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Primitive Asgard cells show life on the brink of complexity
- taxerbee1 4y agoA new study published in the journal Nature sheds light on the evolution of complex life from newly discovered "Asgard Cells"! Go science... love the science of evolution, so fascinating! So it seems like these Asgard Cells are complex cells that evolved on Earth over 1.8 billion years ago. These cells have features similar to both bacteria and eukaryotes, which are the two main types of cellular life on Earth. The discovery provides insight into the evolution of eukaryotic cells, which are believed to have originated from a symbiotic relationship between two different types of bacteria. As we go further and further back in time, chemical and biology evolution merges :)
- deleted 4y ago[deleted]
- baremetal 4y agoWhere did the entropy in the genome of any species come from? The data man, where did it come from? When everything in the universe degrades or rusts or tends towards decreasing complexity. Edit: When I say entropy the first time I'm referring to algorithmic information theory entropy, whereas the second indirect reference is to physical entropy.
- meindnoch 4y agoIt came from the energy that the Sun pumps into the system.
- mcphage 4y agoI don't know why so many people forget that the laws of thermodynamics are all about closed systems, which the Earth is very much not.
- baremetal 4y agoI don't know why so many people forget to explain where _the complexity_ comes from and just drive right off the road assuming I don't know something basic and can distract from having to answer the real question about the complexity of the information in DNA and its origins. Not a very generous argument style you have there.
- throwaway173738 4y agoHave you never heard the joke about a million monkeys typing on a million towers eventually producing the complete works of Shakespeare? Little by little variation is accumulated when it’s beneficial, and the organism dies fast when it’s not.
- andrewflnr 4y agoThis is also a bad argument. You probably know very well that if a cryptographer can force you to employ infinite monkeys on typewriters to guess their key, they'll declare victory. You need a mechanism that searches and focuses the space of possible chemistry, that forces life into being. If you look at the timeline for the emergence of life, I don't think it's one that supports an infinite monkey type of mechanism. It was too fast.
- anonymouskimmer 4y agoAs posted in earlier articles and from what I have read: The basic buildings block of our life spontaneously form from the chemistry of the early Earth (our even the chemistry of space). Lipid membranes spontaneously form enclosed structures. This forces molecules together allowing fast and directional catalysis. RNA is directly catalytically active on itself and other molecules. That's just what I can recall. There's more about DNA/RNA and amino acids pairing, but I can't remember it off the top of my head.
- andrewflnr 4y ago
- kevviiinn 4y agoAnd the energy from within the earth through geothermal vents
- baremetal 4y agoI understand we aren't a closed system. But that still doesn't explain to me where the complexity came from.
- causi 4y agoUltimately this question is the question of why the universe isn't completely isotropic in all directions with a completely uniform distribution of matter and energy. To the best of our knowledge this is due to quantum effects at the beginning of time creating a temporary asymmetry whose resulting "sloshing" created everything more complicated than evenly-distributed hydrogen gas. Life on earth is the tiniest swirl of complexity in the vast waterfall of "wasted" entropy that is the sun burning out.
- evv555 4y ago>Ultimately this question is the question of why the universe isn't completely isotropic in all directions with a completely uniform distribution of matter and energy. I don't think it's a self-evident given that going against the grain of increasing entropy leads to complexity. The obvious but naieve opposite of increasing entropy is going towards something like relatively simple crystal structures.
- baremetal 4y agoThat is rather hand wavy and doesn't explain where the complexity in DNA comes from, you just swept that problem under the rug with a blanket explanation that lacks explanatory power.
- anonymouskimmer 4y agoDNA is actually rather simple. It basically consists of about the fewest number of bases possible for encoding information (four), even though more bases are possible (and have been stably engineered into organisms). Even so, while these bases pair off well, there is some cross-talk possible (G-quadruplexes, G:T base-pairing).
- causi 4y ago
- mromanuk 4y agoLife it's just a cooler way to speed up entropy.
- COGlory 4y agoI would encourage you to find a copy of (it's very expensive, but there are methods to acquire it, such as "libraries") Eugene Koonin's "The Logic of Chance", if this is a topic you're interested in. It basically goes through evolution from a molecular biology and information theory standpoint (and culminates in his own theory of "genesis").
- baremetal 4y agoThank you, you are the only person that actually addressed my point in this thread. I just acquired the book.
- DoctorOetker 4y agoIt seems to be available for download for free? 1st or second hit on google: http://www.evolocus.com/Textbooks/Koonin2011.pdf http://www.evolocus.com/Textbooks/Koonin2011.pdf
- COGlory 4y agoAwesome! It wasn't the last time I checked.
- DoctorOetker 4y agoI remember exploring a "traditional html with images" website about natural selection (I don't think it was interactive, but I do think the source code for each experiment was provided). I assume it was made by a mathematician / physicist. Do you by chance happen to know which site I have in mind? I (vaguely) recall a blueish gray background.
- FeepingCreature 4y agoRandomization plus selection. The big innovation of life is having a form of matter that can quine its own arrangement. Once you have that, the complexity that ensued was predictable.
- Qem 4y agoIt comes from Death's sickle, prunning the random noise introduced by mutations to generate useful information. Natural selection. There's a paper where people put bounds in terms of bits/generation a species can acquire over time. Apparently sex developed as a workaround life found to inclease this bandwidth from about 1 bit/generation to much larger values: http://www.inference.org.uk/mackay/gene.pdf http://www.inference.org.uk/mackay/gene.pdf
- Symmetry 4y agoNot quite, they have features of similar both typical archaea and eukaryotes, but living in close symbiosis with bacteria. We already pretty much knew that eukaryotes came from an archaea/bacteria merger, we're just much closer to figuring out how that happened.
- haxxbro 4y agoImplications for the search for extraterrestrial life! The unusually unique features of the cells suggest that it MAY have evolved elsewhere in the universe.
- deleted 4y ago[deleted]
- anonymouskimmer 4y agoWe're all very much mixed at this point. But think of the other possibility: That the ancestor of the archaea lineage evolved on Earth while the ancestor of the bacterial lineage came from space.
- ch4s3 4y ago> while the ancestor of the bacterial lineage came from space. I don't believe this is supported by evidence. Finding a few organic molecules in a meteorite is pretty thin, and as Carl Sagan pointed out the lethal doses of radiation in space make panspermia highly unlikely.
- anonymouskimmer 4y agoOh sure, this is all wild speculation. It's fun though.
- ch4s3 4y agoThat seems fair, it is an interesting idea.
- dan-robertson 4y agoWhat about the similarity of their dna to other superphyla?
- Kaijo 4y agoThe genomic studies described in the article clearly show the phylogenetic relationship of Asgard archaea to other archaea and thus better resolve their place on Earth's singular tree of life. The excitement is over their potential to resolve the deep branching structure of that tree. They plausibly share a most recent common ancestor with all eukaryotes and in some sense represent an evolutionary grade of transition towards eukaryotes. It's also exciting that some strains have been maintained in pure culture for the first time, so that we can rule out the findings as being merely artefacts of metagenomic sequencing methods. How did you to get aliens from this?
- dav_Oz 4y agoWhile the new evidence/discovery itself can be quickly summarized: >Within the now-dominant two-domain picture to which the Asgard archaea are contributing, the big story of life on this planet goes something like this. Some 4 billion years ago, life forked into two single-celled branches, the archaea and the bacteria. Genetic evidence implies that the two branches crossed again 2 billion years later when an archaeon — likely from the Asgard group — somehow ingested a bacterium. The process domesticated what was once a distinct, free-living cell and turned it into the organelles called mitochondria that persist inside eukaryotic cells. The descendants of that fateful union branched into other single-celled organisms like dinoflagellates, and then later into multicellular creatures that grew to macroscopic sizes, left fossils behind, and colonized both sea and land. What stands out for me the most throughout the article, however, is the hostile environment and over-competitiveness "slowing down" the already painstakingly slow research itself (acknowledged by all parties): >Now a high-stakes, slow-motion race is on as labs around the world attempt to grow their own Asgard cultures. Samples aren’t shared; growth strategies are tightly guarded secrets. “We were honestly shocked” when the Schleper team’s results came out, wrote Hiroyuki Imachi, the microbiologist at the Japan Agency for Marine-Earth Science and Technology who, after a grueling 12-year effort, isolated the first and currently only other Asgard archaea sample. >Meanwhile, in Schleper’s lab in Austria, the initial six-year grant was dwindling and no new funding was in sight. One postdoc assigned to the task of growing the organism had ended up leaving science. Another team member, a technician, had pipetted so much they needed surgery for carpal tunnel syndrome. >Still, labs around the world are gambling that bringing more diverse representatives of the Asgard group into cultivation will yield a bonanza of new clues about their — and our — common ancestor. Schleper is trying. So is Ettema. So is Baum, who said his lab is soon welcoming a new colleague who will bring vials of archaea from groups like Heimdall and Odin. So is Imachi, who declined to speak to Quanta for this story. “If I were to be interviewed by you now, I would most likely talk about new data that has not yet been published,” he explained in an email, adding that his group applauded the Schleper team’s efforts. “It is very competitive now (although I do not like this kind of competition),” he added. Other sources also bemoaned the overly pressurized atmosphere. “It would be nice if the field would be more open to sharing,” Spang said. The pressure weighs heaviest on the young scientists who tend to take on the high-risk, high-reward cultivation projects. Success can add a glowing Nature paper to their resume. But wasting years on a failed effort can stunt their chances of ever getting a job in science. “It’s really an unfair situation,” Schleper said.
- layer8 4y agoThe title gives me Stargate flashbacks.
- 7thaccount 4y agoExcept I doubt their cloned cells would be anything so primitive:)
- beebeepka 4y agoThey perished because of their cloning practices. Clearly they should have asked humans for the sort of help they needed with the replicators. We could've provided plenty of our primitive DNA. Wait, were there any female Asgard?
- deleted 4y ago[deleted]
- Symmetry 4y agoA pretty important piece of evidence on how the first eukaryotes came about. The two big schools of though were previously that symbiosis happened first before they merged or that the bacteria started out as a parasite living inside the archaea before developing symbiosis. The evidence for the later is that the bacterial ancestor of mitochondria seems to have been in the order Rickettsiales which contains the cell parasite that causes Typhus in humans. But seeing a species so similar to the arachea parent of the first eukaryotes in close symbiosis with bacteria seems stronger evidence the other way. It's not quite the classic hydrogen hypothesis[1] symbiosis but it's the similar. [1]https://en.wikipedia.org/wiki/Hydrogen_hypothesis https://en.wikipedia.org/wiki/Hydrogen_hypothesis
- photochemsyn 4y agoMitochondria didn't really become advantageous until free oxygen began to increase... so maybe the chloroplast and oxygenic photosynthesis were the more important developments in terms of the evolution of complex life? Perhaps mitochondria were a key partner to chloroplasts, but I wonder which came first? Or maybe just the free-living chloroplasts were capable of raising oxygen levels, once they'd figured out how to prevent themselves from being oxidized by their own waste products.