The entire story behind the Garden of Eden is really a metaphor for the original state of life before humanity evolved into the modern homosexual sapiens and cultivated it into their own means of comfort. There's no fact in what's written in biblical text. But rather, an offering of an idea of how things begin through simplistic nature. And then, we've discovered that life is far more complex than that, as well as the flaw in a story where there were early homosexual sapiens, which is strange and inconsistent with human evolution.
Plus, just recently, it was discovered that
modern man actually descended from one particular man in Africa about 135,000 years ago. So your friend and his Mormon belief is inconsistent with actual discovery.
That and the fact that we are all stardust.