Memes

That's reasonable, personally i call upon biology rather than metaphysics. But i believe it directly support your idea.

I think what makes us sometimes too arrogant, morally, is to put to high of a regard for this ideas of consciousness and free will. To the point we stop seeing it as drived by mother nature, as if it was above her.

To be more accurate it's probably more about intelligence, or levels of consciousness. (Because other animals have it too...)

Funny enough i think this moral bias also affect people that supports, respect and love animals too.