what if one of Adam's descendants married an ape? 
Oh wait .. they could have married the "sons of God". 
Genesis 6:
When people began to multiply on the face of the ground, and
daughters were born to them, 2the sons of God saw that they were
fair; and they took wives for themselves of all that they chose.
3Then the Lord said, My spirit shall not abide* in mortals for
ever, for they are flesh; their days shall be one hundred and
twenty years. 4The Nephilim were on the earth in those daysand
also afterwardswhen the sons of God went in to the daughters of
humans, who bore children to them. These were the heroes that were
of old, warriors of renown.
