As Utah State joins Pac-12, the conference sued the Mountain West over more than $50 million in poaching fees.

The Pac-12 is suing the Mountain West over what it calls an unlawful and unenforceable “poaching penalty” that would cost more than $40 million.

The dramatic move comes against a Darwinian backdrop in which the Pac-12, decimated by the departure of the 10 universities, is attempting to rebuild with schools from the Mountain West.