Two billion years ago, simple cells gave rise to far more complex cells. Biologists have struggled for decades to learn how it happened.
Scientists have long known that there must have been predecessors along the evolutionary road. But to judge from the fossil record, complex cells simply appeared out of nowhere.
The new species, called Prometheoarchaeum, turns out to be just such a transitional form, helping to explain the origins of all animals, plants, fungi — and, of course, humans.
The microbe starts out as a tiny sphere, but over the course of months, it sprouts long, branching tentacles and releases a flotilla of membrane-covered bubbles.
It proved even stranger when the researchers examined the cell’s interior. Dr. [Christa] Schleper and other researchers had expected that Asgard archaea used their eukaryote-like proteins to build some eukaryote-like structures inside their cells. But that’s not what the Japanese team found.
“On the inside, there’s no structure, just DNA and proteins,” said Dr. [Masaru] Nobu.
This finding suggests that the proteins that eukaryotes used to build complex cells started out doing other things, and only later were assigned new jobs.
Read full, original post: This Strange Microbe May Mark One of Life’s Great Leaps