Even if the well-known endosymbiotic theory is right, and once free-living single-celled organisms evolved to become organelles within larger cells, much remains unexplained about how, exactly, ...

The endosymbiotic theory, which posits that organelles such as chloroplasts and mitochondria descended from formerly independent cells, has received wide acceptance in the last third of the 20th ...

1.8 billion years ago, a cell ate another cell, but it didn't digest it, and without that happening, we would not exist. This week we explore the origins of eukaryotic cells and ask the question, "Are ...