also on the Noahs ark thing.. God gave man an additional 120 years from the time he told noah he was going to send a flood, and instead of repenting and turning back to God, the human race went further and further into depravity
also consider this Genesis tells us that fallen angels were having intercourse with humans and producing offsprng that changed the dna basically creating mutants,,
"When men began to multiply on the face of the ground, and daughters were born to them, the sons of God saw that the daughters of men were fair; and they took to wife such of them as they chose. Then the LORD said, 'My spirit shall not abide in man for ever, for he is flesh, but his days shall be a hundred and twenty years.'
"The Nephilim were on the earth in those days, and also afterward, when the sons of God came in to the daughters of men, and they bore children to them. These were the mighty men that were of old, the men of renown. The LORD saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually. And the LORD was sorry that he had made man on the earth, and it grieved him to his heart. So the LORD said, 'I will blot out man whom I have created from the face of the ground, man and beast and creeping things and birds of the air, for I am sorry that I have made them.'
"But Noah found favor [grace] in the eyes of the LORD. These are the generations of Noah. Noah was a righteous man, blameless in his generation; Noah walked with God. And Noah had three sons, Shem, Ham, and Japheth.
"Now the earth was [thoroughly] corrupt in God's sight, and the earth was filled [continually] with violence. And God saw the earth, and behold, it was corrupt; for all flesh had corrupted their way upon the earth." (Genesis 6:1-12)
http://www.ldolphin.org/flood.shtml