How the placenta evolved from an ancient virus (2020) • Hacker News Board

Re: How the placenta evolved from an ancient virus (2020)

#61

Post by afavour » Sun, Jan 21, 2024, 5:49 AM UTC

nostrademons wrote: post #41

jmyeet wrote: post #28

Earlier quoted context omitted.

Here'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…

I suspect a lot of the "woe, things are way harder for Millennials than past generations, I'm too poor to have a family" zeitgeist is actually this phenomena + literal survivorship bias. Every single person alive today came from parents that successfully reproduced. When you're a kid, it's very natural to think that having kids and a family of your own is the default state of being. After all, all of your friends hav…

Why would any of that be specific to millennials, though? The way you’re describing it nothing would have changed in a very long time.

I’m pretty sure the “I’m too poor to have a family” perspective stems directly from the wild increases we’ve see in the price of housing and not a whole lot else.

Re: How the placenta evolved from an ancient virus (2020)

#62

Post by TravisCooper » Sun, Jan 21, 2024, 5:50 AM UTC

InSteady wrote: post #57

TravisCooper wrote: post #47

Earlier quoted context omitted.

[flagged]

>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…

[flagged]

Re: How the placenta evolved from an ancient virus (2020)

#63

Post by zpeti » Sun, Jan 21, 2024, 5:52 AM UTC

vlovich123 wrote: post #58

lo_zamoyski wrote: post #49

Earlier quoted context omitted.

The OP was making an observation. But I'll bite. First, human beings are not bees or ants. Our nature vis-a-vis reproduction is quite different. Most human beings do reproduce as that is our nature, or certainly most of us used to with the exception of periods of social collapse (think of Rome). We're in that sort of condition now, where we are having little or no children in the developed world. This does not bode w…

No humans aren’t bees or ants. We’re social animals and you can’t ignore society and culture as aspects of evolution. Regardless, you’ve taken this whole thing in a weird direction bringing up a demographic collapse that is a fringe theory at the moment. As for that hypothesis, there’s no actual indication that humanity is in any danger of a collapse just because the boomer generation is passing and our numbers retur…

> demographic collapse that is a fringe theory at the moment

Show me the actual numbers where this isn't a massive change in humanity in the future?

This is not a fringe theory. The effects of the collapse we can theorise on, but the collapse will happen now. It's not a question or a theory.

Re: How the placenta evolved from an ancient virus (2020)

#64

Post by zpeti » Sun, Jan 21, 2024, 5:54 AM UTC

ARandomerDude wrote: post #53

lo_zamoyski wrote: post #49

Earlier quoted context omitted.

The OP was making an observation. But I'll bite. First, human beings are not bees or ants. Our nature vis-a-vis reproduction is quite different. Most human beings do reproduce as that is our nature, or certainly most of us used to with the exception of periods of social collapse (think of Rome). We're in that sort of condition now, where we are having little or no children in the developed world. This does not bode w…

> Furthermore, our society demonizes families, especially large families (perhaps in part stemming from Protestant attempts to restrict Catholic populations in the US) I think it has a lot more to do with feminism than any Protestant/Catholic divide. In the Protestant church I attend, having 6+ kids is pretty normal. Certainly many evangelicals don’t value large families but I think they’re getting that mindset from…

Some say feminism (and progressivism) is just an offshoot of protestantism, albeit a secular, puritan version.

Re: How the placenta evolved from an ancient virus (2020)

#65

Post by deadbeeves » Sun, Jan 21, 2024, 5:59 AM UTC

TravisCooper wrote: post #59

InSteady wrote: post #57

Earlier quoted context omitted.

>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…

This is absolutely untrue. It's strange that an uncoordinated, random walk of mutations would keep a profound number of changes in tact, ready for some other random bit to take place and it all just "fall into place". The eye didn't evolve. Hearing didn't evolve. Smell didn't evolve. These explanations are always full of "must have" and "must have been". This line of thinking is just hopeful projections of desired ca…

>It's strange that [...]

An appeal to incredulity is not an argument.

>These explanations are always full of "must have" and "must have been".

Any explanation that starts with "must have" requires that there is a single theoretical framework that could possibly apply to the world as we see it today. Since you reject this necessity, you must think there's an alternative framework that accounts for all observed phenomena (or that accounts at least as well as the theory of evolution). What is that framework?

Re: How the placenta evolved from an ancient virus (2020)

#66

Post by deadbeeves » Sun, Jan 21, 2024, 6:13 AM UTC

dirtyhippiefree wrote: post #44

Think 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. J…

I 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.

Re: How the placenta evolved from an ancient virus (2020)

#67

Post by [deleted] » Sun, Jan 21, 2024, 6:18 AM UTC

omeid2 wrote: post #11

ta8645 wrote: post #6

Earlier quoted context omitted.

It'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 remin…

> 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".

[deleted]

Re: How the placenta evolved from an ancient virus (2020)

#68

Post by mrphoebs » Sun, Jan 21, 2024, 6:20 AM UTC

TravisCooper wrote: post #55

MrVandemar wrote: post #27

Earlier quoted context omitted.

The eye evolved in much the same way, a bit at a time. It didn't just turn up one day. As for the virus/placenta thing, I recall reading a similar thing about wasps, though I couldn't provide any citations, that the method by which a wasp stops the immune system of a host (such as a catepiller) from attacking its eggs/larvae is viral in origin, and remarkably similar in some ways to the way a mother's body doesn't at…

Strange that an uncoordinated, random walk of mutations would keep a profound number of changes in tact, ready for some other random bit to take place and it all just "fall into place". The eye didn't evolve. Hearing didn't evolve. Smell didn't evolve. This line of thinking is just hopeful projections of desired causality.

The profound number of changes are in tact only if those changes aid in the natural selection of the organism against selection pressure.

Such changes are replicated more successfully (more offspring) making the change/mutation more resilient to disappearing from the genepool.

Over time any organism that's living/thriving is going to have a lot of these mutations stacked on top of one another in a resilient way(size of population with the same mutations). Any mutations that are disadvantageous to natural selection and proliferation are weeded out of the genepool (go extinct)

Re: How the placenta evolved from an ancient virus (2020)

#69

Post by TravisCooper » Sun, Jan 21, 2024, 6:25 AM UTC

deadbeeves wrote: post #65

TravisCooper wrote: post #59

Earlier quoted context omitted.

This is absolutely untrue. It's strange that an uncoordinated, random walk of mutations would keep a profound number of changes in tact, ready for some other random bit to take place and it all just "fall into place". The eye didn't evolve. Hearing didn't evolve. Smell didn't evolve. These explanations are always full of "must have" and "must have been". This line of thinking is just hopeful projections of desired ca…

>It's strange that [...] An appeal to incredulity is not an argument. >These explanations are always full of "must have" and "must have been". Any explanation that starts with "must have" requires that there is a single theoretical framework that could possibly apply to the world as we see it today. Since you reject this necessity, you must think there's an alternative framework that accounts for all observed phenome…

>An appeal to incredulity is not an argument.

It IS strange, using the evolutionary framework itself, that useless mutations will hang around for thousands or millions of years (countless generations) before dropping perfectly into an extremely complex system, that itself is but a small part of a larger complex system.

Evolution teaches that small, immediately useful mutations build upon one another, reinforcing the beneficial nature of the mutation. It's impossible to build large, complex life systems (with a large number of prerequisites at each step) this way. For example, the Heart, Blood Vessels and Blood. They're each extremely complex but useless without the other two.

How would evolution slowly evolve a heart with no blood or blood vessels?

How would evolution slowly evolve blood but no blood vessels or heart?

How would evolution slowly evolve a network of blood vessels but no blood to carry or heart to pump?

Re: How the placenta evolved from an ancient virus (2020)

#70

Post by pitdicker » Sun, Jan 21, 2024, 6:31 AM UTC

> 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?