Human Hive

[terrycloth]

Nope.
Normally hivemind pops can not exist outside of hivemind empires and vice versa. The proper genetic engineering (2nd ascesion path perk) allows you to add or remove that trait. To assimilate/de-assimilate species.

Well, if you can put it on all your pops with the ascension perk, and then switch civics before they die, it *sounds* like it should be possible.

Oh wait, it's an ethic not a civic. So there would need to be a 'hive mind' faction to embrace. Hee!

You might not be able to save all your pops if you have too many aliens. Depends how long the purge timer is.

 

[The Founder]

You might not be able to save all your pops if you have too many aliens. Depends how long the purge timer is.

For non-hivemind pops in Hiveminds it is "Food Processing" purge hardcoded.
No idea about the other way around, but it will propably be something hardcoded too.