I grew up in Mexico City where I worked in various capacities--the best job I ever had was as a historical consultant for telenovelas (soap operas). After getting a PhD in history at the University of Chicago, I taught at Yale, the University of Helsinki, and UC Davis. I have written about the history of border regions (Changing National Identities at the Frontier--Cambridge University Press, 2005), early European exploration (A Land So Strange--Basic Books, 2007), and the enslavement of Native Americans (The Other Slavery--Houghton Mifflin Harcourt, 2016). More recently, I have focused on the "Columbian moment" in the Pacific, beginning with the first expedition that went from America to Asia and back (1564-1565), instantly transforming the Pacific into a vital space of contact and exchange (Conquering the Pacific: An Unknown Mariner and the Final Great Voyage of the Age of Discovery--Houghton Mifflin Harcourt, 2021). These days I am researching the fallout from that venture. Just as Columbus's voyages triggered a major transfer of plants, animals, and germs across the Atlantic, so did the opening of the Pacific created a biological corridor across the largest ocean on Earth with very significant but little-understood consequences for the world.