Geological history of oxygen
Alright kiddo, you know how we need air to breathe, right? And we breathe in oxygen from the air to keep our bodies working properly. Well, the Earth wasn't always full of oxygen like it is now.
A really long time ago, about 3.5 billion years ago, the Earth was covered in water and there was no oxygen in the air. Tiny little organisms called blue-green algae (or cyanobacteria) started to show up in the water. These algae were special because they were able to use energy from the sun to turn carbon dioxide and water into food (we call this photosynthesis).
As the blue-green algae started doing this, they were also releasing oxygen as a waste product. But at first, the oxygen they released was taken up by other things in the water, like iron and sulfur. It wasn't until about 2.5 billion years ago that there was finally enough oxygen in the air to breathe.
But even then, there wasn't as much oxygen in the air as there is now. It took a really long time for the oxygen levels to increase to what they are now. This increase happened because more and more organisms started using oxygen to breathe, and because there were more things on land, like plants and trees, that were also releasing oxygen.
So, that's the geological history of oxygen in a nutshell, kiddo. It all started with tiny blue-green algae in the water, and now we have lots and lots of oxygen in the air that we can breathe. Cool, huh?
A really long time ago, about 3.5 billion years ago, the Earth was covered in water and there was no oxygen in the air. Tiny little organisms called blue-green algae (or cyanobacteria) started to show up in the water. These algae were special because they were able to use energy from the sun to turn carbon dioxide and water into food (we call this photosynthesis).
As the blue-green algae started doing this, they were also releasing oxygen as a waste product. But at first, the oxygen they released was taken up by other things in the water, like iron and sulfur. It wasn't until about 2.5 billion years ago that there was finally enough oxygen in the air to breathe.
But even then, there wasn't as much oxygen in the air as there is now. It took a really long time for the oxygen levels to increase to what they are now. This increase happened because more and more organisms started using oxygen to breathe, and because there were more things on land, like plants and trees, that were also releasing oxygen.
So, that's the geological history of oxygen in a nutshell, kiddo. It all started with tiny blue-green algae in the water, and now we have lots and lots of oxygen in the air that we can breathe. Cool, huh?