Puerto Rican origins and Maize

Nice letter in yesterday's edition of Nature in which the authors point out that maize DNA in human coprolites from Vieques Island off Puerto Rico does not imply an origin in the Bolivian Andes, for the obvious reason that maize was widespread, not to mention that it had already arrived in the area at an earlier date.

Pagán-Jiménez, Jaime R., Reniel Rodriguez-Ramos, and José R. Oliver (2014). Ancient Cultures: Maize is not a clue to Puerto Rican Origins. Nature 510:473.