How was the first yogurt made?

Question

I went on a spiral of homemade yogurt videos. But what I noticed was the common step in all of these videos is to add a dollop of existing yogurt to inoculate the new one. But how was the original yogurt made? Please explain. Thank you!

In: 159

Answer 1

Off topic but is it yoghurt or yogurt?
I’m not a native English speaker so this confuses me.