In terms of size, mammals are an anomaly, as the vast majority of the world's existing species are snail-sized or smaller. It's almost as if, regardless of your kingdom, the smaller your size & the earlier your place on the tree of life, the more critical is your niche on Earth: snails & worms create soil, & blue-green algae create oxygen; mammals seem comparatively dispensable, the result of the random path of evolution over a luxurious amount of time.

Elisabeth Tova Bailey