User blog comment:MeDeoPal/On the Origin of Titans and Shifters/@comment-24657413-20140904053725

Actuually i hav a better way to explain the origins so ya:

People from this "village at the south" outside the walls are all titan shifters, in case you didnt realize. in fact, that's where annie, Ymir, Berthot and reiner all came from. They probally found those guys and made an injection and gave it to eren. (refer to the scene where eren's father tried to inject him w/ something) those people in the south village probally are the ones who made the formula to create titans, (cause they just appeared out of nowhere 100 years back, it cant b evolution so its an artifact) they injected e thing into themselves n cause them to b titan shifters.

So how do u think my explanation is? pls rply thnx