PBS Eons has another new episode.  This time they discuss sponges and how they saved the world to allow more complex life to evolve.

They have survived every catastrophe and every mass extinction event that nature has thrown at them. And by being the little, filter-feeding, water-cleaning creatures that they are, sponges may have saved the world.

Thanks to Franz Anthony and Julio Lacerda for their wonderful illustrations of sponges and snowball earth and other things. You can find more of their work here: https://252mya.com/