One tiny mosquito changed history. It bit Alexander the Great, who contracted malaria and died. Had Alex lived 30 more years: There would have been no Roman Empire; Carthage would have lasted 500 more years, the Alexanderan Empire would have directed its attention eastward; Jesus would have lived the same in our timeline, with a Greek-influenced bible, no celibate priests, and possibly no Reformation. Cartheganian ships would have reached the New World maybe 1000 years before Columbus, but the Incas and Mayans would not have been subdued mainly due to gunpowder not being invented yet. The Mayans and Incas surely would have adopted the Old World technology and suddenly would have become powerful forces to be reckoned with throughout the world. There would have been intense competition between the Vikings, Carthagenians and Mayans for control of the area north of present day Mexico.