One is pretty much the same as another stromatolite, to my eye. That probably gets the stromatolite biologists in a fury, I suspect... - Nick Lane

That's why they [viruses] are not in the tree of life. They don't relate in a very direct way. ...[T]he tree of life now is not only about ribosomes. You can build trees from whole genomes, but viral genomes? They don't really fit in, in a way which makes sense to people.

In bacteria, the DNA forms into a long and twisted loop. The contorted tracks... close... to form a singular circular . In eukaryotic cells, there are usually a number of different chromosomes... each has two separate ends.

[B]acteria, the simplest of cells, are... so complex that we still have almost everything to learn about their invisible organization.