By doing a few simple calculations, we can conclude that hundreds of millions, possibly even billions, of people populated the Earth by the year of the Flood. In Genesis 6:1, we find that man had multiplied on the face of the Earth. From the time Adam was created until the Flood, 1,656 years had elapsed. (Adding the age at which each man listed in the genealogies in Genesis 5 had his firstborn, plus the 100 years between the age Noah was at the birth of his sons and his age when the Flood began,