#1. The first thing I'd like to point out is that people "of great size" does not necessarily mean tall "giant" people.
The term "Nephilim" occurs just twice in the Hebrew Bible, both in the Torah. The first is Genesis 6:1-4, immediately before the Noah's ark story:
... The Nephilim were on the earth in those days—and also afterward—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. ...
The second is Numbers 13:32-33, where the Hebrew spies report that they have seen fearsome giants in Canaan:
And they spread among the Israelites a bad report about the land they had explored. They said, "The land we explored devours those living in it. All the people we saw there are of great size.
We saw the Nephilim there (the descendants of Anak come from the Nephilim). We seemed like grasshoppers in our own eyes, and we looked the same to them."
The reference could refer to strength, not height. Neanderthal men were of great size, and powerful. Even the women were powerful:
"... even Arnold Schwarzenegger at his muscular peak no match for a Neanderthal woman ... Regarding the inadequacy of Schwarzenegger, McAllister studied the remains of "La Ferrassie 2", a Neanderthal lass discovered in a French cave in 1909. She boasted ten per cent more muscle than modern European men, and her upper arm strength was more than enough to "slam him to the table without a problem”. - link
#2. The second point is the location of the sighting mentioned in the bible.
... The Mount Carmel caves outside Haifa set the geographical limits for Neanderthal fossils. One skeleton found buried in the Kebara cave is so well preserved that it has provided the best data yet on Neanderthal anatomy and led scholars to reassess the function of the Neanderthal pelvis and linguistic capabilities, following the discovery of the hyoid bone in the throat. ... - link
The obvious question: Was Kebara Cave, Mt Carmel, Israel in what was known as Canaan? According to this map, Mt. Carmel is very close to Galilee in ancient Israel. And according to worldatlas.com "Israel occupies about 75% of an area long known as Canaan."
Below is a map of Canaan. In what was called Asher, you can see Mt. Carmel where the Neanderthal bones were found. Neanderthal man was in Canaan, and so were the Nephilim!
#3. The third supporting point is that the bible states that some men were descendants of the Nephilim and we now know that Neanderthal man interbred at least twice with Homo sapiens. The bible says, "We saw the Nephilim there (the descendants of Anak come from the Nephilim)." Who was Anak?
Anak ... was a well known figure, and a forefather of the Anakites who have been considered "strong and tall," they were also said to have been a mixed race of giant people, descendants of the Nephilim. ' - wiki
"Using projected rates of genetic mutation and data from the fossil record, the researchers suggest that the interbreeding happened about 60,000 years ago in the eastern Mediterranean and, more recently, about 45,000 years ago in eastern Asia." - nature.com
Yes, Israel (Canaan) is considered to be in the eastern Mediterranean.
#4. Fourth the phrase "The land we explored devours those living in it." and "We seemed like grasshoppers in our own eyes, and we looked the same to them," I think, are references to cannibalism. Having worked with locusts in some of my research, I can definitely tell you that they eat each other. It is revolting. It is something you never forget. This would not have escaped the observation of early men, for whom locusts (super grasshoppers) devouring your crops were one of the worst things that could happen.
We now know from archaeological research that our ancestors ate Neanderthal men.
... fossil expert Fernando Rozzi of Paris's Centre National de la Récherche Scientifique, ... based [the conclusion that we ate Neanderthal men] on a jawbone from a Neanderthal clearly butchered for food by someone with Homo Sapiens tools... - link
Ancient men seemed to be saying, "We are cannibals. We know it, and our food knows it." We ate them!
Did Neanderthal man eat Homo sapiens? Perhaps not. Perhaps the tricky Homo sapiens felt guilt at his behavior and blamed his own "sins" on the enemy he killed and ate. The winners of a war get to rewrite history.
Once the giant Nephilim hybrids were born, these legendary warriors (Titans) of renowned fierceness began to kill off all the humans from the earth. In Numbers 11 we are told that they were not only giants but cannibals as well. The book of Enoch states that they ate the flesh and drank the blood of the people on earth. They were also the number one enemy of Israel."
And I said, Hear, I pray you, O heads of Jacob, and ye princes of the house of Israel; Is it not for you to know judgment? Who hate the good, and love the evil; who pluck off their skin from off them, and their flesh from off their bones; Who also eat the flesh of my people, and flay their skin from off them; and they break their bones, and chop them in pieces, as for the pot, and as flesh within the caldron. Then shall they cry unto the LORD, but he will not hear them: he will even hide his face from them at that time, as they have behaved themselves ill in their doings
In fact, rather than them killing off all of the humans, it was our human ancestors who killed off all of the Titans, if "the Titans" is, as I suspect, another name for Neanderthal. And we at them. I tend to think the book of Enoch is a guilty historical rewrite.
#5. The fifth point of evidence is the fate of Neanderthal and the meaning of the word "Nephilim".
"Nephilim" (נְפִילִים) probably derives from the Hebrew root npl (נָפַל), "to fall" which also includes "to cause to fall" and "to kill, to ruin". The Brown-Driver-Briggs Lexicon gives the meaning as "giants" Robert Baker Girdlestone argued the word comes from the Hiphil causative stem. Adam Clarke took it as passive, "fallen", "apostates". Ronald Hendel states that it is a passive form "ones who have fallen", equivalent grammatically to paqid "one who is appointed" (i.e. overseer), asir, "one who is bound", (i.e. prisoner) etc.
via Nephilim - Wikipedia, the free encyclopedia.
The large powerful Neanderthal men were eventually wiped out. They were the fallen, the ruined, the killed, and it would not be a stretch to believe that they were once made prisoners by their more tricky, more deceptive, better planning Homo sapien cousins. Genesis says, "The Nephilim were on the earth in those days". Now the Nephilim, like the Neanderthal, are no longer on the earth.
Arguments Against the Nephilim being Neanderthal Man
The major problem with my theory, if you accept that "giant" could just mean "a bit taller and much more muscular," is, of course, the timing. Could a story in Genesis really be describing something that happened 60,000 years ago? When did the spies of Israel see the Nephilim in Canaan? One source puts the conquest of Canaan at 1406 to 1399 BC. Another says The Conquest of Canaan by Joshua took 6 years from 1487 to 1493 BC.
The 7 nations that confronted Joshua were GIANTS and they were like the sands of the sea in number. The Lord told Joshua to completely destroy these corrupt nations
Evidence suggests that dates in the bible must be wrong:
A 1401 BC date of the beginning of the conquest is supposed to violate the assured results of archeological findings in Palestine, notably at Ai, Lachish, and Debir. The problem of Ai is indeed acute, if the mound of et Tell is actually the biblical city. Excavation of the site by Mme. Judith Marquet-Krause in 1933 and 1934 has shown that there was an occupational gap in the history of the mound from about 2200 BC until after 1200 BC, so that supposedly there was nothing but a ruin there when Joshua and Israel are said to have captured and destroyed it... - theology.edu
For my theory to hold, the story of the Conquest of Canaan in Genesis would be drawn, in part, on more ancient sources than anyone has so far believed. Genesis, fantastically, may tell of the defeat of the last Neanderthals who survived as late as up to 24,000 years ago.
After wandering in the wilderness for 40 years, Moses handed over leadership to Joshua, whose responsibility it was to bring the nation of Israel into the promised land of Canaan. After entering Canaan, Joshua had to go to war with the people who occupied the land. - link
Perhaps Neanderthal man was around in the time of Moses, but there is, so far, no evidence for Neanderthal being around after 24,000 years ago. Another possibility is that an older story was woven into the real Conquest of Canaan.
Neanderthals, prehistoric cousins of humans, ate grains and vegetables as well as meat, cooking them over fire in the same way homo sapiens did. ... The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for around 170,000 years but all evidence of them disappears some 28,000 years ago, their last known refuge being Gibraltar. Why they died out is a matter of debate, because they co-existed alongside modern man. - physorg
Neanderthal died out because they were out planned and because they were not deceptive cannibals like "modern" man.