#please ask me questions I love endosymbiosis so much

[idlescience]

So one of my all-time favourite scientific theories is endosymbiosis, because I think it's crazy cool. And there has been some big news in the science community lately because they think they've found a nitroplast!

If you haven't heard the theory before, it basically goes like this. Way back in the day, our ancestor cells did not have mitochondria to produce their energy. Instead, cells would produce energy throughout the cell, pretty inefficiently. Then one cell decided to eat a bacteria, business as usual. Except in this case, the cell ate it wrong and essentially forgot to digest it. So this bacteria kept living in the cell, dividing with it. And after a lot of evolution they became completely dependent on one another. The mitochondria receives compounds from the cell, and creates energy in return.

That's thought to be the first event, but it's not the only one. Plants came about because of endosymbiosis as well. A cell failed to eat a photosynthetic bacterium one day, and boom. Suddenly it can eat sunlight.

Both of these endosymbiotic events are pretty crazy, and pretty rare. Until recently, we only knew of it happening three times in the last 1.5 billion years or so (mitochondria, chloroplasts and the chromatophores of Paulinella). But now scientists are proposing a fourth.

The nitroplast!

Nitrogen fixation is an incredibly important process for the Earth, which involves turning nitrogen from the air into usable nitrogen in soil and water systems. If you've ever used a nitrogen fertilizer on plants, you get why this is an important process.

It's always been considered the domain of bacteria, but now they have found a nitrogen-fixing organelle inside an algae (Braarudosphaera bigelowii), making this event number four! You can see the arrow pointing to it below. Look at these cuties hanging out.

Endosymbiosis is so cool, seriously.