You don't have to copy and know every atom before you agree something is like something else. That's just a bad faith argument. Don't look at just the differences look at the similarities, look at how it's able to get so far with such a basic design.

It's like the god of the gaps argument. People who constantly point out that we don't know this hence god, then if you do explain away the phenomenon it's something else. In that way their god is just the gap in our knowledge and is forever shrinking.