Here's the famous chart of Science' Evolution of Man, showing the line that lead up to Cro-Magnon, and Cro-Magnon was replaced by "Modern Man" who the father of Agriculture (tilling the ground) and the first settlements.
The major difference between Cro Magnon man (40,000-10,000 years ago) is that Cro Magnon did not farm. He was the prehistoric "cave man," nomadic, hunter/gatherers.
Agriculture which enabled man to create settlements, began in Mesopotamia, around 10,000 years ago, the same is described in Genesis 2:5: "...and there was not a man to till the ground.") with the creation of Adam, Agriculture began to flourish and spread throughout the ancient world, and strong emphasis is on how not a man existed, to "till the ground". How that became "no man existed," was through fundamentalists' denial of Paleontology and the fossil record of human evolution.
How ironic, that instead of "denying the Bible," scientists were merely doing the will of God, to explain the mystery of Genesis.
"Tilling the ground," is emphasized and re-emphasized. Many Atheists raised the question, "Where did Mrs. Cain come from?" after Cain fled following the murder of his brother. Cro-Magnon had a heavy population throughout parts of Europe and the ancient near east. That is where "Mrs Cain" came from. It is written, (Genesis 4:11) that God greviously cursed Cain, who was a tiller of the ground,
"...And now art thou cursed from the earth, which hath opened her mouth to receive thy brother's blood from thy hand; When thou tillest the ground, it shall not henceforth yield unto thee her strength; a fugitive and a vagabond shalt thou be in the earth."
How interesting that Cain expressed fear about every man who found him would want to kill him? How odd, if the only man living at the time, aside of his dead brother, were his father Adam. Obviously, it is implied that other men were living at the time, including cro magnon women, from whom Cain took a wife.
"And there were giants in those days..."
Many of these ancient people stood 6 ft. tall on average. The video documentary mentions Ancient Chinese scrolls and cave paintings of figures of "great height" that lend credence to the accounts
(see this video snip on the Silk Road Mummies, from National Geographic, "Mummies: Voices of the Dead" (available on video tape.)
Who the "Sons of God" are,
"And the LORD God said, "The man has now become like one of us, knowing good and evil. He must not be allowed to reach out his hand and take also from the tree of life and eat, and live forever."
~ Genesis 3:22
Please take note that God mentions nothing of "fallen angels," "demons," or otherwise. The wicked ones in discussion who plundered the "daughters of men," were man... men... modern man, Adam, a son of God, hand-crafted from the earth, by God himself. Adam was the "fallen one," if you please, and "...they bare children to them, the same became mighty men which were of old, men of renown."
There were giants in the earth in those days; and also after that, when the 1) sons of God came in unto the 2) daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
The verse is speaking of none other than the ancient Cro-Magnon man, ["men of old"] or "ancient man" which had existed from approximately 40,000-10,000 years ago, and through interbreeding, was replaced by modern man.
Now that age old question, "Who Was Mrs. Cain?" is answered. A question often asked by those Atheists, whom were reciprocated with their parents being asked not to bring their children back to Sunday School, because they "asked too many questions." That, requested by Sunday School teachers who simply didn't know how to answer simple questions, due to their ignorance about the human fossil record and denial of evolution and science... and what is written in their own Bible. But perhaps that is due to, more often than not, a failure to actually read their Bibles.