Simpler than eukaryotes, but complex compared to bacterial cells, Archaea are single celled microorganisms that are similar to bacteria in size and simplicity of structure but more closely related to Eukaryotes when it comes to molecular organization. They are believed to have evolved before Eukarya and after Bacteria which can be proved by microfossils traces, biomarkers, and more. Archaea at first seemed very similar to Bacteria, and many were categorized as such. Only later was the new domain Archaea suggested. Just like Eukaryotes, Archaea have a nucleus and membrane bound organelles in addition to which they also share many similar features and pathways with humans on the molecular level, such as the enzymes used in transcription and
