There are tons of insects with novel endosymbionts. For example, Camponotus ants have some novel endosymbionts - https://pubmed.ncbi.nlm.nih.gov/8866472/ https:

There are tons of insects with novel endosymbionts. For example, Camponotus ants have some novel endosymbionts - https://pubmed.ncbi.nlm.nih.gov/8866472/ https://pubmed.ncbi.nlm.nih.gov/8866472/ . There are even synthetic endosymbionts nowadays (e coli in yeast), and there are cytoplasmic parasites like Wolbachia that you could imagine evolving into an endosymbionts. On the other hand, even if had only occurred 2x, ribosomes occurred 1x - all ribosomes are related to each other and didn’t evolve separately.