Dream on
How the placenta evolved from an ancient virus (2020)
121–130 of 130 posts
Re: How the placenta evolved from an ancient virus (2020)
#122Earlier quoted context omitted.
No "real" evidence? There's plenty of evidence, you just reject it for some reason.
What evidence have you considered to the contrary? Have you ever turned the chessboard around to look at this from the other side of the table? Most people I've spoken to who have strong feelings about this topic have only ever looked at it from one side properly. The GP is skeptical that one can go from A, a chance interaction between two systems, through a continuous uninterrupted, robust, repeatable chain of ungui…
> An organ whose function and elegance is unrivalled by anything we as a species have made with logic and thought.
Before modern medicine, it and the rest of this elegant system had a roughly ~2-3 in 100 chance of killing the mother in any particular pregnancy.
Re: How the placenta evolved from an ancient virus (2020)
#123Cells left behind can make the mother a chimera with out knowing. https://en.m.wikipedia.org/wiki/Chimera_(genetics)
Re: How the placenta evolved from an ancient virus (2020)
#124Earlier quoted context omitted.
I don't believe whether ones finances allowing someone to have children is the factor for whether they will. From my observation (i have not researched this; this is anecdotal), wealthier people opt to have fewer or no kids, and larger families are usually those of lower income, like there's an inverse relationship between wealth and desired number of children. Even I used to want a large family until I acquired a hi…
>wealthier people opt to have fewer or no kids, and larger families are usually those of lower income, like there's an inverse relationship between wealth and desired number of children. I've also noticed this trend, richer societies have less children and poorer societies have more children. Absolutely no politician (aka the people charged with population and demographic concerns) actually points this out, though. P…
Re: How the placenta evolved from an ancient virus (2020)
#125Earlier quoted context omitted.
Sorry 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.
That'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
Going from infecting an organ to getting replicated via meiosis and being transmitted such that it fits neatly into our chromosomes is entirely different things and different pathways. It's impossible. Exogenous viruses affected organs is real and even intertwining in our DNA, like herpes. But the idea that it can create new organs or somehow get into our sperm and egg in order to self propagate into another organism that doesn't have those genes is ridiculous.
Re: How the placenta evolved from an ancient virus (2020)
#126Earlier quoted context omitted.
That'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
Going from infecting an organ to getting replicated via meiosis and being transmitted such that it fits neatly into our chromosomes is entirely different things and different pathways. It's impossible. Exogenous viruses affected organs is real and even intertwining in our DNA, like herpes. But the idea that it can create new organs or somehow get into our sperm and egg in order to self propagate into another organism…
Again, you're arguing against something that wasn't asserted. The article doesn't say some virus infected a human and bam, placenta, next generation. It says some viral infections gave us individual proteins that wound up handy later.
> the idea that it can ... somehow get into our sperm and egg in order to self propagate into another organism... is ridiculous
Again, that's precisely what endrogenous retroviruses do. From my link:
"Rarely, retroviral integration may occur in a germline cell that goes on to develop into a viable organism. This organism will carry the inserted retroviral genome as an integral part of its own genome—an "endogenous" retrovirus (ERV) that may be inherited by its offspring as a novel allele. Many ERVs have persisted in the genome of their hosts for millions of years."
Re: How the placenta evolved from an ancient virus (2020)
#127Earlier quoted context omitted.
> 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.
The person making the claim gets to present the data supporting it. It depends on what you mean by collapse. Is it that population will decline globally for a bit to a new equilibrium point? Sure I can believe that because boomers were a huge population bubble after WWII and there have been lots of living standard advancements since then (a huge one being family planning options being more and more available to the w…
The reason this isn't a doomer Elon Musk theory is that the numbers are very counter intuitive. Add to this the fact that our average age is also rising, hiding the worrying signs even more.
Imagine we have a society with 100 people with a fertility rate of 1, that give birth at 20 and die at 80. Here is how that looks:
---
Year 0: 100 newborns (Population is actually 300 at this point)
Year 20: 100 twenties, 50 newborns
Year 40: 100 forties, 50 twenties, 25 newborns Year 60: 100 sixties, 50 forties, 25 twenties, 12 newborns
Year 80: 50 sixties, 25 forties, 12 twenties, 6 newborns
Year 100: 25 sixties, 12 forties, 6 twenties, 3 newborns
Year 120: 12 sixties, 6 forties, 3 twenties, 1 newborn
within 120 years you've gone from 300 people to 22 people
Korea is worse than this. Japan is close, Europe is getting close. A birth rate of 1 is not impossible worldwide soon.
Re: How the placenta evolved from an ancient virus (2020)
#128Earlier quoted context omitted.
Humans 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 you…
Ants and bees in a hive have very similar genetics. Typically 75%, and sometimes 100%, if I remember. This means that a hive in some ways is best thought of as a single organization, which happens to have a "distributed" body. In that view, the non reproducing individuals are propagating their DNA in the same sense that human liver cells do, even though they don't have the direct involvement that down and egg cells d…
Damn, I need to look out for my phone making up words more!
single organization = single organism down and egg = sperm and egg
Re: How the placenta evolved from an ancient virus (2020)
#129Earlier quoted context omitted.
The person making the claim gets to present the data supporting it. It depends on what you mean by collapse. Is it that population will decline globally for a bit to a new equilibrium point? Sure I can believe that because boomers were a huge population bubble after WWII and there have been lots of living standard advancements since then (a huge one being family planning options being more and more available to the w…
The reason this isn't a doomer Elon Musk theory is that the numbers are very counter intuitive. Add to this the fact that our average age is also rising, hiding the worrying signs even more. Imagine we have a society with 100 people with a fertility rate of 1, that give birth at 20 and die at 80. Here is how that looks: --- Year 0: 100 newborns (Population is actually 300 at this point) Year 20: 100 twenties, 50 newb…
In what world do you imagine a constant fertility rate over a 120 year period? In the 1950s everyone was concerned about overpopulation because it was so high. Now you’re concerned about a collapse because it’s low. It’s a silly fear because it’s a control system with a feedback loop. We’re just not used to seeing it oscillate because we’ve been in exponential growth for a long time, but exponential in nature must plateau and that’s what you’re seeing here.
Also you focus on individual countries and yet worldwide the population keeps increasing.
Re: How the placenta evolved from an ancient virus (2020)
#130Earlier quoted context omitted.
The reason this isn't a doomer Elon Musk theory is that the numbers are very counter intuitive. Add to this the fact that our average age is also rising, hiding the worrying signs even more. Imagine we have a society with 100 people with a fertility rate of 1, that give birth at 20 and die at 80. Here is how that looks: --- Year 0: 100 newborns (Population is actually 300 at this point) Year 20: 100 twenties, 50 newb…
In what world do you imagine a constant fertility rate over a 120 year period? In the 1950s everyone was concerned about overpopulation because it was so high. Now you’re concerned about a collapse because it’s low. It’s a silly fear because it’s a control system with a feedback loop. We’re just not used to seeing it oscillate because we’ve been in exponential growth for a long time, but exponential in nature must pl…
You are making a big assumption about it being cyclical. Never in history have we had contraception, it's a huge change to human behaviour. It's not at all obvious that women actually want more than 1.5 children on average in the west.
We also have tinder etc and a bunch of other changes that are HUGE in terms of culture.
I'm not saying any of these are bad, and there's not way we are going back to no contraceptives. But to ignore the effects of these, ESPECIALLY as birth rates are trending down EVERYWHERE, is pushing your head in the sand.
You are making a lot of assumptions, and as my example shows, if your assumptions are wrong for say ~50 years, you've already made a huge dent in your populations makeup.