archaeal

If you have a simple organism, like an archaeal cell, here's how it goes: The DNA is all one giant circle.

Consequently, eucaryotic cells function broadly similarly to other eucaryotic cells, archaeal cells function broadly similarly to other archaeal cells, and prokaryotic cells function broadly similar to other prokaryotic cells.

The authors suggest this lid domain replaces the conserved Trp that is an Ala in the archaeal enzyme.

Mitochondria went into hiding inside of the reducing environment of an proto-archaeal species and boom - eukaryotes.

In theory, a large DNA virus could take control of a bacterial or archaeal cell.

The article discusses the (highly speculative) hypothesis that eukaryotes arose from a virus merging with an archaeal ancestor to form a nucleus.

The hypothesized RNA self-replicator is far simpler than the 238,000 base pair archaeal genome.

To be clear, this is not the smallest known bacterial genome; only the smallest known archaeal bacterial genome, at 238k base pairs.

Finally, archaeal cells function more closely to eucaryotic cells than do prokaryotic cells.

The first Archae would be the archaeal ancestor.

I worked for a while on extremeophile Archaeal viruses - the type that infect organisms that manage to live in volcanic hot springs, for instance.

'Madly swapping DNA around' happens to this day at the bacterial/archaeal level.

If the hypothesis is false (it is widely believed that eukaryotes arose from a joining of archaea and bacteria, not archaea and virii) then "an archaeal ancestor" doesn't even have a referent.

I believe "archaeal cell" is referring to an Archaea, one of the three branches of life.

Is that the same as the "archaeal ancestor" they're referring to here?

And is the "archaeal ancestor" the same as the "Primitive archael cell" mentioned in the last image in the article?