Originally Posted by Brother Tim

The necessity is to consider it a possibility, since there is no evidence other than pure speculation*** that something intervened to stop the activity prior to the flood. The age argument doesn't work because that continued past the flood for a number of generations.

*** Of course, the whole angels-mating-with-women is speculation based on a phrase, "sons of God" which we have seen may have several meanings, although NO SCRIPTURE equates the phrase with angels.