I demand an immediate retraction...
"A small mammalian ancestor or two survived the big chill and went on to evolve into us."
I think this is incorrect. Mummy and daddy and that funny over-friendly man from the church who liked me to stay behind after choir practice always told me that we were created from dust and clay by an omnipotent and benevolent higher power. The only possible alternative to this is that we are the descendants of lizard men that came from space just before the tea-time of when those rowdy South American Norte Chicos were getting themselves organised. I think you'll find that both of these are totally legit explanations that would almost stand up to more scrutiny than your ludicrous theory of us all being the descendents of bloody hedgehogs!!!