I doubt that the passage "in his own image" was referring to the shape and characteristics of a physical body at all. More likely it was referrring allegorically to the particular form of consciousness that animates us and makes us human.

Likewise, I think Adam is symbolic of the appearance/development of an entire new race of humans rather than being a literal tale about a single man. And Eve is probably symbolic of a new emotional/mental component developing in the consciousness OF that race, not of a single woman.

Not saying I am sure about it. Just saying it seems far more probable than any literal interpretation of the story. I think the story is a parable about the evolution of the human race, and not intended to be taken literally.

It's very ancient. People repeated it and repeated it, and eventually most of them started just taking it literally, because that is the easiest conclusion for most people to come to. It demands no extra thought.

It also delights the skeptics and opponents of religion, being enormously unlikely if taken literally, so they'd rather it wasn't a parable...then they can easily reject it without a moment's hesitation.

The shortest route to anything is the route of least thought about it. The route of instant reaction...either for or against...and no further analysis whatsoever. This is equally true for the literal-minded fundamentalist and the literal-minded skeptic. They have no patience to give consideration to symbols, parables or allegory in ancient religious writings. They don't want to think about it. They just want to declare it "truth" or "falsehood"...and make it their absolute dogma, one way or the other.