Since God created man first and Woman from his rib why does all mankind have nipples. Men can't Breastfeed and there aren't any other unnecessary partss that I can think of.
I know the answer and can provide the answer if nobody else does.
Why is Adam portrayed with a Belly Button?
Here are some contradictions in the Bible. They do not answer the above two questions though.
SAB Contradictions
In the uterus, we all start out as female, in the sixth week, a change occurs and the fetus can become a male and by the ninth week in uterus, that change is complete (most of the time) and the fetus is fully male. Through biological abnormalities, other things can occur, but that is the basics of it.
Why did Adam have a navel? I'm afraid I'll have to stray from religion from this point. We are mammalian. Horses, monkeys, apes, et cetera, give birth with umbilical cords attached. Before we were homo sapiens, we were homo erectus, before that, homo habilis and further back, way down to the lowly pygmy shrew and even more primitive life forms before that. But still, mammalian and umbilical cords. That's the basics of it scientifically.
As for the religious angle, if you're a god and can create the universe and anything in the universe, including all lifeforms and if as an omnipotent being and egocentric, you would of course, create a being to look like you, to satisfy your ego.
The problem with these old religions, is that they were created in an ancient era (even before the dark ages), when humans were extremely superstitious. How superstitious were they? Cheating wives would claim that a god came down and impregnated them, and the superstitious husband's response? "Duh." Okay. Witchcraft and spells? Real as hell to them. Et cetera. Et Cetera.
All of those who believe that every word in their so-called holy book seem to ignore is that humans were around for thousands of years before those scrolls/books and preachings were even conceived and why would a or any deity not bother with them?