I think that the Nephilim mentioned in the Torah are kind of a Canaanitic/Israelitish equivalint to the Titans of the Greek traditions; Men of strength and stature, born of the gods, and were heroes of the ancient world before "the flood."
It is known that the name, 'Rpum', has been found in the Ras Shamra tablets of Ugarit which dated to the 1200's bc. These were warrior gods who traveled by chariot to attend feasts of El in Syria.
When the earliest traditions of the Torah were first written down between 900's and 700's bc in the Israelite and Judean courts, the Nephilim and Rephaim were obviously names which envoked the idea of superhumans or gods/demi-gods. The name Rephaim was used to describe ancient heroes and tribes whose mysterious origins and legendary attributes were unrivaled.
Were the Nephilim giants? It seems the Hebrew chroniclers felt that they were, but vaguely so. They used the name "Nephilim", similarly how a Greek would use the word "Titan" to convey an idea of strength and power, and this would coincide with great stature aswell.
How big were these giants? Within some of the ranks of a tribal army, there would undoubtedly have been some big and highly respected warriors who may have even formed special fighting units. If you had several families who had a genetic average stature of 6'to 6'6 for men, and they all served in the same division these men would almost certainly have been feared by a regular platoon of soldiers.
The average stature of the ancient Israelites has been reliably estimated at around 5'5 for men and 5' for women. Since Goliath was 2 meters tall, or about 6 feet 7 (according to DSS)and may have weighed 250 or 300 lbs, this fits quite well with the height range I described.
In 2 samuel 23:21 there is also mention of an Egyptian 5 cubits tall, who was slain by one of David's mighty men. 5 cubits is about seven feet six.
The WWE has atleast six men who could really be considered gigantic even by modern standards: The Great Khali, 7'3 420 lbs, Big Show, 7' 500 lbs, Kane 6'9 326lbs, Undertaker 6'9 320 lbs, and Mark Henry 6'1 400 lbs.
If these modern wrestlers were introduced to the ancient Israelites 3,000 yeears ago, I could almost bet you that legends would be born not unlike those of Goliath.
Acromegaly is a rather rare disease affecting 1 in several thousand people, but Gigantism is far rarer, perhaps affecting 1 in half a million or more. The earth's population at the time of King David was about 70 to 100 million people, and maybe only 300,000 living in Palestine at his time. Yet this does make it statisticaly possible for "pathological" giants to exist in Palestine at the time.
However, the likliest explanation is that these giants described in the bible refer to men who were constitutionally taller than average men, and perhaps a few were affected by gigantism or Acromegaly.
Trying to find archaeological evidence for the Nephilim is about as realistic as trying to find evidence of the Greek Titans, Hercules or any other hero.
Whatever the case, it is evident the Hebrew scribes of around 900 bc retained ancient traditions concerning the tall and mighty warriors who lived in Palestine from the times of Moses to David.
Gath has been identified at Tel es Safi. A pot shard has been discovered with the name "Rpa" inscribed, also more recently a shard has been found here which dates to 900 bc and retains the names "Alwt and Wlt" inscribed. These names are somewhat similar to the name Goliath.
In 1902-1909 At Gezer, RAS Macalister did excavate several male skeletons who ranged in height from 1.8 to 2 meters tall (The average male inhabitant of Gezer was about 1.7 meters)
In 1985 at Tell es-Saidiyeh, Jordan, The British Museum unearthed over half a dozen skeletons of tall men and women ranging from around 1.8 to 2 meters tall who lived around 1200 bc. Some other skeletons in this same height range have been found at Bab Edh-dra near the Dead sea.
In June 1994 it was reported that an underwater tomb was uncovered near Atlit in N. Israel, which contained the body of a 2 meter tall Neolithic man who lived some 8,000 years ago.
In 1979, a first century tomb at Jericho revealed the name "Goliath" inscribed on an ossuary which contained the bones of a man 1.9 meters tall. Evidently Goliath was his nickname, as he would have stood much taller than average men of the time.
As can be seen from just a few of these known archaeological discoveries, there were some ancient people with a genetic stature of 1.8 to 2 meters living in Palestine over a wide range of time, and it can be further extrapolated that there would have been occasional 7 footers among an already tall tribe or family group whose genetic average height is 6' to 6'6 for men.
The common or short cubit was likely the measure which the Hebrew used for everyday measure, the Royal cubit was for priestly or governmental contruction projects and buildings. A common cubit was estimated at about 18 inches give or take a centimeter or two (18" corresponds perfectly to a 5 1/2 ft man; the cubit representing 27-28% of total stature). A span was the distance from thumb to smallest finger, or about 9 inches, half a cubit. Using standard measurements of the day, Goliath was basicaly 2 meters or more in stature: roughly 6'6-6'9, and this probably didn't include his helmet.
Yes, most ancient Semitic male skeletons excavated in Palestine have generally ranged from 5'3 to 5'7 from prehistoric to Roman times, with women about 4 inches shorter. This makes an average of 5'5. Even modern Jewish male populations have been measured by anthropologists through-out the years and the measurements are very much within this same range given geographic distrobution:
SAMARITANS OF PALESTINE: Mediterranean-caucasoid,tall, avg. 173cm [5'8]. JEWS OF PALESTININE C.1915: short stature of 159cm [5'3] and no blondism. JEWS OF NORTH AFRICA: taller than Palestinian Jews, avg. 164-166cm [5'5]. JEWS OF TURKESTAN & AFGHANISTAN: moderate stature of 166cm[5'5] JEWS OF THE CAUCASUS:163-166cm in stature [5'4-5'5]. THE KARAITE JEWS OF THE CRIMEA: 164.5 in stature [5'5]. ASHKENAZIM JEWS OF WESTERN EUROPE: ht varies from 162-167cm [5'4-5'6].
Basicaly my point is that the common male Jew or Semite of ancient and even relatively modern Palestine (and other geographic settings) were generally within the 5 1/2 ft range, give or take an inch. By comparison, a modern white American male is 1.77 meters tall (5'10) on the average according to http://www.halls.md/chart/men-height-w.htm
The relative tallness of Americans is largely because of better nutrition and/or constitutionally taller stature due to genetics. Obviously, as can be seen, there was likely a range of stature to be found throughout the ancient people of Palestine, as movements of caucasoid, semitic, and Amernoid types settled the land.
"If you really want to know the truth about NephilÃ¬m, the 'sons of ElohÃ¬m' and the 'daughters of men' you have to compare the ENTIRE BIBLE (not only Genesis) with the ancient traditions, along with the recent discoveries of extra-long human bones."
That would be a wide interpretation of the Nephilim, spanning not only the mid-east but far and wide.
Extra long human bones can be interpreted as Nephilim in the eye of the beholder. You could then also say that the WWE's Great Khali (7'3 420 lbs) is of the Nephilim, as his stature is similar to alleged giant bone discoveries.
I was suggesting that in a sense, any large giant of a man, modern or ancient, could be considered Nephilim if we use a broad interpretaion.
WWE is America's World Wrestling Entertainment (proffesional wrestling) where they use big men for stunts and pre-arranged matches. Great Khali in metric units would be 2,20 m and 190 kgs, they also have another man named Big Show who is 2,15 m and 225 kgs.