The problematic part is emboldened.
I can't understand how does the ようになり function here.
Does it mean "With the gradual increase of the life characteristics, the point was reached where an explanation got established"?
I know that ようになる can mean "to reach a certain point", but I don't understand how it works here since it isn't a verb (or is it, and there is an invisible "masu" ending of some sort?).
I found that なり might be an archaic copula, but it would look weird as the text is from Wikipedia.