This Dead Sea Scroll text from "The Ages of the World" (~100 BC) clearly shows (or at least says) that the angels learned humanity genetic manipulation before the flood of Noah:
"The prophetic interpretation concerning Azazel and the angels who went in to the daughters of man, so that they bore mighty men to them.
And concerning Azazel who taught them to love iniquity and to pass on wickedness as an inheritance..."
From the book "A new translation of the Dead Sea Scrolls", by Michael Wise, p. 269.
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