I recently have been reading Jewish interpretations of the Tree of Knowledge.... One of the more compelling views is that the Jewish audience almost automatically interpreted the point of the story , and the discovered knowledge, to be a reference to sex ... which automatically disqualified humanity from immortality because the two combined would be disastrous.
And rather than the completely baffling warning from God that eating the fruit would be deadly... it was a word play which meant eating the fruit (learning about sex) would trigger mortality!
Since eating a fruit from a tree can only be a parable about learning of sex (rather than sex itself), the story loses its literalness.
While at the same time, the connection with Sumerian mythology is strengthened!: the snake deity Ningishzida was not only the deity of wisdom (cunning), it was also the deity of fertility, and was likened to a tree (with snake roots and branches).
One translation for this death's name was "The Good tree"... or, "The Tree of Good [...and Evil]!
The depiction of the tree and the serpent was intended as a simultaneously overlapping symbolic image! Exquisitely clever.