During the Ice Age, the Iberian Peninsula was a closed system, surrounded in the South, East and West by the sea, and separated by the glaciers of the Pyrenees from the tundra in the North. The Riss interglacial period ending with the Würm glaciation (Weichsel, Wisconsin glaciation) was the last glacial period which lasted from 115,000 to 10,000 years ago, during which time the coldest period was from 60,000 to 18,000 years ago. It is improbable that Vitis silvestris migrated during the Quaternary Age (the Late Pleistocene); it is more probable that it emigrated in the Holocene epoch along the coastal stretches of the Bay of Biscay and to the North over the broad land formation which existed at the time at Roussillon. One can therefore assume that the Iberian Vitis silvestris gene pool developed in isola‑ tion from and independently to the other gene pools (cf. Negrul, 1958, 1959; Turkovíc, 1961). It was only later, with the advent of sea travel, that one can assume that V. sativa and V. vinifera were imported by migrating human populations, and must have been mixed as a mass crop by pollination with the regional Vitis silvestris.