Fascinating! Is the way these new groups mess with their genetics different enough from the rest of Earth’s life to require another shift in how we classify them? “What ‘known species’ even means” points to maybe yes, but I’m not versed in genetics and just found out about these groups from your post.
It’s only been, what, 20 or 30 years since our ability to look at genes started really shaking up taxonomy and yielded “the phylogenetic tree.” I wonder what studying these tiny weirdos will teach us about what we still don’t know about our own more stable branches.
One of the groups (DPANN) is I believe invariably symbiotic, which made it hard to find through traditional methods. It may shed light on how eukaryotes got started.
A kind of fascinating problem in microbiology is that prokaryotes didn't take high school science and don't realize you can't acquire traits, you can only inherit them. So they trade genetic material with each other like Pokemon cards in a process called "horizontal gene transfer". This makes it considerably harder to figure out what 'species' even means.
It’s only been, what, 20 or 30 years since our ability to look at genes started really shaking up taxonomy and yielded “the phylogenetic tree.” I wonder what studying these tiny weirdos will teach us about what we still don’t know about our own more stable branches.