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.
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.
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.
https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
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.
I don't know what i'll do if i ever need an MRI, otherwise i'd probably just find it cozy..
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.
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).
* 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.
Today X-ray dosages are way less because they use
https://en.wikipedia.org/wiki/Digital_radiography
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
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.
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.
--
[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.)
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?
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.
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.
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!
It absolutely should not be just nipped out proactively.
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.
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)
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?
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.
I think. I'm not a doctor or anything.
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)
https://www.nih.gov/news-events/nih-research-matters/lymphat...
That article is about mice, but they were later found in humans, too.
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]
Did you care about Chesterton when the previous set of fence-smashers went around smashing (much older) fences?
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.
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.
There has been a revolution in the understanding how this organelle works in the last few years.
https://www.sciencedirect.com/science/article/pii/S089865682...