The voyages of the early colonial explorers in a sense bridged the oceans. Once isolated continents were brought into contact with each other sharing not only information and culture but biological diversity as well. It is an ongoing process even today, the effects of which we are only beginning to understand. Columbus could never have dreamed how much his "discovery" would change the world.
The introduction of European plants, animals, culture and microbiology totally transformed the Americas. Few traces of what Pre-Columbian life was like exist so complete was this alteration. What is even more amazing is the impact that the New World would have on the Old. Indigenous life, especially native food plants would completely change cultural norms throughout the planet.
The results of this biological exchange still impact us today. The world-wide introduction of non-native species has altered physical and cultural landscapes and altered the world's biodiversity.