It says that they don't have mitochondrial DNA anymore, and that they can survive in very low oxygen environments....but neither of those is the same as "not needing oxygen". Parasites lose a lot of machinery that they use the host for (such as digestive tracts).<p>Not needing oxygen would mean a pretty dramatic shift in a whole lot of biochemistry. Maybe that's exactly what has happened, but from this article, it sounds more like they evolved to tolerate very low oxygen, and also they use the host for a lot of necessary functions (common in parasites) and so have lost some unnecessary complexity.
There have been plenty of eukaryotes found earlier, including multicellular metazoans (animals), with anaerobic metabolisms. They have organelles called hydrogenosomes, which are thought to have convergently evolved from mitochondria. So, I call bullshit on the title.<p><a href="https://en.wikipedia.org/wiki/Hydrogenosome" rel="nofollow">https://en.wikipedia.org/wiki/Hydrogenosome</a>
The cnidarians are a really interesting part of the animal kingdom. They “break all three rules”, like having single-celled animals, animals that are supposedly “immortal” if nothing kills them (certain jellyfish), and now this.<p>I could see one of them becoming the next humans if we wipe ourselves out.
As noted in the article, the discovery is from 2020: <a href="https://english.tau.ac.il/news/no_oxygen" rel="nofollow">https://english.tau.ac.il/news/no_oxygen</a><p>Funny that this article from 21 June 2024 is the one finally gaining traction.
Most people don’t know that there are species that can, e.g. drop their metabolic rate down to .01% of baseline to survive without water or food for 30 yrs. Or survive in high radiation environments, or high pressure and temperature environments. More people should know that there is genetic precedent for crazy phenotypes that could theoretically extend to other species in the future.<p><a href="https://en.m.wikipedia.org/wiki/Tardigrade" rel="nofollow">https://en.m.wikipedia.org/wiki/Tardigrade</a>
Original paper (2020):<p><a href="https://www.pnas.org/doi/10.1073/pnas.1909907117" rel="nofollow">https://www.pnas.org/doi/10.1073/pnas.1909907117</a>
> The research was published in PNAS<p>Between this and the images I realize that I can still be mentally 12 at times.<p>By ditching the need for oxygen I wonder what these critters use for energy? I'd imagine their parasitism is related...
"no one wants to buy salmon riddled with tiny weird jellyfish"<p>A really interesting article, but I'm not sure if that statement above is really universaly true.<p>In Japan they'd probably make sushi out of them... 8-)
<i>>"In 2020, scientists discovered a jellyfish-like parasite [common salmon parasite called Henneguya salminicola] that doesn't have a mitochondrial genome – the first multicellular organism ever found with such an absence. That means it doesn't breathe; in fact, it lives its life completely free of oxygen dependency. [...] It's a cnidarian, belonging to the same phylum as corals, jellyfish, and anemones. Although the cysts it creates in the fish's flesh are unsightly, the parasites are not harmful, and will live with the salmon for its entire life cycle.
Tucked away inside its host, the tiny cnidarian can survive quite hypoxic [oxygen deficient] conditions."</i><p>This sounds like a very interesting <i>candidate organism</i> to bring to <i>Mars</i> in the future...
Um, are my eyes deceiving me, or did I read e.g.<p>* "Multicellular life needs oxygen to live."
* "They break down oxygen to produce a molecule called adenosine triphosphate..."
Why do we keep acting like we know what the requirements for life are? Those we look to for insight on this are most entrenched in socially accepted fallacies - oxygen is required, carbon is required, water is required.. and based on what evidence? We have a sample size of one - Earth. It's laughable that we're therefore so committed to defining requirements for life.<p>We don't really understand the mechanism that spawns life, so we can't say we understand its requirements.