Of course I've been up all night! Not because of caffeine, it was insomnia. I couldn't stop thinking about coffee.
When adapting or evolving another creature you may adapt or evolve that creature without having to discard a card.
Is this just once per turn? Other cards specifically say once and this one doesn't. Although it is in the singular so I don't know.
All cards are once per turn. There is a blanket statement early in the rules and Richard has clarified this on the forms.