Younger over the Older

I've been noticing over and over in scripture of God choosing the Younger over the older...

EX. Able/Seth over Cain, Shem over Ham, Jacob over Esau, Joseph (and even Judah) over Reuben, Ephefrim over Manassah (Sorry about the spelling) and Daivd over his brothers.

I know the bible speaks of the 1st becoming last and the last becoming 1st, and Romans this theme is addressed some. Then you have the New Covenant of Grace over the Old. Which is still a younger over the older.

So my question is does anyone know of any in depth teachings that cover this theme? Because I'd really like to study this out furhter.

Thanks