yes the great flood ridded us of these half races. and giants were too easy to see and fight with newer ancient weapons and faded into history along with dragons and other monster creatures hunted to extinction.

The passage you are referring to is this one: 1 When men began to increase in number on the earth and daughters were born to them, 2 the sons of God saw that the daughters of men were beautiful, and they married any of them they chose. 3 Then the LORD said, My Spirit will not contend with man for ever, for he is mortal; his days will be a hundred and twenty years. 4 The Nephilim were on the earth in those days— and also afterwards— when the sons of God went to the daughters of men and had children by them. They were the heroes of old, men of renown. ============== It is not an easy passage to understand, and no one has the answer. That being said, there are plenty of theories that have been believed by sincere Christians over the centuries that could be wrong. Traditionally, the line has been taken that "sons of God" meant angels, and "daughters of men" meant human women. This would have resulted in a mix of two creatures. But a thorough study of the Bible reveals that angels do not marry and procreate (Matthew 22:30; Mark 12:25), so this theory, commonly held as it has been, cannot be correct. (Some good bible scholars still hold this theory, saying that, while in heaven, angels may be sexless, on earth, fallen ones may have been different) Another theory was put forward by a group within orthodox Judaism, who theorized that "sons of God" meant "nobles" or "magnates." Hardly anyone today accepts this view. So who are the "sons of God" and the "daughters of men"? Many Bible scholars now hold that the "sons of God" are the male descendants of Seth, and that the "daughters of men" are the female descendants of Cain. According to this view, what actually happened in Genesis 6 was an early example of believers marrying unbelievers. The good sons of Seth married the bad daughters of Cain, and the result of these mixed marriages was a mongrel offspring. These later became known for their decadence and corruption; indeed, it reached such a degree that God was forced to intervene and destroy the human race. This comment of Matthew Henry could be taken as representative of those holding this view: "The sons of Seth (that is the professors of religion) married the daughters of men, that is, those that were profane, and strangers to God and godliness. The posterity of Seth did not keep by themselves, as they ought to have done. They inter- mingled themselves with the excommunicated race of Cain." === Whoever these two groups were, what relationship did they have with the Nephilim, and who were the Nephilim? The Nephilim are believed by many to be the result of the union of these two groups. Traditionally, the word has been translated as "giants", but it may not have anything to do with giants. The word, in Hebrew, may mean “those causing others to fall” (or "killers") and may derive from the fact that they were strong in battle. This goes well with the Biblical statement "They were the heroes of old, men of renown." So they may not have been giants in the sense we know it, but giants on the field of battle. However, there is evidence that they may have been tall in stature as well, which would have terrified the shorter peoples they came up against (in the same way that the Vikings used to terrify the shorter Celts) If so, how tall could they have been? There are three other words that may be related to Nephilim in the Bible, as they refer to very tall people. They are: Emim ("the fearful ones") and Rephaim ("the dead ones")- related tribes, only connected by Jewish tradition to the Nephilim. The Book of Joshua describes one of these Rephaim: The text states that a few Rephaim had survived, one of them being Og, the king of Bashan. Og of Bashan is recorded as having a 13-ft long bed.[11] “ Only Og king of Bashan was left of the remnant of the Rephaites. His bed was made of iron and was more than thirteen feet long and six feet wide. It is still in Rabbah of the Ammonites. Of course, this does not meant that the king himself was that tall, just that his bed was that long. Without doubt, however, he was a big boy, way above modern standards of height. Anakim ("the [long]-necked ones") Wikipedia writes: Anakim are the descendants of Anak, and dwelt in the south of Canaan, in the neighbourhood of Hebron. In the days of Abraham, they inhabited the region afterwards known as Edom and Moab, east of the Jordan river. They are mentioned during the report of the spies about the inhabitants of the land of Canaan. The book of Joshua states that Joshua finally expelled them from the land, excepting a remnant that found a refuge in the cities of Gaza, Gath, and Ashdod. The Philistine giant Goliath, whom David, Samuel 21:19, some translations have brother of Goliath rather than just Goliath, though the latter is more accurate to the masoretic text</ref> later encountered, was supposedly a descendant of the Anakim. “ The land, through which we have gone to spy it out, is a land that devours its inhabitants, and all the people that we saw in it are of great height. And there we saw the Nephilim (the sons of Anak, who come from the Nephilim), and we seemed to ourselves like grasshoppers, and so we seemed to them.[14] ========= (The reaction of the spies was understandable, if they were as tall as Goliath was recorded as being. The calculations of his height range from over 6 feet to over 9 feet. Either was tall by Jewish standards. In the late 1980’s a group of British archaeologists may have uncovered skeletal evidence for giants in Jordan. At the site of Tel es-Sa’idiyeh, archaeologist Jonathan Tubb and a team from the British Museum unearthed the remains of some extremely tall people. I have yet to see this evidence, so I can't confirm it. I hope that more information comes out about it, either pro or con. I hope this answers some of your questions. If I can help any further, just ask.