While 1492 may have been the year Columbus sailed the ocean blue, it also marks the start of a mass swapping of species between the Old World and the New World as Europe began colonizing the Americas. Research published Wednesday from University College of London (UCL) and Leeds University Professor Simon Lewis and UCL Professor Mark Maslin argues that just over 100 years later -- 1610 -- is when those actions dramatically changed the planet Earth. As a result, they say, 1610 deserves to be designated as the start of the Anthropocene Epoch.