Fascinating research into the question of how the first eukaryotic cells arose from prokaryote antecedents.

The ancestors of the mitochondria organelles you see today in every cell in your body were once free swimming bacteria, in a world where there were no animals, and no eukaryotic cells. Planet earth then, and for its first 2 billion years, was populated exclusively by bacteria, or single celled organisms. These cells were about one hundredth the size of the cells in your body.

How did life on earth become more complex?

Billions of years before the Cambrian explosion, when the number of animal species exploded into the millions, something much more basic happened at the cellular level. Cells became more complex.

How?

Maybe cells engulfed other cells, and the engulfed cells survived, forming a partnership or a colony.

Or maybe different types of cells hung out in close proximity, in colonies, which eventually merged into a network of DNA exchanging nodes that keep growing in complexity and interdependency.

We don't know.

This new effort to grow and study archea in vitro gives us something to study and experiment with.