A pink sponge, photographed at an aquarium today, is not unlike one of the first life forms that appeared in the Precambrian era ... which included sea anemones, corals, and jellyfish, had ...

The Precambrian eon is vast ... and various asteroids -- forms from interstellar gas and dust. Prelude to life (4,550-3,900 mya) Planet Earth is very hot at its formation. As it cools and its ...