By Lenny Pierce
If your only association of sponges is our animated friend who lives in a pineapple, you might be a little disappointed with the real thing. Sponges outside of the cartoon world aren’t terribly exciting at first glance. No eyes, no brains, and certainly no pants, square or otherwise – in fact, sponges aren’t much more than towers of filtering organs peacefully pulling nutrients out of the water. Despite their simplicity, these creatures may have played a larger role in the evolution of modern life than anyone would have assumed. In the latest edition of Nature Geoscience, Tim Lenton of the University of Exeter argues that it was these supposedly lowly life forms that allowed the ocean to become oxygenated to the point that it could support a much wider variety of life, including the life forms that would eventually make their way to land.
The logic of this theory lies in the sponge’s feeding process. When sponges first emerged, much of the ocean’s oxygen was being consumed by rotting microbial matter. Luckily, sponges evolved to eat this microbial matter, thus decreasing how much of it was floating around in the water. Lower levels of rotting microbial matter …read more