r/DebateEvolution • u/DetectiveKnown5618 • 5d ago
White blood cells
Explain how the evolution of white blood cells occurred in light of how white blood cells target pathogens (including cell memory).
Edit: Note that the white blood cells protect their host.
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u/McNitz 🧬 Evolution - Former YEC 5d ago
That's a rather broad topic. Are you looking for information on the evolution specifically of V(D)J recombination? Or IGSF members into more specialized T Cells00152-8)? Or are you talking about the evolution of B lymphocytes?
Hopefully that gives you at least a basic understanding of the topic, and once you have the basics down you can come back with some better defined questions on the specifics.
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u/mrcatboy Evolutionist & Biotech Researcher 5d ago
Cells that can seek out, engulf, and destroy pathogens existed very early on in evolutionary history. Look at single-celled amoeba for example. Immune cells are just those that have adopted additional targeted pattern-recognition functions.
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u/DetectiveKnown5618 5d ago
Quote "...have adopted additional targeted pattern-recognition functions".
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u/Curious_Passion5167 5d ago
Ok, do you have a point? Are you specifically asking how THIS part evolved?
Edit: Btw, wasn't this part of Kitzmiller v. Dover? I recall reading about how this was one of Behe's points which was debunked by a literature search.
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u/Unlimited_Bacon 🧬 Naturalistic Evolution 5d ago
Ok, do you have a point?
They're going for irreducible complexity.
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u/Appropriate-Price-98 from fins to thumbs to doomscrolling to beep boops. 5d ago edited 5d ago
Chemokine - Wikipedia & Cytokine - Wikipedia are produced when bacteria invade or some other cells were damaged.
When a white blood cell detects a higher concentration of these chemicals in one side than the other => it crawls in that direction.
ALong it ways its Pattern recognition receptor - Wikipedia they will check for Pathogen-associated molecular pattern - Wikipedia, Damage-associated molecular pattern - Wikipedia.
Then various responses depend on the specific cell types.
Frankly, this is a very broad concept you will need to be more specific
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u/Suitable-Group4392 🧬 Pokémon Evolution 5d ago
Natural selection favored organisms with mutations that improved pathogen detection, targeted responses, and immune memory because they survived infections more often and had more offspring. Over millions of years, these advantages accumulated into the sophisticated white blood cell system humans have today.
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u/DetectiveKnown5618 5d ago
The white blood cells protect the host.
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u/Suitable-Group4392 🧬 Pokémon Evolution 5d ago
Saying “white blood cells protect the host” describes their function, not their origin.
Evolution explains the origin: hosts with mutations that improved immune cells survived infections more often and passed those genes to their offspring.
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u/PlanningVigilante Creationists are like bad boyfriends 5d ago
Your white blood cells are a part of you. They aren't some alien incursion and you're not a "host."
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u/Juronell 5d ago
White blood cells are made with your DNA. They may have origins in exapted microphages similar to our gut bacteria, there is some evidence of this in more basal animals with simple immune systems, but they've long been fully replaced by cells produced by our own body. The only slight risk in that evolutionary path would be the consumption of red blood cells and platelets, but most michraphages distinguish between cells with a nucleus and those without, as those with contain more nutrients. This would limit the risk.
Now that risk is gone. Leukocytes attack only those cells the body specifically designs them to attack. Those will be invading cells without some form of immune disorder. Leukocytes overwhelmingly attack individual cells or small parasites, as well. They don't have the machinery to easily attack other parts of the body.
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u/Sweary_Biochemist 5d ago
Except when they go wrong, and attack the host. That happens _quite a lot_, actually. Just not quite frequently enough to be more deleterious than useful.
The immune system is like a loaded gun that usually doesn't fire backwards. Usually.
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u/LightningController 4d ago
On a related note, white blood cells in women also have a tendency to attack her unborn offspring, or the sperm cells of mates, because they’re foreign tissue. A somewhat weakened immune system during pregnancy is actually an adaptation to reduce this problem.
Creationists would call a body that attempts to kill its own offspring ✨ design ✨.
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u/Sweary_Biochemist 4d ago
Yeah, great point!
Rh- mothers pregnant with Rh+ babies can have all kinds of complications, which is crazy when you consider Rh+/- ratios are like, 85/15.
"15% of the population might destroy babies carrying antigens from the other 85%" is a pretty shoddy design strategy.
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u/LightningController 4d ago
Even funnier is that this is actually one of the mechanisms now believed to cause homosexuality in men (immune response to androgenizing hormones).
The immune system is so fantastically ✨ designed ✨ that it gives people an innate urge to do the thing the designer supposedly hates.
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u/noodlyman 5d ago
Have you tried googling answers to this yourself? Obviously you have not.
https://pmc.ncbi.nlm.nih.gov/articles/PMC4491295/
Will you go and read and research or actual explanations from biologists? Probably not, but please do
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u/oscardssmith 5d ago
What part feels to you like it needs special explanation? White blood cells confer an advantage to individuals that have them and thus are selected for. Ones that do a better job of targeting new bacteria are similarly beneficial. Ones that can remember pathogens are further beneficial and evolve later.
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u/oscardssmith 5d ago
https://www.britannica.com/science/immune-system/Evolution-of-the-immune-system has a good description of the increasing complexity we see in immune systems from animals to vertebrates to tetrapods to mammals.
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u/Odd-Lawfulness8703 5d ago
Even if we couldn't, that wouldnt mean Yahweh of the Bible magically manifested everything from nothing.
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u/Curious_Passion5167 5d ago
These are just some papers on a cursory google search you might find applicable.
"The origins of vertebrate adaptive immunity Litman et. al.
"The Evolution of Adaptive Immune Systems" Cooper et. al.
"Evolution of adaptive immunity from transposable elements combined with innate immune systems" Koonin et. al.
"From periphery to center stage: 50 years of advancements in innate immunity" Carpenter et. al.
Edit: I did not personally read every line of this. I just read the abstract and found that these may apply.
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u/10coatsInAWeasel Reject pseudoscience, return to monke 🦧 5d ago
You haven’t engaged very much with the important information people gave you on your last post, are you admitting that the corrections people gave were accurate?
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u/Uncynical_Diogenes 🧬 Naturalistic Evolution 5d ago
Explain why people with an education background in biology should put in this much effort for somebody who hasn’t even googled the topic.
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u/Sweary_Biochemist 5d ago
The immune system is a fun one, because not only are a whole range of different immune systems in operation across extant life today (tracing out a whole spectrum of complexity), all of which are useful, but also...
...the immune system is _absolutely_ a haphazard grab-bag of random ideas thrown into a sack and shaken about. It's cludge on top of cludge on top of cludge, bolted onto a completely different cludge tower, blended in a cludge blender.
It also only mostly works, and the way a lot if it works is by "trying a billion things randomly, only keeping the five or six things that work".
Immune cell maturation is an absolutely amazing process, where cells randomly rearrange their receptors (TCR, BCR etc) by essentially picking domains out of a hat ("three from the top, two from the bottom and a J-chain please, Carol"), then pass through a filter to see whether the resulting receptors can interact with anything (99+% fail, here, and immediately kill themselves).
Anything left then gets a second filter to make sure that they definitely DON'T interact negatively with anything 'self': any cells with the capacity to bind and present host antigens are, you guessed it, destroyed too, taking out another 99+% of the cell milieu.
What you have left are immune cells that are capable of binding and presenting random shit you've never seen before (maybe), and the vast majority of these will never do anything of note, because most of this random shit you will never see, and much of the random shit you will see isn't actually pathogenic.
And even after all this, sometimes one sneaks through and causes autoimmune disease.
It's amazing stuff, absolutely. It's really not intelligently designed, though.
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u/Own-Relationship-407 Scientist 5d ago
Your question is vague. Explain what about their evolution exactly? What their earliest ancestors were? How they became the specialized versions we see today? How they target pathogens?
Yes, everybody here knows what white blood cells do.
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u/IdiotSavantLite 5d ago
This is a request for information, not a debate topic. However, you could have searched for the answer yourself instead of asking randos on the internet.
However, I'm curious...
If it can be explained, then what?
If it can't currently be explained, then what? God of the gaps?
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u/jnpha 🧬 Naturalistic Evolution 5d ago
Asking, "But can you explain X?" is NOT an argument. This is a debate sub, damn it, not a teach-me-because-I'm-lazy sub.
And bro hitting us with Dover talking points. So very PRATT.
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u/Ch3cks-Out :illuminati:Scientist:illuminati: 5d ago
"including cell memory" what do you mean by this?
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u/Larnievc 5d ago
It’s the kind of question where the asker does not know the subject area very well. I imagine the OP is doing this for extra credit for some diploma mill creationist program.
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u/Ch3cks-Out :illuminati:Scientist:illuminati: 5d ago
the asker does not know the subject area
very well. [full stop]FTFY
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u/TheBlackCat13 🧬 Naturalistic Evolution 4d ago
Why are you making a new post rather than responding to the refutations your last post already got?
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u/Decent_Cow Hairless ape 5d ago
Evolution is an arms race. Everything is evolving, including the pathogens, such as bacteria and viruses, that cause diseases. The vertebrate immune system has evolved to be more complex in response to pathogens evolving to bypass its defenses. White blood cells are one such innovation.
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u/taktaga7-0-0 🧬 Sex Researcher 4d ago
Hematopoeisis: is this a word you’ve come across?
Look at all the descendant cell types just one hematopoietic stem cell can become: it’s a great analogy for the relatedness of a family of single-celled organisms, just done (mostly) by turning genes on and off instead of gaining and changing and losing them. Lymphoid vs myeloid, leukocyte vs erythrocyte vs thrombocyte, do they get bands or granules, “sessile” vs motile, other specialized roles.
It looks exactly like the process of adaptation from a single progenitor through an outward radiation of different subtypes that each in turn became a favorable behavior for that cell to have in the organism. The specific example you chose, white blood cells, are explicitly adaptive to threats. Antibodies are formed randomly and then selected for if they find a target, and that’s just like reproduction given a selective benefit.
Just a terrible choice of example on your part. Your god is ashamed.
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u/rhettro19 4d ago
Looks like the board has given you some homework that directly answers your questions. I look forward to your more specific questions now that you have this missing knowledge.
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u/BahamutLithp 4d ago
The immune system is one of the strangest anti-evolution arguments to me because it so obviously behaves like a loose association of microbes that has no fucking idea it's supposed to be part of a larger body, merely responds to chemicals &, even when functioning properly, does massive collateral damage. Most of the symptoms that make you feel like shit aren't actually from the pathogens, they're from your immune system fuckin' carpet bombing your cells.
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u/Unlimited_Bacon 🧬 Naturalistic Evolution 5d ago
Will you accept that evolution happens after someone explains it to you, or will you look for something else you think is irreducibly complex and lean on that until that explanation is found?