Well, in practice we don't teach classes in 'how did we get here', at least not science classes. We teach classes in how species arise from other species. I've occasionally taught a class in possible origins for life, but I make sure the students are clear that all theories of abiogenesis are highly speculative. Last time I did it, we even considered 'panspermia' (people have actually done experiments looking at the viability of bacterial spores in interstellar space, etc.)
You can't separate that underlying question "how did we come to be" from any discussion on the origin of species and it is inconsiderate to give agnostics like myself only one side of the story and purposely exclude things from the subject that I may have given some consideration to.
It seems the Darwinists want complete control over our thoughts...and I was always told that's what the religious types wanted.