Were the Nephilim sterile?
That would explain why they were so cranky.
The Bible writers didn't know anything about genetics either - so anyone who had gigantism may have automatically been viewed as originating from the Nephilim. The traits would not be evident until at least later childhood when normal teenage growth spurts would have been vastly accelerated. If I remember correctly, wasn't Goliath reputed to be from the Nephilim as well? Also, IIRC the Bible reports him to have had 6 fingers on each hand, and six toes on each foot - obviously a genetic anomaly. Maybe it means that one of Noah's sons and daughters-in-law carried the traits for these genetic anomalies and Jehovah™ somehow missed it when he was wiping out all the earth's badness with the Flood. (Say it ain't so! )
Notice the medical features of gigantism (from eMedicine.com):
History: The presentation of patients with gigantism is usually dramatic, unlike the insidious onset of acromegaly in adults.
- Longitudinal growth acceleration secondary to GH excess is the cardinal clinical feature of gigantism.
- Tumor mass may cause headaches, visual changes due to optic nerve compression, and hypopituitarism. [May explain why Goliath was unable to dodge the rocks David slung at him, moreso than Jehovah™ directing the stones to its ultimate target.]
- A common finding in GH excess is hyperprolactinemia, which presents in childhood (67% in 1 study) because mammosomatotrophs are the most common type of GH-secreting cells involved in childhood gigantism. [I know guys would be especially cranky about having lactating breasts, especially when they appear to be so big and strong - but imagine the torture these people would have to endure in an age when people were ignorant of the causes and ascribed all abnormalities to demon possession or being cursed by God?]
Physical: All growth parameters are affected, although not necessarily symmetrically. Over time, GH excess is characterized by progressive cosmetic disfigurement and systemic organ manifestations. Physical manifestations include the following:
- Tall stature
- Mild-to-moderate obesity (common)
- Macrocephaly (may precede linear growth)
- Soft-tissue hypertrophy
- Exaggerated growth of the hands and feet with thick fingers and toes
- Coarse facial features
- Frontal bossing
- Osteoarthritis (a late feature of GH excess)
- Peripheral neuropathies (ie, carpel tunnel syndrome)
- Cardiovascular disease (eg, cardiac hypertrophy, hypertension, left ventricular hypertrophy) if GH excess is prolonged
- Benign tumors including uterine myomas, prostatic hypertrophy, colon polyps, and skin tags frequent in acromegaly, with documentation of overall prevalence of malignancies in patients with acromegaly remaining controversial [possibility of impaired reproductive function]
- Frequently associated endocrinopathies including hypogonadism, diabetes and/or decreased glucose tolerance, and hyperprolactinemia [also indicative of impaired reproductive function]