The research reveals that the sweet potato evolved just once, probably in central or northern South America, and originated from a single ancestor. What’s more, an analysis of part of a 250-year-old sweet potato plant collected during Captain Cook’s voyage to the South Pacific on HMS Endeavour suggests the spuds arrived in Polynesia by means of ocean currents. “All the evidence points to Ipomoea trifida being the only species with a role in the origin of the sweet potato,” said Muñoz-Rodríguez. Further evidence for the idea came from a sweet potato plant collected by the naturalist Joseph Banks during Captain Cook’s voyage to Polynesia in 1769. “[It is] the oldest sweet potato specimen known from Polynesia,” said Muñoz-Rodríguez.

Source: The Guardian April 12, 2018 16:01 UTC