Microbe With Bizarrely Tiny Genome May Be Evolving Into a Virus (science.org) 23
sciencehabit shares a report from Science.org: The newly discovered microbe provisionally known as Sukunaarchaeum isn't a virus. But like viruses, it seemingly has one purpose: to make more of itself. As far as scientists can tell from its genome -- the only evidence of its existence so far -- it's a parasite that provides nothing to the single-celled creature it calls home. Most of Sukunaarchaeum's mere 189 protein-coding genes are focused on replicating its own genome; it must steal everything else it needs from its host Citharistes regius, a dinoflagellate that lives in ocean waters all over the world. Adding to the mystery of the microbe, some of its sequences identify it as archaeon, a lineage of simple cellular organisms more closely related to complex organisms like us than to bacteria like Escherichia coli.
The discovery of Sukunaarchaeum's bizarrely viruslike way of living, reported last month in a bioRxiv preprint, "challenges the boundaries between cellular life and viruses," says Kate Adamala, a synthetic biologist at the University of Minnesota Twin Cities who was not involved in the work. "This organism might be a fascinating living fossil -- an evolutionary waypoint that managed to hang on." Adamala adds that if Sukunaarchaeum really does represent a microbe on its way to becoming a virus, it could teach scientists about how viruses evolved in the first place. "Most of the greatest transitions in evolution didn't leave a fossil record, making it very difficult to figure out what were the exact steps," she says. "We can poke at existing biochemistry to try to reconstitute the ancestral forms -- or sometimes we get a gift from nature, in the form of a surviving evolutionary intermediate."
What's already clear: Sukunaarchaeum is not alone. When team leader Takuro Nakayama, an evolutionary microbiologist at Tsukuba, and his colleagues sifted through publicly available DNA sequences extracted from seawater all over the world, they found many sequences similar to those of Sukunaarchaeum. "That's when we realized that we had not just found a single strange organism, but had uncovered the first complete genome of a large, previously unknown archaeal lineage," Nakayama says.
The discovery of Sukunaarchaeum's bizarrely viruslike way of living, reported last month in a bioRxiv preprint, "challenges the boundaries between cellular life and viruses," says Kate Adamala, a synthetic biologist at the University of Minnesota Twin Cities who was not involved in the work. "This organism might be a fascinating living fossil -- an evolutionary waypoint that managed to hang on." Adamala adds that if Sukunaarchaeum really does represent a microbe on its way to becoming a virus, it could teach scientists about how viruses evolved in the first place. "Most of the greatest transitions in evolution didn't leave a fossil record, making it very difficult to figure out what were the exact steps," she says. "We can poke at existing biochemistry to try to reconstitute the ancestral forms -- or sometimes we get a gift from nature, in the form of a surviving evolutionary intermediate."
What's already clear: Sukunaarchaeum is not alone. When team leader Takuro Nakayama, an evolutionary microbiologist at Tsukuba, and his colleagues sifted through publicly available DNA sequences extracted from seawater all over the world, they found many sequences similar to those of Sukunaarchaeum. "That's when we realized that we had not just found a single strange organism, but had uncovered the first complete genome of a large, previously unknown archaeal lineage," Nakayama says.
Climate change accelerates evolution (Score:1, Informative)
Climate change accelerates evolutionary pressure, leading to faster mutation rates in pathogens and parasites. We're already seeing this with drug-resistant bacteria thriving in warmer conditions and new disease vectors expanding their range. The agricultural sector will face mounting challenges as parasitic species adapt more rapidly to changing environments, potentially causing widespread crop failures. Combined with weakened ecosystem resilience, this creates a perfect storm for more frequent and severe
Re:Climate change accelerates evolution (Score:5, Interesting)
You may have missed the point. It's not that this archaeum is becoming turning into a virus and some single celled organism needs to hide its wife, hide its daughter. The point is that viruses can come from parasitic archaea as they abandon unnecessary organelles! If this process takes another million years, this discovery will be no less newsworthy.
Re:Climate change accelerates evolution (Score:4, Interesting)
It is interesting. I think a lot of us who did not venture into biology beyond high school or perhaps an undergrad class or two tend to think 'virus first' that is self replicating protein structures came first and then either formed or were formed by our creator into cellular life.
I don't think many of us looking at evolution as a model for how life adapts and changes really imagine something that is an organism going on to abandon that machinery and go back to being just some DNA/RNA strapped to hook. However in the presence of abundant cellular life a virus is really barest solution to existing as a parasite and comes will a lot of advantages, like you can just float there in some saline water not doing anything not requiring any energy etc, quite immune to many chemical conditions that might threaten your metabolic process etc until you 'bump' into a suitable host. So really cellular organisms "evolving" to become virus should be expected.
Re: (Score:2)
Well..."sort of virus first" is probably correct, but that doesn't mean that things don't sometimes go into reverse. The "sort of virus" couldn't be like the current stuff, because it couldn't be parasitic. And there are arguments that a "sort of cell" evolved before the genetic machinery. Nobody really knows, (See "metabolism first" https://ui.adsabs.harvard.edu/... [harvard.edu] for one argument.)
I, personally, suspect that the proto-"cell walls" and the proto-"genetic machinery" evolved their first stages independ
Evidence of direction? (Score:2)
I think a lot of us ... tend to think 'virus first'
Exactly, so what is the evidence that the direction of evolution is from bacterium to virus and not the reverse i.e. a virus that is evolving into a bacterium?
As I understand it both the "virus first" and "virus by regression" models are still though to be viable so if they have clear evidence that the direction of evolution is from bacterium to virus this seems like it would be important to know. However, as far as I can tell the article offers no evidence to support a particular direction of evolution
Re: (Score:2, Informative)
there is no proof humans are changing the climate.
There is also no proof that smoking causes lung disease. But in both cases, there is, as they say in civil court, a preponderance of evidence.
Re: (Score:2)
There is plenty of proof. Claiming there is no proof is like claiming there is no gravity. Simple trolling, no one in the world that does not actively prevent himself from trying to understand that is able to claim the opposite.
Just google 'human made climate change' or ask any AI to research and find proofs for human made climate change and then _read_ it. Just test yourself, or are you afraid you could change your mind?
Re: (Score:3)
or are you afraid you could change your mind?
It's not that they are worried about their mind changing but if climate change is in fact caused by humans that would mean (gasp) the liberals were right about something and if they were right about that what else could they be right about? The conservative alternative media machine simply cannot allow such potentially intrusive and subversive thoughts from occurring at all.
Re: (Score:2)
The only causes of 'Climate change' that are proveably man-made and rectifiable are deforestation and desertification caused by poor ag practices, poor land management, water fuckery.
That's just fake information and lies. If you really believe that, google it and _read_ a few sites if you don't wanna have blood on your hands by actively spreading fud.
Re: (Score:2)
Re: (Score:2)
A whole lot of words I don't understand (Score:1)
what I know about cell biology can be coded in much less than that creature's genome
Degeneration (Score:1)
From Naked Lunch p. 67
Cf Nietzsche
Obligatory: Life, uh Post (Score:2)
Yup, it's all just stardust that's stumbled onto replicating patterns of molecules.
Some patterns are more complex than others, for certain values of complexity.
But like viruses, it seemingly has one purpose (Score:2)
Unlike a bacteria, that have multiple purposes, like also when to pick the kids up from school.
This is an idiotic basis for the distinction between bacteria and viruses. The comments here will be full of more valid distinctions.
Sociopathic Microbe (Score:1)
Evolving into a virus? (Score:3)
It is a big jump to assume it is evolving into a virus.
Why not an organelle?
Note that Candidatus Carsonella ruddii has 182 protein-coding genes.
Wikipedia: "it supplies the host with some essential amino acids. It is therefore probably in the evolutionary process of becoming an organelle, similar to the mitochondria of eukaryotic cells that also evolved from an endosymbiont".
The question is, does Sukunaarchaeum provide the host with any advantage, however incidental?
Given that the authors of the preprint never actually observed the organism, it seems unlikely that they know the answer.
"it seemingly has one purpose: to make (Score:3)
more of itself." Guess what, that is the purpose of ALL LIFE!