It doesn't exist within its own ecosystem, as I mentioned. Stake is derived from work and work itself is a security, ie, your work is secured by prior works. Everything that built it needed prior work and everything to secure it needs prior security, up the ladder you'd have yourself to secure and work for the currency, your community along with its own governance to state level and on and on up the ladder. PoW and PoS both exist within the same ecosystem.