Evidence for primary endosymbosis includes the presence of a double membrane around the chloroplasts; one membrane belonged to the bacterium, and the other to the eukaryote that captured it.
As probas da existencia desta endosimbiose primaria son a presenza dunha dobre membrana arredor dos cloroplastos; unha destas membranas pertence á bacteria, e a outra ao eucariota que a capturou.