Another example from our own history.
Ever wondered why the pilgrims landed in Massachusetts rather than further south in the Cheasapeake Bay area?
Because of the cold winters in Mass, there was very little water-born disease. Mass had about one quarter the premature death rate of the areas in the Cheasepeake Bay area and south. The lattitudes where the diseases such as malaria occurred were well known and were avoided.
"Ever wondered why the pilgrims landed in Massachusetts rather than further south in the Cheasapeake Bay area?"
Actually, I read that it was because they ran out of beer. I'll try to find the reference.
Found it! I really do love Google.
This particular day of observance prays for a beer. The Pilgrim Fathers came from Plymouth and Leiden, but they did not have a remotely good time (by Puritan standards) until they reached Massachusetts. They landed there, instead of Virginia, because they had run out of beer and had to stop and brew some more. Why else did you think they thanked God each year for the bension of their new homeland?
http://www.beerhunter.com/documents/19133-001346.html