You learned in the previous section that archaea have ribosomes, similar to eukaryotes. How does this statement support the theory that is presented in the article?

Assuming that this is the theory of endosymbiotic creation of eukaryotes, it supports it by showing that ancient prokaryotes such as archae have ribosomes that could have joined together, as the theory states to create the eukaryote's ribosomes that they have today (because they're so similar.)