I-yi-yi-yi-yi'm not your stepping stoh-oh-oh-one! (apologies to Mickey, Davey, Peter and Mike)
While the stones to the left may look like a bunch of stepping stones, they are not.
They are rocks that reside in Shark Bay, on the west coast of Australia. Shark Bay is a World Heritage site, in fact. So, if you were to step on those stones, you'd be in trouble.
See, these stones are special stones. They are the reason Shark Bay has been designated a World Heritage site.
They look like regular stones that you may find in tidal pools.
These stones are ALIVE!
No, seriously. They are.
They are called Stromatolites. And, stromatolites are the first type of cooperative colonization that life on earth formed.
About 4 billion years ago, life on Earth had started. We call them Cyanobacteria. Those first life forms are still around, too. They are more commonly referred to as Blue-Green Algae.
Well, these single celled bacterium wandered the ancient seas happily enjoying their new invention. Photosynthesis. Photosynthesis is the process where water molecules are ingested, the Hydrogen is consumed for energy, and Oxygen is expelled as a waste gas. Every green plant you see today still uses Photosynthesis.
For Millions of years, these bacteria happily burped and farted, and farted and burped. It was about all they did.
Until, one day, another form of life appeared. One that found our bacterial friends to be quite tasty.
Well, one of the side effects of Photosynthesis is, the bacteria turned sticky. They found that if enough of them stuck together, they were safe from Mr. Muncher.
And, one side effect of all the sticky bacteria clumping together was, they collected floating detritus and sediments. These formed into a hard, rocky outer shell. Like a bacterial Kinder Egg. Almost. Not really. But sort of.
For 3.5 billion years, these bacteria formed colonies that kept getting bigger and bigger. As the older bacteria died, new bacteria joined the colony, and up the stromatolite grew. Fossils have been found that stood over 100 meters tall.
You remember that I mentioned these little guys were burping and farting, right? Ok. Keep that picture in your head for a little longer.
About 600 million years ago, something called 'The Cambrian Explosion' happened. That's a story for another time. Believe me, you're going to love that one.
But with this explosion came more predators. And, slowly stromatolites started to disappear. It seems it was not always a good idea to bunch up together when there were so many things out there that could eat you.
Today, we have a few secluded salt water locations like Shark Bay, where the water has too high a salt content for anything else to live, and a few fresh water adapted colonies of stromatolites. If you ever get the chance, go see some. If you look closely, you will see the little bubbles from their burps and farts coming to the surface.
If you were paying attention earlier in the post, you'll remember I described Photosynthesis. How a water molecule was ingested, Hydrogen consumed and Oxygen expelled as a waste gas? It turns out, those burps and farts are 100% oxygen. And over the course of approximately 2 billion years, these little guys burped and farted enough to take Earths atmosphere from 0% Oxygen to 21% oxygen.
Without those burps and farts, we wouldn't be here.
So, I lied in an earlier post when I said we inhale 1 litre of ass-gas a day. A good chunk of the oxygen we breathe today is ass-gas. Because Blue-Green Algae is still, to this day, the largest producer of Oxygen on the planet. Just another reason we should be concerned about what we throw in the seas.