Fallen angels, which left their former estate, will be around until the general resurrection. In scripture trees symbolize people. The wicked are represented as thorns and thistles. The Bible does not say Eve ate an apple. An apple tree does not have knowled of good and evil.
Fruits sometime refer to parts of the body.
It is scientifically possible for a woman to have twins of two different fathers if both conceptions take place within a few hours of each other. But to implant the devil's seed in the woman whom God had specially formed could bring the downfall of the whole race. The fall of man resulted from the encounter of Eve and the serpent-man. Before Eve was formed, God told Adam not to eat of the forbidden fruit. Eve was beguiled, but Adam knew what he was doing.