the colonists were mostly from brazil and mexico , with a smattering from jamaica , barbados , puerto rico , and other caribbean nations , and their natural inclination was to expand south , into the steamy lands near the equator - they were not effete norteamericanos , after all ; they were used to such climates , they knew how to live with the heat , they knew how to farm the jungles , their skins did not sear in the sun .