"Some studies suggest the "stink" from your groin is actually a vestigial evolutionary byproduct as well."
Really? And all along I thought it was just bacteria.
So now smell is an evolutionary byproduct?
It is when the organism does things to "cultivate" it for some purpose. Like pheremones for example, or the fragrance of flowers which attracts pollinating insects. Or even the horrible stink like rotten corpses from flowers that rely on flies for pollination.