It has been said through esoteric teaching that the earth was designated to have 7 root races of approximately 10 billion people. Thus we're are not really over populated - with regular type people that is, but possibly irregular type people that are chronically negative and destructive by nature but that's another blog.
Every soul though unique (with your twin flame) comes from a frequency based on a specific colour or ray - think of it like coming from a spiritual rainbow, these are not though the same colours as our physical rainbow. Each root race came in on one of these rays and presently we are now experiencing souls coming in on the 7th ray - the violet ray - they embody the frequency of 'The seat of the Soul' Chakra.
This system of 7 rays is what was used for visualizing the colours of the Chakras that is used in the creation of the 7 blends of fruits, roots, flowers & leaves.