You're rignt, Roland, Europeans did, more or less inadvertantly, practice ethnic cleansing on Native Americans. But the reason their diseases were so lethal was not because Europeans were dirty--though they probably were. It was because the indigenous population had had no contact with the disease organisms the Europeans carried, and therefore had no immunity. Measles and small pox were the big killers, along with others. There is some controversy about which direction syphilis was going, there is evidence to suggest it was from N America to Europe. Europeans got a treasure trove of food plants from Native Americans, corn was only one, though the most important. There were potatoes, tomatoes, avocadoes chiles and more. In return the immigrants brought horses, cows, pigs, goats, burros, sheep and chickens. A big reason noone in NA was using the wheel was because they had no draft animals to make it practical. For more on this topic--not very genealogical--read The Columbian Exchange by Alfred W. Crosby, Jr., Greenwood Press, Westport, Conn. 1972. Fran Clark in NM