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How the placenta evolved from an ancient virus (2020)
- dang 3y agoRelated: How the placenta evolved from an ancient virus - https://news.ycombinator.com/item?id=25655346 https://news.ycombinator.com/item?id=25655346 - Jan 2021 (106 comments)
- ta8645 3y agoIt's a little odd to consider the idea that fighting off modern viruses today, might actually be impeding human evolution in some way we can't foresee.
- AdmiralAsshat 3y agoI suppose the ethical question would be: how many current humans are you willing to let die from exposure to a virus in the hopes that one of them might mutate something useful?
- ta8645 3y agoIt's really an impossible calculation. There's no way to appraise the consequences to assign a value. If it were possible to say, that a future mutation was necessary to save humanity (ie. we are doomed without entering that future) well then perhaps we'd be willing to sacrifice a lot of us now. It's all academic of course, we'll never make such a decision, and never know what could have been. It's just another reminder that we don't really know the future or the best course of action in these situations -- we're just taking our best guess (even the experts).
- omeid2 3y ago> a future mutation was necessary to save humanity Even in that scenario, it is very simple, we protected the people today and use vaccines to induce the necessary mutation. The moral choice in my book is to always err on the side of the living than "potential of the living".
- ta8645 3y agoThat's your personal calculus, and fair enough. World leaders might make a different decision though. For instance, the British military planners allowed soldiers to die on the battlefield, who they could have saved, in order to protect the secret that they had cracked German encryption during WWII. That was a place where the needs of the many, were deemed more valuable than the lives of the few. I'm not judging one way or the other, but it has happened in human history more than once. And in the imaginary scenario where leaders had perfect knowledge of the future, it would likely happen again.
- vlovich123 3y agoThat isn’t as hypothetical a situation though as what you outline which is preventing a mutation now that may be important tens, hundreds of thousands of years or maybe even millions from now. There’s so much time for technology to evolve to make it likely that any negative effects can be countered through that as technology can deal with problems on a much shorter time scale than evolution can.
- omeid2 3y ago> For instance, the British military planners allowed soldiers to die on the battlefield, who they could have saved, in order to protect the secret that they had cracked German encryption during WWII. That was a place where the needs of the many, were deemed more valuable than the lives of the few. This is not a very good comparison, in my opinion. Military is rarely about the "needs of the many" far more than it is about the "powers that be". Once you understand the dynamic at a play, it is rather clear that the soldiers died for what soldiers almost always die for; the regimes that pushes them to war.
- deleted 3y ago[deleted]
- romusha 3y agoThat's the domain of longscamism
- boredgargoyle 3y agoThere are probably thousands (and my guess would be much more) viruses that that dance on the information playground that is our genome, metagenome, and the genomes of the organisms we host. Fighting a few of them is probably not going to be a significant issue. Having more individuals around by itself would also lead to mutations which the environment may select for in the future. By itself there is no such thing as a beneficial mutation (gene import) unless the environment proves it to be.
- ta8645 3y agoYou're really missing the point -- there's no way to know the future. Maybe your optimism is warranted, but maybe we stamped out a virus that would have given us a superpower. The argument is _not_ that we should change our strategy of doing the best we can with the information we have. Just that we should have some humility about what we can and can't actually predict, or say with certainty.
- vlovich123 3y agoOur superpower is developing technology. It’s unlikely evolution could ever outperform that as it operates on much slower time scales for adaptation. So any viral mutation now will only really manifest at population scale after hundreds of thousands of years whereas technology can do it within years or decades.
- ta8645 3y agoYou're doing a lot of work to continue to miss the point. The point is not that we should embrace viruses in order to reap the benefits. Just that it is _POSSIBLE_ that a virus would turn out to be very beneficial to humanity, in the long run. We know this to be a fact, because of the article we're reading above. The only point I'm hoping people will take, is that we shouldn't be so quick to make categorical statements about the future; like we know exactly how things will play out. I don't know for sure. You don't know for sure. The experts don't know for sure.
- pazimzadeh 3y agoYeah, if I remember correctly the RAG recombinases that enable crazy diversity in your B and T cell receptors of your adaptive immune system are also thought to come from a retrovirus that got into our ancestors germ cells.
- badosu 3y agoIt is required some process of natural selection for mutations to be selected against, do we know how this occurs with the modern homo sapiens?
- MrVandemar 3y agoWe have plenty of modern day selection pressure. Watch the first 2 minutes of Idiocracy.
- pfdietz 3y agoUnless you think our ancestral biology is perfectly adapted to the modern world, evolution will be acting. Indeed, evolution is probably occurring on humanity at a breakneck pace right now, because our environment has changed so radically.
- juggertao 3y agoUmbrella Corporation is working on the innovative t-Virus for the next step in human evolution. But people FUD it.
- 6177c40f 3y agoI think the tradeoff is worth it, viruses are far more likely to do us harm than to help us out. Besides, we're entering the age when we can direct our own evolution.
- chasil 3y agoOne way that viral elements are expressed are as transposons. There is even an infectious variant, a gypsy transposon, that can move to neighboring cells. https://en.m.wikipedia.org/wiki/Transposable_element https://en.m.wikipedia.org/wiki/Transposable_element
- hereme888 3y ago[flagged]
- mlcrypto 3y agoKinda morbid thinking about all the failed mutations as laying eggs evolved into the placenta
- jmyeet 3y agoHere's another sobering thought: you represent an unbroken chain from the universal common ancestor of successful reproduction going back billions of years and probably trillions of generations (given that many of those were as a single-celled organism). Every one of those generations a success. So if you fail to reproduce you will break that billion year old chain of evolutionary success. Here's another: you have 2 biological parents, (up to) 4 biological grandparents (go look at Cleopatra's family tree) and so on to an upper bound of 2^n ancestors for the n'th previous generation. At some point this number exceeds the number of organisms that were alive at that time so there are likely one or more individuals in the past who are direct ancestors to everybody. A consequence of this is that if you go forwards in time ultimately your genetic line will either die out or you will be the direct ancestor of everybody given sufficient time.
- vlovich123 3y agoHumans are social animals. It’s myopic I think to only evaluate based on reproduction and genetic propagation. For example, most bees and ants are not involved in reproduction but they are all involved in helping the species survive into the future. So even if you don’t reproduce you have a critical role to play in society (helping it stay cohesive, helping productivity, helping through your work efforts, helping your friends and family raise children who can help humanity survive and be good humans themselves etc)
- mrphoebs 3y agoI doesn't seem like the above commenter was making a value judgement.
- vlovich123 3y ago
- Sakos 3y agoThis seems to be a common thing. We're an amalgamation of different viruses and bacteria that somehow over billions of years coalesced and evolved together into what we are now. I'm never not astounded when I think about it.
- blindriver 3y ago[flagged]
- pfdietz 3y agoYou're assuming it happened all in one go. Instead, the protein was probably inserted into a germ cell by a retrovirus, and then was available in descendants as grist for further evolution, eventually being incorporated into the placenta.
- blindriver 3y ago[flagged]
- starkruzr 3y agoyou are... definitely not a biologist, lol.
- salad-tycoon 3y agoPeople, capable of pondering life’s great mysteries, are going to place faith into something, only difference is if they accept it as a faith or argue their faith into fact. I think this makes many here uncomfortable.
- blindriver 3y agoSorry but I believe in science and evolution, not science fiction. Just making up stories that viruses can create new organs in other organisms and also some get intertwined in the reproduction so that next generations can get the same organs is creationism mythology.
- ceejayoz 3y agoThat's not what the article asserts; you're complaining about a strawman. It asserts that some virus genes made it into our genome, and that some of those were useful in the eventual evolution of the placenta. That mechanism is well documented: https://en.wikipedia.org/wiki/Endogenous_retrovirus https://en.wikipedia.org/wiki/Endogenous_retrovirus
- zakki 3y agoIf every part of a human coming from evolution, how it synchronize between each part? Is there any books explaining evolution in detail? How cell formed? How they found a way to multiply? How they choose DNA to store the information? And so on.
- getoffmycase 3y agoThere is literally a world of biology (text)books that describe the process of evolution and how life came to be. I would recommend finding a syllabus at a local college for a biology class, getting the textbook second hand and then reading it
- taneq 3y agoIt doesn't. Everything that's poorly 'synchronized' just dies out and the more effective organisms keep reproducing. This explains basically everything past the original question of how the original self-replicating chemical reaction started.
- TravisCooper 3y ago[flagged]
- nkrisc 3y ago[flagged]
- thewarpaint 3y agoWhat’s your theory/understanding then?
- rsynnott 3y agoMagic, one assumes.
- InSteady 3y ago>Which came first, the Heart, Blood Vessels or Blood? Which ones were "selected for" before the others arrived? How would a random process, uncoordinated through time select for these things and keep them while they're "not useful" until they are? etc etc Evolutionary biologists have very detailed answers to all of these questions, plus a bunch more that are far more complicated and confounding to laypeople. You can even find some great popular science books that hold your hand and walk you through some of the absolutely mind-boggling ways in which we have found evolution to work. It doesn't require any advanced math courses to wrap your head around if you go at the topic patiently and with an open mind. The numbers and timescales on which evolution has been operating are astronomical, far too large for a human mind to comprehend in any meaningful sense. Of course it's products are also going to be a challenge to comprehend. Especially if you start forming opinions before you have consulted the experts and put in the hard work of trying to learn how those experts know what they think they know.
- TravisCooper 3y ago[flagged]
- dirtyhippiefree 3y agoThink about it. The species that is now Mitochondria was an entirely different species. We carry Mitochondrial DNA, while the human side is Nuclear DNA…nucleus of every cell. Birth as we know it wouldn’t have happened without a third species invading our cells. We know it as placenta. Profound that we fight microbes, but without two (that we know about), our species literally (accurate use) would not exist. At all. Just, wow.
- deadbeeves 3y agoI mean, everything would seem to indicate that mitochondria were assimilated while our ancestors were still microbes themselves. But that aside, our species is the result of everything that happened prior to its appearance, including for example the Cretaceous–Paleogene extinction event. Arguing that we should not attempt to prevent such events (if we're able to) because it would evolutionarily benefit the survivors is suicidal. There's nothing special about our species. If things had happened different would the species that would have been in our place (whatever that means) be better or worse by any metric one chooses? There's no point in wondering about that.
- dirtyhippiefree 3y agoYes, our ancestors were simpler…clearly. We aren’t the only species with the placenta…horses, for example… One species among many.
- pitdicker 3y ago> The syncytiotrophoblast is the outermost layer of the placenta, the part that is pressed against the uterus. It’s literally a layer of cells that have fused together, forming a wall. ... There’s no other structure like this anywhere else in the body.” > When evolutionary biologists like Chuong mapped the genomes of these cells, they found that the protein that allowed these cells to fuse into a wall, called syncytin, didn’t look like it came from human DNA. It looked more like HIV. So the entire premise of the placenta evolving from a virus rests on the fact that the organ has a unique function requiring a unique protein in the body. Saying the source probably is a virus seems quite a leap of thought. And aren't there many highly specialized proteins in the body? Has anybody has some more information on what protein in a retrovirus looks similar to syncytin?
- pitdicker 3y agoPaper that discusses similarities between the envelope glycoprotein of retroviruses and syncytin: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758191/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758191/ This field is called paleovirology, and the paper also discusses in some more detail how fragments of viral DNA can end up in human DNA.
- lifeline82 3y ago[dead]
- ddgflorida 3y agoDream on
- Log_out_ 3y agoCells left behind can make the mother a chimera with out knowing. https://en.m.wikipedia.org/wiki/Chimera_(genetics) https://en.m.wikipedia.org/wiki/Chimera_(genetics)