They didn't delete it. Go to the github diff they reference and check. It's still there. They just removed it from one of the JSON files but people here aren't actually checking facts, they're just jumping on the hate train.
There's a lot of stuff that does something after we thought it didn't. I don't quite trust folk when they say "Oh, that's just there in your body but it doesn't do anything."
I get that some stuff genuinely doesn't because evolution deprecated it, but others we might not yet understand well enough to know this for sure.
My favorite – this is to some degree my interpretation though! – my favorite is the default mode network, a kind of constellation of brain activity.
It’s called the default mode network because they found it through magnetic resonance imaging or something like this, and this activity pattern was the first pattern they saw!… A-ha! This is the default mode network! The default! The default mode! Yes!… the activity pattern in the brain of a human who has been persuaded to go into a very tight-fitting tube and is there all alone and it’s not pleasant.
The default mode is activated during introspection and social isolation and among the things it does is generate the sensation of being something which is distinctly not part of the rest of the world.
I'm not one to typically have strong fear/anxiety responses in situations that aren't actually dangerous. However, I felt extremely uncomfortable being partially inserted into an MRI tube for a lower body scan. I couldn't imagine being shoved head first into that thing without being heavily sedated or completely knocked out.
The thought crossed my mind, to be sure! I talked about all that with the techs beforehand. "Are you sure this isn't going to yank my teeth out?" "Pretty sure. Now stop moving around."
I have a simple hiatal hernia. One of the treatment options is to basically put a weighted band around your esophagus above the stomach so that the weight holds everything downward so your stomach doesn't get pulled up through the hernia. I imagined being in a car accident or some other situation where I'm nonresponsive, the doctor ordering an MRI, and me re-enacting the scene from Alien. Nah, I'll take my chances with the hernia, thanks.
Well - if it helps any - my understanding is that a doctor at an ER center would order a CT scan which is based on x-rays and can be done in a matter of a few minutes.
MRI scans are really reserved for things that don't image well on CT scans or when the resolution of a CT scan just isn't good enough. They also take quite a bit of time to perform.
During my MSc I spent a total of more than 25 hours being scanned in an MRI machine for a study investigating the neurobiology of reading, and by the end of the study I was so relaxed in there that my main problem was not falling asleep because I was lying down with repetitive noises around me!
Could be a million things you subconsciously notice.
* the warning signage
* things that are related to the lead shielding (micro changes in gravity, smell of lead salts, ...)
* infrasound caused by the machinery
* people waiting for an x-ray around who are less-than-happy...
The problem with this kind of thing is that it is often highly individual, and barely, if all measurable with our current scientific instruments. Some people keep claiming that humans are incapable of even hearing infrasound, or sense gravity, claiming anyone who can sense them is spreading new-age esoteric nonsense or is mentally ill. See also: Electrosensitivity.
I'm not saying these things do or do not exist, just that it is in the realm of possibility.
I wouldn't worry much as an X-ray recipient. There was talk in the 1950s about the trade off of getting a routine chest X-ray, say to check if you have pneumonia if you see your doc about a respiratory infection, vs a hypothetical risk of cancer.
so I wouldn't be afraid to get one. The radiology technician though needs to take special precautions because they are around it all day. Personally I would avoid a CAT scan if it were feasible
The mandatory shielding around these rooms is robust. I shadowed a technician inspecting a newly fitted x-ray room and observed the very sensitive equipment used to verify absence of leakage. There was a small puncture in the lead shielding that was quickly found and resulted in a delay until patched.
I don't know what you mean by "around" but if you mean walking down the hallway outside the x-ray room, my guess it's the low frequency sound these machines often produce that you're reacting to and not x-rays themselves. Not to mention the almost sci-fi signage alerting your brain to danger.
And inside the shielding envelope, modern x-ray equipment is still at very low levels unless you're the patient (and even as the patient, imaging requires much lower levels than in the past).
Nah, energy is way too low. If they emitted enough for you to feel it you'd be dead in a week.
I certainly felt my last MRI though. New machine, so probably high powered. Abdominal/liver MRI. Every time the RF was on I could feel a gentle warmth throughout my midsection. Weird but cool.
Humans cannot feel x-rays in the dosages you'd experience in an x-ray room. A sufficiently powerful x-ray would feel hot the same way a bright light does.
I don't really mind medical procedures like that. The time I got punched at Elephant Butte Lake and got stitches at the emergency room I went into a deeply relaxed state that scared the nurse because she thought I'd fallen asleep. Even the noise of an MRI machine is not that startling if you know it is coming.
Indeed. I have a brain tumor (not cancerous and controlled by medication) and for a few years after diagnosis I had to get MRI's every few months for the first year, then one every year for a few years. It was a bit nerve wracking the first couple times but now I can fall asleep in those machines lol.
it’s not the first nor the last time wish that communities would not refrain from changing terminology. fitness is as important as accuracy and we shouldn’t be wary of dropping such inaccuracies, especially when they bring such strong connotations.
they dropped the "nuclear" bit because it is scary, it doesn't involve any ionizing radiation. It is all about making the nucleus wobble but not about splitting atoms. I have fond memories of doing NMR experiments in senior labs as a physics major.
On the theme: The phrase "junk" DNA always irritated me. I'm glad it is being replaced with "non-coding".
Anybody who has looked at a 4kb demo can intuit that "junk" code likely has a function, even if it isn't immediately obvious machine code for the host CPU. I'm no geneticist, and I understand cells aren't CPUs, but I've read enough to know there's at least a tenuous analogy to non-coding DNA and the kind of "junk" you might find reversing a 4kb demo that procedurally generates its output.
Yup, DNA turned out to not merely be a sequence of triplets telling a dumb matter printer which hard-coded proteins to make - at least according to what little I understand of evolutionary developmental biology[0], DNA is much more like procedural generation in gamedev or demoscene. That is, there's plenty of recipes for various structures and body parts, and then there's lots of DNA that's responsible for conditionally enabling or disabling or modulating those recipes, depending on more DNA that controls when and where and how much to enable them, and then more - a complex network of logic.
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[0] - Didn't get much further than this four-minute intro to the field, but it is a good intro: https://youtu.be/ydqReeTV_vk.
(EDIT: It's actually the second part of a trio, that starts with a four-minute bottom-up overview of organic chemistry[1], and ends on a three-minute intro to nanotechnology[2]. I recommend the series together for how well it frames humans in relation to other life and universe as a whole.)
There’s also epigenetics with mechanisms like histone modification and DNA methylation that can control expression without changing the DNA, but still being heritable.
Only the first one is DNA, and only a small portion of 'coding' DNA was initially regarded as important.
My question is how? Structural organization implies information. Who thought "Nah, evolution put that in for shits and giggles"? Was it just things we couldn't observe at all without modern scanning electron micrography?
More to the point, there is still chromosome structure when the cell is normal mode, expressing proteins instead of replicating itself. It's just it is spread apart, probably like a pop-up book where "pages" will snap open and become accessible for transcription as part of gene regulation and other times will be folded up so genes in that section aren't expressed.
Some of the reason it is tough to make GMO products that are really effective is that it's not enough to put a gene in and have it expressed a little, you want to have it expressed a lot. For instance the first version of Golden Rice produced Vitamin A but not enough to matter, it took several years to make one that expressed the genes strongly enough that it made significant amounts of Vitamin A.
> Was it just things we couldn't observe at all without modern scanning electron micrography?
Perhaps also that we couldn't imagine, much less accept, that a dumb semi-random process tweaking bits could, over time, organize those bits into higher level abstract structures. We still mostly talk about evolution mutating genes, where perhaps if you zoom out a little, it's actually working at a higher level of abstraction.
Incidentally, this is the same outlook as some people have today wrt. LLMs - they can't accept the idea that backprop running on a blob of weights representing a simple (if large) graph can start encoding increasingly high-level, abstract organizational structures.
Can't observe and woefully hard to understand. Remember in the 1950's the only genetic disease they could trace to a mutation was sickle cell and that was guesswork. They didn't have any of the cute editing techniques or amplification and sequencing tools. It's a miracle they figured out what they did.
so the thing that makes this complicated is that having non-coding DNA that does nothing for an individual can still be helpful for a population. they essentially serve the same purpose as commented out code that is really common when devs aren't using version control. the comments won't affect the program as it currently exists at all, but they make it so small changes to the code can more easily change the functionality.
Maybe not as much commented as unused. Turns out, there's plenty of that in DNA, and you can force turning it on. See e.g. the bit about snakes growing legs in the video I linked - they still carry the blueprint for legs in their genome, but have it suppressed.
>> I don't quite trust folk when they say "Oh, that's just there in your body but it doesn't do anything."
If you expand that to "You don't need that" it covers the appendix, spleen, tonsils, wisdom teeth (even incisors can be removed to make room) and probably some other things. I'm in favor of keeping all your parts unless absolutely necessary, as all of these things seem to have at least marginal purpose.
1. They used to yank everyone’s tonsils at any provocation. There was a swing back to trying never to take them. I wish my pediatrician would’ve had mine removed after my nth tonsillitis so I didn’t have to have them out in my 30s. That was fun.
2. Having had an emergency appendectomy, I’m sympathetic to the notion of proactively snipping them any time you happen to be in there anyway. Getting a hernia fixed? Oh hey, let’s grab the appy while we’re at it!
Except the appendix is an important organ. It has a high concentration of immune tissue and supports the immune system in the gut, and it's also a "safe house" for beneficial bacteria in the case of food poisoning or other gut "clearing" events.
It absolutely should not be just nipped out proactively.
Those are all true. However, appendicitis is still the most common abdominal surgery worldwide[0] and lots of people still die of it. It's easy to make the case that someone already undergoing abdominal surgery where the surgeon has ready access to it could have long-term lower health risk by removing it.
If you live in a country with excellent healthcare and you're never far from a hospital, the calculus is a bit different. You'll probably be fine. If you regularly find yourself far away from modern medical clinics, it's easier to defend the idea.
I had appendicitis as a kid. If you've never experienced it, trust me, you don't want it.
If you practice good food safety and hygiene (and live around people who do the same) then removing the appendix during unrelated surgeries or even preemptively before long stays at a place without emergency healthcare can be beneficial.
It's a bit of a Chesterton's Fence situation: the appendix is really useful, but for you and me the benefit was much larger 300 years ago than it is today. Today the benefit is small enough that you can remove it with only minor considerations (like being more cautious about your gut microbiome, and having a slightly worse immune system)
Makes me wonder what we'd uncover with systematic longitudinal studies (within the same culture, rather than comparing populations with distinct cultures and genetic bases) on effects of male genital mutilation.
I would expect at least some evolutionary pressure to get rid of unused things in your body. Let's just take the appendix as an example because it's probably the most common "you don't actually need this" thing that people know about.
Some appendixes burst. Sometimes this kills people. Sometimes this happens before that person has been able to reproduce. Wouldn't this cause selection for people who at the very least don't have bursting appendixes (appendices just sounds wrong to my inner narrator in this context), but also for people who have smaller ones. Over time this pressure would decrease but shouldn't it theoretically over many many generations result in smaller and smaller, eventually disappearing, appendixes?
Whether a thing can be selected-out depends on the shape of the fitness landscape in the environment.
For example, appendix-bursts are clearly rare enough and treatable-enough that they cannot be selected-out in modern humans. (But almost nothing can if almost everyone is able to reproduce, and any selection effects will be driven by the number of children which is largely cultural.)
If a thing hasn't been selected out, you can roughly conclude either that:
1. The selection pressure to do so isn't strong. Either few appendix bursts occur in an ancestral env, or they don't disrupt reproduction bc they happen later in life, or are treatable, or other causes of death kick in before the appendix matters.
2. Or, if the selection pressure is strong, there is "nowhere to go" in gene-space that improves this aspect of fitness, within the search-radius. (Which is really equivalent to 1: the selection pressure isn't strong enough to search widely enough)
3. Or there is a stronger selection pressure for it, even if you can't figure out what it is, like the "backup gut bacteria" thing for the appendix. (Which is actually equivalent to 1/2 also: the selection pressure isn't strong enough to find a way to separate the upside from the downside)
We used to think tonsils are optional as well, and there seem to have been some studies that find a link between tonsillectomy & Crohn's, Hodgkin's or even breast cancer (from wikipedia).
There surely must be vestigial parts in our organisms, like the one in the article, but more often than not we have no fucking clue how they interconnect with the whole and what their function is.
Appendix is being appreciated these days as a reservoir of good gut bacteria. So there’s actually probably some pressure to keep it around. Appendicitis is a thing but of course not everyone suffers it. Maybe in the primitive world you were more likely to see your skull meet a rock before that happened in significant numbers of people in the population to the point it affected offspring counts.
I would think so. Who says that's not happening now? It seems reasonable that evolutionary pressure can be strong enough to have a significant impact in 1-2 generations (for example due to the introduction of a new environmental threat) or weak enough to take thousands of generations.
Agreed. There is, or at least were, some parts of the body that were only recently discovered and not just known about and assumed to be inactive. It was only in 2015 that lymphatic vessels were discovered in the central nervous system:
Man, does THAT sum up the current political climate in America.
There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, "I don't see the use of this; let us clear it away." To which the more intelligent type of reformer will do well to answer: "If you don't see the use of it, I certainly won't let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it."[97]
The Chesterton fence argument is that you need to understand why the fence is there. If you do understand it, and still remove it, it doesn't say that's bad.
A lot of this comes from the assumption that our organs each have a single purpose, so if the obvious purpose is not relevant in humans then the organ is useless. But most organs serve multiple purposes.
There is no grand design in biology. If something ain’t broke, evolution ain’t going to fix it. Retina in mammals facing backwards that gives rise to blind spot is one example. The laryngeal nerve that goes all the way down aorta and back up the neck is another
Also, if something truly serves no purpose, evolution will allow it to go away.
The classic example is the enzyme needed to make vitamin C. In our primate ancestors that lived on a diet rich in vitamin C, there was no penalty to losing this enzyme. Mutations that destroyed its function were not selected against. As a result, we now can't make vitamin C; the remnants of the gene for the enzyme have been so damaged that there's no path back to the working version.
He mentions that even if you're a giraffe, you have nerves just as long running to the end of your spine, and from your spint to the bottoms of your feet, so the extra length of nerve isn't really a problem.
There is a pathway for every possible configuration. It doesn’t dictate whether a configuration is optimal. Maybe the laryngeal nerve isn’t that bad. But that doesn’t guarantee all anatomy and physiology optimal
Not exactly. Everything in our body needs energy to maintain itself. It has to provide some value for the energy it consumes, otherwise not having it becomes an evolutionary advantage meaning evolution will gravitate towards it.
What a_c is getting at is that evolution can become trapped in local optima. The backwards retina in mammals is suboptimal, but it's locally optimal - the path from where we are to a better design (like the one in squid) is too long for evolution to hill-climb up to.
Eh evolution will certainly try to fix things that ain't broke, indeed it will try to vary just about everything at some point or another. Bad cable management remains because no one survives the intermediate steps between functional configuration A and optimal configuration Z.
Tonsils are a good example of this. New studies are finding that they may be part of the immune system. Anecdotally, I had mine removed as a child due to frequent tonsilitis. As an adult, I suffer from a number of airborne allergies. Most likely a coincidence, but it does make me wonder!
Evolution works on a different timescale than what science divulgation headlines, and selected lineages to care about how to cross deadly valleys even though they might have appeared rarely. There's little room for baggage.
Yep, evolution leaves behind things that were once useful, but sometimes those traits could still have some kind of latent function that we just don’t have the tools to detect yet
My grandfather managed to persuade me when I was 4 that beer comes out of man's nipples. Unfortunately, at the time he was supposedly too old for it to happen. And my father was too young. So, I've never seen it in action
My personal experience with multiple doctors, some in primary care and others in hospitals, is that they often don't care and just want to get you out of the door.
Bring up some symptoms not immediately easily attributed to something? Sorry, those are "nonspecific symptoms" and they can't help you. Maybe see a specialist, maybe not. Figure it out.
Obviously this isn't all of them, but it is definitely a decent chunk.
Do you think "unlimited leave" policies end up acting a bit like insurance models? Some people take a lot, many take a little, so it evens out to less-than-if-we-had-a-set-number-of-days?
Just for playing any sport the accuracy to instruct 100s of muscles to work in a certain way is certainly above that 10bits,
Pointing out positions in a 10cm x 10cm x 10cm cubic volume seems to possible significantly faster than 1/s.
The slower examples listed in the table all have some externalities like a motor/object manipulation feedback loop overhead (speed cubing) and or redundacy and are not optimized for pure information density, so I have no idea why they settled on that average, and not the optimum?
Object Recognition and Reading are already at ~50 bits.
> Just for playing any sport the accuracy to instruct 100s of muscles to work in a certain way is certainly above that 10bits
But significant portions of that process are not done by the conscious brain, and some aren't done by the brain at all (reflex and peripheral nervous system). We don't consciously think about each of the 100 muscles we're switching on and off at rapid speed.
See: https://github.com/mozilla/bedrock/commit/d459addab846d8144b...
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