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The immune system is one of the reasons why I stopped believing in large scale evolution. I still believe small scale evolution exists, but I do not believe tha

The immune system is one of the reasons why I stopped believing in large scale evolution. I still believe small scale evolution exists, but I do not believe that our immune system came about randomly. There are two main factors to our immune system that protect us: 1) all our cells are marked uniquely and exactly the same across every cell in our body. Every human, and I think every animal, has this same feature where all cells are marked the same. But unless there was an immune system to enforce this, it has no value. If it were random you would expect every cell to be marked randomly but it’s not. 2) our immune system is designed to attack anything that isn’t marked with that unique identification. If we had random identification per cell, the immune system we have couldn’t be created. This system couldn’t be designed separately. It’s essentially a single transaction two-step evolution that simply couldn’t have been done randomly at different points in time. If you created an immune system that attacked things that weren’t marked the cell across all cells, the organism would die because the immune system would attack itself the way transplant patients would. The immune system we have couldn’t be created unless all the cells were marked the same. Both parts (unique identification are the same across all cells, and the immune system that attacks any other things that aren’t marked the same) must have been created at the same time. If anyone has any counter arguments I would love to hear it because I’ve been thinking about this long and hard during Covid and couldn’t think of anything else.

Drakim 4y ago
Usually when there is a two-step process needed for something to evolve, then there is often an advantage to one of the steps in isolation that isn't easily apparent, or the advantage it gave might have been lost to time.
flobosg 4y ago
Note that there are two different types of immune systems: innate and adaptive, which work together to protect against pathogens. It seems that you are conflating both.
AdrianB1 4y ago
"came about randomly" is a strange statement; natural selection, where you filter out weaker specimens of the species in favor of the stronger ones is not random, it is a long time process.
- the-printer 4y ago
  I don’t necessarily follow everything that the parent comment is covering, but I gather that he may be referring to the sheer existence of the immune system. How can natural selection account for that?
  - fernandopj 4y ago
    You're making the same mistake as the OP: looking in isolation at the current, final step of a process that took millions of years. Also, you're gonna find a lot of different immune systems in nature, just as you can find many different eyes/vision in animals. There's a lot of middle ground in species that saw no advantage in evolving that particular system against their environment. You're also confusing the randomness of the steps with the somewhat previsible trend of an entire ecosystem which is evolving. If world is getting warmer and air more dense, you wouldn't be able to guess which mutation occurs but you can predict in time animals would be more adapt to that new ecosystem. Darwin famously looked at a unusual orchid with a long "tube" leading to nectar, and spoke that "there must be a bird with a long beak here somewhere". He didn't find it at first, but it was discovered later [1]. So you can apply some predictions at how evolution took place if you take a look at the environment. Just as one would guess there must be an immune system in animals if you discover diseases, virus, bacteria etc - or else how would large animals exist? [1]https://laidbackgardener.blog/2017/04/12/darwins-orchid https://laidbackgardener.blog/2017/04/12/darwins-orchid
  - pazimzadeh 4y ago
    There is no "immune system." There is an innate immune system which reacts quickly but only to general threat patterns (kind of like racial profiling, to be crude). It is really easy to explain the evolution of this system. The adaptive immune system is the one that runs a mini-evolution within your own body as way to counter the extremely rapid rate of evolution in pathogens. There are a few explanations as to how this came about - see my last comment. Paradoxically, it may be the very success of our immune system which puts selective pressure on pathogens to evolve even faster. The acquired immune system: a vantage from beneath https://pubmed.ncbi.nlm.nih.gov/15539148/ https://pubmed.ncbi.nlm.nih.gov/15539148/
mrkeen 4y ago
> I stopped believing in large scale evolution. I still believe small scale evolution exists It's always been small scale, the whole time. Otherwise you'd have the bizarre discontinuities that people like to straw-man evolution with. Like a fish that just decides to walk out of the ocean and breathe air one day.
1auralynn 4y ago
You're not understanding the timescale or the context of the immune system's evolution. Imagine a cluster of unicellular organisms forming a multicellular organism for the first time. A multicellular organism stands a much better chance of survival than a single cell. Imagine a mutation that resulted in a cell surface protein that indicated cells were "friendly" and maybe even allowed them to glom together. Later on, a billion or so years later after the system of cell surface proteins have grown in complexity, imagine a multicellular organism like a sponge, where the ocean flows freely through the inner compartment, helped along by simple differentiated cells containing primitive cilia/flagella. Some of the cells that line the wall of the inner compartment become proto-macrophages, capable of "eating" foreign objects that flow through. The context here is that the immune system has deep ties with the digestive system evolutionarily. So, a ton of the functionality of the immune system has an overlap with the digestive system... "self vs not self" goes way back.
meindnoch 4y ago
The cells of an organism can have attributes that are: 1. unique to each individual cell 2. unique to the organism, but identical among its cells (i.e. cells descending from the same egg cell) 3. identical among all members of the species, or even across species Any immune system will necessarily evolve to use the attributes from group #2. If it were to use #1, the organism dies. If it were to use #3, then rogue cells from other compatible organisms can infiltrate and steal the organism’s resources, which is evolutionarily disadvantageous (unless it’s a beneficial relationship, c.f. gut microbiome).
deleted 4y ago
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pvg 4y ago
This argument is 'irreducible complexity' from Intelligent Design, a pseudoscientific attempt to shoehorn creationism back into science education. https://en.wikipedia.org/wiki/Irreducible_complexity https://en.wikipedia.org/wiki/Irreducible_complexity is a good starting point, of course you can also just google 'intelligent design' and go from there.
- yarg 4y ago
  Dawkins invalidating the notion that the eye is irreducably complex: https://www.youtube.com/watch?v=Nwew5gHoh3E https://www.youtube.com/watch?v=Nwew5gHoh3E. Showing quite clearly how incremental beneficial change leads to the development of complex features. But it will never matter to creationists: https://creation.com/the-design-of-tears-an-example-of-irreducible-complexity https://creation.com/the-design-of-tears-an-example-of-irred.... (Don't even bother with that last link.) They'll always just build another straw man.
stevenhuang 4y ago
I think you need to learn more about the immune system. But to continue your analogy, it doesn't need to be a two-step process. You can start with an immune system and "randomly marked" cells (they're not random, but say they are). Millions of cells are created by your body every second. The cells that are marked "incorrectly" will die off, leaving those the immune system recognizes to continue reproducing. Overtime the remaining cells DNA will only contain instructions to create new cells "marked" to not provoke an immune response. Why is one such counterexample so unthinkable a process to you?
- deleted 4y ago
  [deleted]
- remote_phone 4y ago
  No because the immune system would have to know to rely on the fact that the markings are different across every single cell in the body. Until they were all exactly the same, the immune system couldn’t switch over to relying on this. Entire organs not just cells would die. It needs changes in two separate systems, the cellular system and the immune system, and it has to occur randomly.
  - stevenhuang 4y ago
    > because the immune system would have to know to rely on the fact that the markings are different across every single cell in the body You are confused because you are looking at the final result and not how the system came about. The two systems can be randomly initialized and it will all converge together to a working system over time. And again one can bet it's not really random, aspects of DNA "initialization" happen even before gestation (mitosis) phase. And then during fetus growth all of this can still be developed independently and converge over time. I am speaking from a layman's perspective and even I can surmise many such counterexamples that may explain how the immune system came to be. I again reiterate that you seem to be operating on an incomplete understanding of not just the immune system, but how evolution and embryonic development works. You may want to read this: https://www.nature.com/articles/s41390-022-01940-0 https://www.nature.com/articles/s41390-022-01940-0 > The initiation of hematopoiesis from the yolk sac of human embryo, formation of the bone marrow, and all the immune cells produced from it begins at 5 weeks of gestation, which stimulate mass production of immune cells in the following weeks to boost the immune system
pazimzadeh 4y ago
The fact that each of our cells has an identical unique marker (you must be referring to the MHC?) is not the basis of how the immune system functions. Instead, during development in the thymus, lymphocytes carrying a wide variety of unique immune receptors are exposed to proteins from all over your body (heart protein, lung protein, etc..) and any lymphocyte that reacts with self is killed (negative selection), thus leaving you with remaining cells which which do not react to your body. https://en.wikipedia.org/wiki/Autoimmune_regulator https://en.wikipedia.org/wiki/Autoimmune_regulator The fact that the MHC regions is so diverse is just another layer of security which prevents major biases within the population in the presentation of chopped up bits of foreign and self antigens. However if we all had the same MHC, the function of the adaptive immune system would remain intact. Plus, we would be able to transplant organs between people much more easily. The basis for the existence of these varied adaptive immune receptors which perform the recognition of self vs non-self is under investigation and you might want to read up on the latest research before jumping to conclusions: https://europepmc.org/article/pmc/6084782 https://europepmc.org/article/pmc/6084782 If I remember correctly though, one of the major hypotheses is that an ancestor of the HIV or similar virus or transposon integrated itself within the gametes of some jawed fish without killing it, resulting in the ability to generate variation in immune receptors. https://pubmed.ncbi.nlm.nih.gov/7584143/ https://pubmed.ncbi.nlm.nih.gov/7584143/ Oh, and there is not just one way to have an adaptive immune system, as even jawless fish have a way of rearranging their receptors to generate diversity: https://pubmed.ncbi.nlm.nih.gov/15241406/ https://pubmed.ncbi.nlm.nih.gov/15241406/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3805090/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3805090/ In sum, the only GOD we have evidence for around in the Generation of Diversity. https://www.nature.com/articles/430157a https://www.nature.com/articles/430157a

Drakim 4y ago

Usually when there is a two-step process needed for something to evolve, then there is often an advantage to one of the steps in isolation that isn't easily apparent, or the advantage it gave might have been lost to time.

flobosg 4y ago

Note that there are two different types of immune systems: innate and adaptive, which work together to protect against pathogens. It seems that you are conflating both.

AdrianB1 4y ago

"came about randomly" is a strange statement; natural selection, where you filter out weaker specimens of the species in favor of the stronger ones is not random, it is a long time process.

the-printer 4y ago
I don’t necessarily follow everything that the parent comment is covering, but I gather that he may be referring to the sheer existence of the immune system. How can natural selection account for that?
- fernandopj 4y ago
  You're making the same mistake as the OP: looking in isolation at the current, final step of a process that took millions of years. Also, you're gonna find a lot of different immune systems in nature, just as you can find many different eyes/vision in animals. There's a lot of middle ground in species that saw no advantage in evolving that particular system against their environment. You're also confusing the randomness of the steps with the somewhat previsible trend of an entire ecosystem which is evolving. If world is getting warmer and air more dense, you wouldn't be able to guess which mutation occurs but you can predict in time animals would be more adapt to that new ecosystem. Darwin famously looked at a unusual orchid with a long "tube" leading to nectar, and spoke that "there must be a bird with a long beak here somewhere". He didn't find it at first, but it was discovered later [1]. So you can apply some predictions at how evolution took place if you take a look at the environment. Just as one would guess there must be an immune system in animals if you discover diseases, virus, bacteria etc - or else how would large animals exist? [1]https://laidbackgardener.blog/2017/04/12/darwins-orchid https://laidbackgardener.blog/2017/04/12/darwins-orchid
- pazimzadeh 4y ago
  There is no "immune system." There is an innate immune system which reacts quickly but only to general threat patterns (kind of like racial profiling, to be crude). It is really easy to explain the evolution of this system. The adaptive immune system is the one that runs a mini-evolution within your own body as way to counter the extremely rapid rate of evolution in pathogens. There are a few explanations as to how this came about - see my last comment. Paradoxically, it may be the very success of our immune system which puts selective pressure on pathogens to evolve even faster. The acquired immune system: a vantage from beneath https://pubmed.ncbi.nlm.nih.gov/15539148/ https://pubmed.ncbi.nlm.nih.gov/15539148/

mrkeen 4y ago

> I stopped believing in large scale evolution. I still believe small scale evolution exists It's always been small scale, the whole time. Otherwise you'd have the bizarre discontinuities that people like to straw-man evolution with. Like a fish that just decides to walk out of the ocean and breathe air one day.

1auralynn 4y ago

You're not understanding the timescale or the context of the immune system's evolution. Imagine a cluster of unicellular organisms forming a multicellular organism for the first time. A multicellular organism stands a much better chance of survival than a single cell. Imagine a mutation that resulted in a cell surface protein that indicated cells were "friendly" and maybe even allowed them to glom together. Later on, a billion or so years later after the system of cell surface proteins have grown in complexity, imagine a multicellular organism like a sponge, where the ocean flows freely through the inner compartment, helped along by simple differentiated cells containing primitive cilia/flagella. Some of the cells that line the wall of the inner compartment become proto-macrophages, capable of "eating" foreign objects that flow through. The context here is that the immune system has deep ties with the digestive system evolutionarily. So, a ton of the functionality of the immune system has an overlap with the digestive system... "self vs not self" goes way back.

meindnoch 4y ago

The cells of an organism can have attributes that are: 1. unique to each individual cell 2. unique to the organism, but identical among its cells (i.e. cells descending from the same egg cell) 3. identical among all members of the species, or even across species Any immune system will necessarily evolve to use the attributes from group #2. If it were to use #1, the organism dies. If it were to use #3, then rogue cells from other compatible organisms can infiltrate and steal the organism’s resources, which is evolutionarily disadvantageous (unless it’s a beneficial relationship, c.f. gut microbiome).

deleted 4y ago

[deleted]

pvg 4y ago

This argument is 'irreducible complexity' from Intelligent Design, a pseudoscientific attempt to shoehorn creationism back into science education. https://en.wikipedia.org/wiki/Irreducible_complexity https://en.wikipedia.org/wiki/Irreducible_complexity is a good starting point, of course you can also just google 'intelligent design' and go from there.

yarg 4y ago
Dawkins invalidating the notion that the eye is irreducably complex: https://www.youtube.com/watch?v=Nwew5gHoh3E https://www.youtube.com/watch?v=Nwew5gHoh3E. Showing quite clearly how incremental beneficial change leads to the development of complex features. But it will never matter to creationists: https://creation.com/the-design-of-tears-an-example-of-irreducible-complexity https://creation.com/the-design-of-tears-an-example-of-irred.... (Don't even bother with that last link.) They'll always just build another straw man.

stevenhuang 4y ago

I think you need to learn more about the immune system. But to continue your analogy, it doesn't need to be a two-step process. You can start with an immune system and "randomly marked" cells (they're not random, but say they are). Millions of cells are created by your body every second. The cells that are marked "incorrectly" will die off, leaving those the immune system recognizes to continue reproducing. Overtime the remaining cells DNA will only contain instructions to create new cells "marked" to not provoke an immune response. Why is one such counterexample so unthinkable a process to you?

deleted 4y ago
[deleted]
remote_phone 4y ago
No because the immune system would have to know to rely on the fact that the markings are different across every single cell in the body. Until they were all exactly the same, the immune system couldn’t switch over to relying on this. Entire organs not just cells would die. It needs changes in two separate systems, the cellular system and the immune system, and it has to occur randomly.
- stevenhuang 4y ago
  > because the immune system would have to know to rely on the fact that the markings are different across every single cell in the body You are confused because you are looking at the final result and not how the system came about. The two systems can be randomly initialized and it will all converge together to a working system over time. And again one can bet it's not really random, aspects of DNA "initialization" happen even before gestation (mitosis) phase. And then during fetus growth all of this can still be developed independently and converge over time. I am speaking from a layman's perspective and even I can surmise many such counterexamples that may explain how the immune system came to be. I again reiterate that you seem to be operating on an incomplete understanding of not just the immune system, but how evolution and embryonic development works. You may want to read this: https://www.nature.com/articles/s41390-022-01940-0 https://www.nature.com/articles/s41390-022-01940-0 > The initiation of hematopoiesis from the yolk sac of human embryo, formation of the bone marrow, and all the immune cells produced from it begins at 5 weeks of gestation, which stimulate mass production of immune cells in the following weeks to boost the immune system

pazimzadeh 4y ago

The fact that each of our cells has an identical unique marker (you must be referring to the MHC?) is not the basis of how the immune system functions. Instead, during development in the thymus, lymphocytes carrying a wide variety of unique immune receptors are exposed to proteins from all over your body (heart protein, lung protein, etc..) and any lymphocyte that reacts with self is killed (negative selection), thus leaving you with remaining cells which which do not react to your body. https://en.wikipedia.org/wiki/Autoimmune_regulator https://en.wikipedia.org/wiki/Autoimmune_regulator The fact that the MHC regions is so diverse is just another layer of security which prevents major biases within the population in the presentation of chopped up bits of foreign and self antigens. However if we all had the same MHC, the function of the adaptive immune system would remain intact. Plus, we would be able to transplant organs between people much more easily. The basis for the existence of these varied adaptive immune receptors which perform the recognition of self vs non-self is under investigation and you might want to read up on the latest research before jumping to conclusions: https://europepmc.org/article/pmc/6084782 https://europepmc.org/article/pmc/6084782 If I remember correctly though, one of the major hypotheses is that an ancestor of the HIV or similar virus or transposon integrated itself within the gametes of some jawed fish without killing it, resulting in the ability to generate variation in immune receptors. https://pubmed.ncbi.nlm.nih.gov/7584143/ https://pubmed.ncbi.nlm.nih.gov/7584143/ Oh, and there is not just one way to have an adaptive immune system, as even jawless fish have a way of rearranging their receptors to generate diversity: https://pubmed.ncbi.nlm.nih.gov/15241406/ https://pubmed.ncbi.nlm.nih.gov/15241406/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3805090/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3805090/ In sum, the only GOD we have evidence for around in the Generation of Diversity. https://www.nature.com/articles/430157a https://www.nature.com/articles/430157a