dugout canoes. The cultures were separated by a distance of 15,000 km (8,000 nautical miles). Researchers argued that Valdivia ceramics (and culture) had developed independently, and those apparent similarities were a result simply of constraints on technique, and an "accidental convergence" of symbols and style. In the 1970s, what is believed widely to be conclusive evidence refuting the diffusion theory was found at the Valdivia type-site, as older pottery and artifacts were found below these excavations. Researchers found what is called San Pedro pottery, pre-dating Phase A and the Valdivia style. It was more primitive. Some researchers believe pottery may have been introduced by people from northern Colombia, where comparably early pottery was found at the Puerto Hormiga archaeological site. In addition, they think that the maize at Valdivia was likely introduced by people living closer to Meosamerica, where it was domesticated. In addition, other pottery remains of the San Pedro style were found at sites about 5.6 miles (9 km) up the river valley. Additional research at both several coastal sites, including San Pablo, Real Alto, and Salango, and Loma Alta, Colimes, and San Lorenzo del Mate inland have resulted in a major rethinking of Valdivian culture. It has been reclassified as representing a "tropical forest culture" with a riverine settlement focus. There has been major re-evaluation of nearly every aspect of its culture. References External links Ecuadorian Archaeology Valdivia stone carving Pre-Columbian cultures History of Ecuador Indigenous peoples in Ecuador Indigenous peoples of the Andes Archaeology of Ecuador 4th millennium BC Archaic period in the Americas