The origin of eukaryotes is an amazing story. The chances of survival of the original combined organism were 0.0000000001%. All the bacterial RNA and DNA that the bacteria produced during life and death were surely messing up with the archaea inner workings, as bacteria and archaea have different genetic code "dialects". The archea had to evolve a nucleus instantly to keep the bacterial RNA away from it's ribosomes.
The survival of eukaryotes may be so unlikely as to even partially explain Fermi paradox.
The survival of eukaryotes may be so unlikely as to even partially explain Fermi paradox.