1. There were many prokaryote life forms. Some did certain jobs better than others.
2. Oparin's prokaryotes were heterotrophs and autotrophs. The heterotrophs took in materials from outside themselves, and sometimes that included whole prokaryotes
3. Once inside, the prokaryotes were not digested, instead they began to do their old jobs in a new environment, inside a host
4. The new prokaryote host was more successful at surviving because it was more efficient