Research team discovers 'impossible' unicellular organism

The origin of eukaryotes is considered one of the greatest enigmas in biology: according to current doctrine, two prokaryotes, a so-called Asgard archaeon and a bacterium, are believed to have merged. The bacterium is said to have developed into a mitochondrion. Thanks to its mitochondrion, this eukaryotic ancestor had enough energy available to develop into the more complex cells known today.