What explains the symbiotic hypothesis?

The symbiotic hypothesis explains that the middle ancestor of eukaryotic cells that received the epixenosomal apex as protective ectosymbionts later became endosymbiotic. Nevertheless, they nevertheless emerged from the surface of their host in order to fulfill their function. Later, many genes were lost or incorporated into the host genome. Finally, the genome, bacterial membrane, and endosymbiotic vesicular membrane were completely lost, and finger-like projections with microtubules formed.