Hell even if they had ladder double helixes the most reasonable explanation would be a laborer did some psychedelics and either blew a priest’s mind with it or decided to incorporate the thing that blew their mind into some detailed work. It’s not difficult structure to imagine while tripping and ancient people sure did trip from time to time.

In general, assume ancient people were on drugs before you assume ancient people had knowledge of the complex structures they didn’t have the tools to observe.