Cloning was another working solution. By genetically cloning an existing body template, whole star races could hypothetically come here and invade Earth if they wanted.

Cloning was another working solution. By genetically cloning an existing body template, whole star races could hypothetically come here and invade Earth if they wanted. 

If they were technologically savvy enough and had knowledge to work on some level as Founders, they would know how to mass-clone biological life forms. Thus, they could keep lots of bodies in storage here, keeping them dormant, nano-travel back to their home planet and nano-travel back here again and 'wake up' these dormant bodies and get to work. One could speculate that if a star race came here to invade in the physical, they would perhaps genetically engineer a being that is stronger, taller, more muscular, and less likely to succumb in battle -- perhaps a scaly Reptilian, or a flying dragon?