eggs and *****
Some of them were people. According to Buddha, there are six realms of existence for sentient beings: hell, hungry ghosts, animals, humans, jealous gods, and gods. We move through all of them according to our karma, over and over again, until we wake up to our true nature.
In the salty brine of life
Half of each person was an egg(present in mother at her birth) and half were newly manufactured *****. That goes back generation, then down the evolutionary chain, then to the elemental level, we were all start dust.
Souls were floating around, in animals, people, etc.
Nowhere. They didn't exist.