2 ms·

Ah, thank you, I was suspicious thinking what are the chances they would just happen to be watching something microscopic when such a rare thing occurs... So,

• tga_d 3y ago
  The article specifically says it likely happened 100 million years ago and that the interesting thing is an organelle that fixes nitrogen. That is a big deal, on the order of photosynthesis. A lack of nitrogen-fixing organisms is an extremely common cause of desertification; e.g., it's why industrial farming requires fertilizer, and a major reason why once a forest is clear-cut you'll only get one more generation of trees.