Human gene linked to bigger brains was born from seemingly useless DNA
science.org
science.org
Secondly the question is not well-posed enough to answer accurately. What is intelligence, in this case?
The cytoarchitecture of brain parcels/regions varies significantly. If you have a giant cerebellum you are not going to seem very smart to us, but you may have a very large brain. At the other end, people have lived normal (if perhaps internally simpler) lives with tiny fractions of a typical neocortex. [0]
0 : https://www.sciencealert.com/a-man-who-lives-without-90-of-h...
Human: 7.4 - 7.8
Dolphins: 5.3
Chimps: 2.2 - 2.5
Ravens: 2.49
Dog: 1.2
Cat: 1.0
Mouse: 0.5
Rat: 0.4
eg 0 Currently the best predictor for intelligence across all animals is [forebrain]neuron count.[[5]](https://en.m.wikipedia.org/wiki/Encephalization_quotient#cit...)
1 In a meta-analysis, Deaner et al. (2007) tested ABS, cortex size, cortex-to-brain ratio, EQ, and corrected relative brain size (cRBS) against global cognitive capacities. They have found that, after normalization, only ABS and neocortex size showed significant correlation to cognitive abilities.
2 The notion that encephalization quotient corresponds to intelligence has been disputed by Roth and Dicke (2012). They consider the absolute [number of cortical neurons] and [neural connections]as better correlates of cognitive ability.[[16]](https://en.m.wikipedia.org/wiki/Encephalization_quotient#cit...)
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=corr...
This is the most up-to-date meta-analysis on the topic:
https://royalsocietypublishing.org/doi/10.1098/rsos.211621
> Brain size and IQ associations yielded r = 0.24, with the strongest effects observed for more g-loaded tests and in healthy samples that generalize across participant sex and age bands.
let's run with that idea.
I have more muscle in my legs so I must be faster than a rabbit?
Various hypotheses on how a larger brain is actually used to control a larger body and thus doesn't translate into specific "brain power" usable for intelligent activities are unsound.
For example, a very weak correlation between GPA and job performance exists. In some disciplines, like law, the correlation is strong. In other fields, like extreme medicine, there is no correlation.
Twins are great for ruling out genetic factors. It may still be the case that neonatal nutrition drives both head size and adult IQ.
(And how much education did they have? The field includes people who have and haven't gone to medical school, I assume.)
Extreme medicine, which includes field, mountain, and battlefield medicine, is a specialization of general medicine. You can study it as a part of various programs. I studied it as a specialization in a general practitioner's MSc program in Central Europe. Depending on the region, it is probably possible to specialize in extreme medicine as a nurse or an EMT.
There was a wide range of GPAs in that program because success was measured by a narrow range of criteria that did not include things usually considered "academic aptitude" - mainly the ability to follow resuscitation algorithms in simulations precisely. Some of the things we were scored by automatically were time to ECG, time to defibrillation, correct callouts to the team, intubation depth and time, and chest compression depth and rate. And failing to execute a particular algorithm meant immediate failure. Every other imperfection immediately meant a reduced score, and scoring was entirely metric-based in simulators, not open to human interpretation.
Scoring just 45% of the possible grade on tests was considered excellent. You had to demonstrate very high competency to pass. Mediocre knowledge of algorithms or skills in resuscitation was unacceptable because that would severely worsen the outcomes of actual patients.
If you either cared about your GPA or were primarily motivated by your GPA at school or university, it was clear that this would be a very difficult specialization for you. It was more for people who excelled in algorithm following, composure under stress, and perseverance; and those who wanted a high skill ceiling.
There are a few factors and that post gives a nice overview.
See: the spatial packing problem in human brains
Bigger bird brains ~= smarter birds. Bigger dog brains ~= smarter dogs. But you can't directly compare dogs and birds in that way.
"Brains matter, bodies maybe not: the case for examining neuron numbers irrespective of body size" https://nyaspubs.onlinelibrary.wiley.com/doi/10.1111/j.1749-...
"No relative expansion of the number of prefrontal neurons in primate and human evolution" https://www.pnas.org/doi/full/10.1073/pnas.1610178113
"The human brain in numbers: A linearly scaled-up primate brain" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776484/
"The elephant brain in numbers" https://www.frontiersin.org/articles/10.3389/fnana.2014.0004...
Neural architectures are very similar between closely related species, and differ wildly between birds and whales.
The book Deep Thinkers: Inside the Minds of Whales, Dolphins, and Porpoises is quite good.
Not really, otherwise whales and elephants would be way smarter, than us.
Well, some people say, they are, but it does not show in our intelligence tests.
And birds brains evolved differently than those of mammals, so maybe they are more efficient with their relative small brain? Because yeah, they are definitely smarter than dogs, who have a bigger brain.
And this is not further explained in the book, but it likely sounds like technology. And when you want to have and use technology, you have to do more than just splashing around..
Well, when you consider that we react to global crisis like a pandemic with more confrontation, than cooperation (there was no real exchange of technology between west and east and patents and licencing were still more important, than producing enough vaccines) and to the climate crisis rather with more wars over whats left of the ressources, than to unite and solve the problems - no, we are not.
We are smart enough to see, what could be possible, but unable to overcome primitive power struggles.
And cherrypicking, well climate change is the current problem, affecting the whole earth, so a smart species by my definition would act globally and coordinated and not only talk about it. But sure, by comparison we still seem to be the smartest around.
How do you know that? I mentioned this in another comment, but dolphins and orcas have more folds in their brain than we do, and folding is associated with greater processing power and higher function. Additionally, the areas of their and whales' brains associated with emotional intelligence are much larger relative to the rest of their brain than the same areas in our brain are. Their brains are very, very interesting. For example, they keep one brain hemisphere active during sleep since they are conscious breathers, and they actually alternate which hemisphere is kept awake.
Whales, dolphins, and orcas are damn smart, and I think there's evidence enough that we cannot conclude that they aren't more intelligent than us. Although they lack technological development, this is due to their living environment and physiobiology and not due to their intelligence. Orcas in particular have achieved complete dominance of their environment, aside from human activity, and are geographically widespread with diverse cultures. There are many cases where orcas actually use humans as tools, even training humans to help them in hunts (and not the other way around).
Humans existed a long time before proper technology development, and those humans were just as intelligent as modern ones. The ability to create technology is not a requirement for higher intelligence.
Even then, orcas do use tools, what they have access to. Without technology, humans stand no chance against an orca, and that goes for any animal in the ocean, from blue whales to great white sharks.
We see dialects, to an extent, in orcas, but we do not see the human behaviors we might expect.
The problem, I think, is in the pure consideration of it as intelligence. This is a limited view.
Why? But nonetheless, they have. They pass on locations, routes, hunting techniques, etc. vocally and behaviorally down through generations.
You and some of the other comments bring up a lot of things that don’t really have much to do with intelligence. They really only have anything to do with a human-centric view of intelligence.
Isn’t it more intelligence to convey all the information that you need to with the highest efficiency?
We rate a poet who can convey tremendous meaning in few lines as superior to someone who is long winded and their writing is full of bullshit and tropes conveying nothing but using many words.
One person alone is without language and without advanced tools, no matter how big their brains. See feral children.
It is possible that cetaceans pushed long ago pushed past complex verbosity into communication via wisdom and are all enlightened beings. Maybe they communicate electrically. Maybe they are in a local maximum of telepathic connection. I hope so.
Is that actually true? In cases of feral or severely neglected children who lack any exposure to human language, isn't there an impediment that prevents them learning more complex language later in life that exceeds anything that could be attributed to reduced brain development due to nutrition?
World wide hasn't intelligence been increasing, and while part of that is due to better nutrition, another part is due to better childhood conditions to enable intelligence? Exposures to the technology of language, written language, and similar at a young age seem to lead to an increased capacity for intelligence later in life.
I’m not for sure what feral or neglected children has to do with this.
To address your later point, intelligence does not equal knowledge. Any increase in intelligence in a person’s life seems to be intralifetime and doesn’t spill over to further generations. Increasing intelligence through diet and behaviors and such are just mechanisms for exposing the underlying intelligence that’s already there.
This is just one of the many paths to the fundamental question that plagues this sort of topic, what is intelligence. Is intelligence the capacity for gaining knowledge or having actually gained knowledge? Or maybe not directly related to knowledge at all, though the previous question was more about the capacity to gain vs the gaining than it was about knowledge.
It is known that the capacity a single individual changes based on what they were exposed to (feral/neglected children being the extreme negative cases, I'm not as well read on extreme positive cases). But perhaps we aren't talking about an individua's capacity and instead we are talking some baseline genetic average capacity for a larger group that doesn't take into account environmental cases pushing it to either extreme? But in such a case have we not defined intelligence so that technology's impact is excluded a priori?
I do not know it. I am not an expert and had only limited, (but fascinating) contact with them.
But I would assume, if they would be "way smarter", than they could and would find ways of communicating with us. As far as I know, the research shows that they can communcicate towards each other quite well, but not towards us beyond very basic things.
But of course that reminds me of an old joke:
A donkey and a dog on a farm are talking to each other in the evening and the donkey complains that he has so much work to do, but would like to become a writer. The dog asks: why don't you tell the farmer? The donkey answers, are you crazy? If he finds out, I can read and write, I will also have to do his bookkeeping.
Meaning, maybe whales and co. could communicate with us, but choose not to. But if this would be the case, their reasoning would have to include some very astonishing things, as whales are still hunted - which they likely could almost completely stop by telling us exactly that.
That’s a human centric approach and a little strange, because how do we communicate with them? We can’t understand them or communicate with them any more than they can with us.
Old Tom was an orca off the Australian coast who, with his pod, trained humans on how to efficiently catch whales. Old Tom demanded the tongues of the whales, which was given to him by the whalers.
Where's this evidence? What exactly does "more intelligent" mean to you? Do you think a dolphin can learn to play e.g. Chess? I doubt you can teach them to play even tic-tac-toe.
https://pumpkinperson.com/2019/08/15/increasing-u-s-head-siz...
Last link has a formula to calculate cranial volume.
Animal intelligence is vastly underplayed. Ants seem to be a very intelligent creature but they're little more than part of nature to us. We're similarly adapted to our environment, and those animals are adapted to our patterns and mentation by virtue of millennia of close contact / purposeful genetic pushes (eg, dogs)
City birds like crows and pigeons have puzzles they can play with like getting food out of garbage bins and so on. City birds tend to be more intelligent than countryside birds, even within the same species.
I always felt like cats are actually smarter than dogs in a lot of ways. Dogs have a lot of their brain power dedicated to manipulating and communicating with humans, as well as trainability. But untrained dogs just seem kinda stupid and helpless to me whereas cats can learn to be almost completely independent with next to no training. Dogs are evolved from pack animals of course which explains a lot of this.
I do love dogs though, just to be clear.
As so, larger animals have bigger bodies, and hence typically have bigger brains in order to handle/control their larger bodies.
They clearly have a different 'instructions per cycle' ratio from mammal brains.
If society collapsed I think it would be more beneficial to be ADHD than not.
They persist because not enough time has passed to mutate them out.
Different architectures, like in tech, have different specs.
More is not always better, as a bigger brain is costly, and the price is only sometimes justified - as with buying more GPUs.
the interaction between DNA and polymerase class nucleo-polymers result in assembly of sequence conservative polymers.
for the most part this is RNAclass material, but includes DNA during replication and error correction events
https://www.quantamagazine.org/how-computationally-complex-i...
https://www.sciencedirect.com/science/article/pii/S089662732...
"Unfortunately, it’s currently impossible for neuroscientists to record the full input-output function of a real neuron, so there’s likely more going on that the model of a biological neuron isn’t capturing. In other words, real neurons might be even more complex."
these are histeretic, programable, and dynamic.
the neuronal body state, the electro-osmotic environment, the past history of state are primary effectors of structure,and function resultant in the logic.
I didn’t expect this topic to be so controversial to be honest. I’m not surprised though.
For information on the modifying DNA expression in neurons that's under epigenetics and not as well studied.
Don't let my negative attitude keep you from doing research- I just think that epigenetics has been a bit overblown as a functional mechanism, or its just too hard to prove anything useful with experiments. Personally, if I was working on this I'd focus much more on neural differentiation during neurogenesis, rather than self-modification during "runtime".
I’m focusing on the epigenetic aspect of neurons due the possibility of the ME/CFS/LongCovid family of conditions being due to silencing of certain genes. The brain is closely linked with the immune system and I think the so while these present as immune conditions I believe it starts out more as a neural condition, maybe microglia. In addition it makes sense to focus on this area more as I can’t consciously restructure the neurons in my brain but I can introduce peptides that change gene expressions.
[1] https://en.wikipedia.org/wiki/High-performance_liquid_chroma...
isolation,and analysis are two different activities, many instruments are capable of both modalities, depending on technique.
the problem is selecting a procedure that will not induce confounding artefacts of chemical, or physical interaction w the subject molecular entity.
Obviously, because it isn't junk; it is of value to the organism. Even if it's not of any use right now, even if it's completely biologically inactive at present. Because it is still extremely high entropy information. They're remnants of solutions other living systems once used, at some point, to solve the problem of staying alive.
If I were going to try and exploit genetic mutation to produce novel solutions to biological problems, I would start from an existing genome. In fact, I'd start with as much data, from as many organisms, as I could get my hands on and store. Perhaps we carry junk DNA because mutations in existing coded sequences, even mutated, currently useless ones, are far more likely to be functional, and so potentially a useful adaptation, than literal randomness. It's life's portfolio of solutions, badly photocopied little snippets accumulated over the years, and we all carry it around for future generations that might live in an environment where it's useful.
The fact that we can tap junk at some future point is probbly just an accidental side-effect... though there is another theory that claims having lots of junk provides some protection against environmentally-induced damage because most of the time it is a junk section that gets damaged. Hows that for the next error protection algorithm: pad the message with mostly zeros so occasional bit corruption doesn't matter. Take that Shannon!
If you want a specific example of this mechanism working: primate 3-color vision. In our two color blue-yellow seeing ancestors the yellow pigment sequence got duplicated, then eventually slightly mutated. That's why the red and green receptors overlap so much yet blue is standing way off by itself. It is high likely this started as a useless duplication and was carried around for a long time before one of the duplicates got mutated.
Can maladaptive mutations really be caused by copying DNA that's not used much (as far as we can tell, like the DNA for endogenous retroviruses in our genome)?
In other cases, there are just lots and lots of duplicates of the same genes over and over. Other parts appear to be forges of gene creation- either through gene duplication and divergent evolution, or through some other mysterious mechanism we don't know yet.
Certainly, we've had parts that looked like they were nothing at all and ended up being very important, and other parts that looked like they were incredibly important, but were really just the side effect of some effective parasite.
It's sort of not even an interesting debate any more, as most of the initial positions everybody held were changed when we interrogated more, and better data.
I’m thinking by analogy of executable programs that have runs of zeros. The zeros don’t necessarily do anything, but remove them and everything else is out of alignment.
We already know that enhancers "work at a distance" and it's not clear what "distance" exactly means, and it gets into complicated 3D structure of the genome inside a cell; see https://en.wikipedia.org/wiki/Enhancer_(genetics)
Personally I think that the best way to think about the genome is to unlearn most of the preconceptions you learned in genetics and instead think about it in terms of biophysics and development and machine learning: you'll never realyl be able to understand the true function of every little bit, but you cvan probably create an approximate model that explains the vast majority of biology with relatively few variables, and some deep models that contain all the necessary statistics to model these systems accurately.
ALU elements: Know the SINEs [short interspersed elements]
Alu elements are primate-specific repeats and comprise 11% of the human genome. They have wide-ranging influences on gene expression. Their contribution to genome evolution, gene regulation and disease is reviewed.
https://genomebiology.biomedcentral.com/articles/10.1186/gb-...
[1] https://utorontopress.com/9781487508593/whats-in-your-genome...
- Is extremely difficult to remove, at a worthwhile scale, from the genome of any large & long-lived organism
- Can be thought of as a huge pile of tickets for the Extremely Favorable Random Mutation lottery
Science is fantastic to dig into areas it can already see, and terrible at seeing new areas from the greater unknown.
ISBN-13: 978-1442634992, ISBN-10: 1442634995
If the primary goal is survival based primarily on efficient use of energy. A lot of evolution is about organisms becoming more efficient by adapting to their environment. So then keeping unnecessary junk around is inefficient and we would expect orgasms that lose to would benefit and out breed the others.
and then we get IRL "Pinky and the Brain"
Considering how we've managed to use those bigger brains, that DNA still seems useless.
It would be interesting to use seemingly unused DNA to express genes. But I also wonder if these truly lack a function, or if we just don't know the function.
Imagine you're the proverbial alien tasked with introducing sentient life on Earth without arising much suspicion. Replacing useless DNA with de novo genes (of high correlation) would likely be your favorite approach.
Whereas I'm not even sure that a million of generations is sufficient to evolve new genes from scratch (i.e. not via duplication or fixing)
Wheteas
[1] Morphogenesis as a Model for Computation and Basal Cognition by Michael Levin https://www.youtube.com/watch?v=ZW73LgOM5Bw (Where is Anatomical Information Specified - from 7:30 onwards)
Therefore, there might not be any morphological secret in the DNA, junk or not: DNA encodes a recipe for the building tools to be used in the eventuality of development. Imagine I would extract the exact state of the transistors from my computer, a ridiculously long string of 0s and 1s. Which strings of 0s and 1s codify this very textbox, its background color, the position of the cursor, the cursor itself? The questions are simply at the wrong level of abstraction, even if of course the state of the textbox is certainly somewhere in that string, but if I wanted to alter state at this wrong level then I would have to move very carefully a lot of 0s and 1s, in a very particular manner, with almost no room for errors, in order to add a simple "a" character to this very textbox. Isn't it much more simple and much more interesting, in the waterfall of effects through the abstraction layers if not in action, to push the key "A" on the keyboard? The question then becomes what is and how do we press the keyboard to alter the morphospace location of a cell, a tissue, an organism. A possible answer researched by Mr. Levin's group is voltage-gated ion channels controlling bioelectrical gradients [2].
Of course, at the lowest level, we are all stardust, a collection of femtoevents between femtoparticles, but we simply do not have to operate at that level to understand and control biology: biology itself has done the work, for at least the past 4+ billions of years of evolution, to increase the level of abstraction, from bonds between carbon and sulfur [3], to rotary motors to store and transfer energy [4], to organisms capable of running some kind of simulation of the world in which their reflected self becomes an agent in the world which sometimes knows they are an agent.
[1] Michael Levin | Cell Intelligence in Physiological and Morphological Spaces https://youtu.be/jLiHLDrOTW8?t=1201
[2] Exploring the Behavior of Bioelectric Circuits Using Evolution Heuristic Search, https://www.liebertpub.com/doi/epub/10.1089/bioe.2022.0033
[3] At the very beginning of life on Earth: the thiol-rich peptide (TRP) world hypothesis, https://pubmed.ncbi.nlm.nih.gov/29139533
[4] ATP synthase — a marvellous rotary engine of the cell, https://www.nature.com/articles/35089509
I understand your computer analogy, but I think it's misapplied because the opaque string of 01s requiring exquisite manipulation is exactly like what DNA was before we had modern genetic engineering, CRISPR, etc. And we walked the path your analogy suggests is ridiculous and impossible, to arrive with the contemporary genetic tools we now have.
I think "junk" is morphogenetics (and more), just in a different language that published science does not yet understand.
One other lesson to be learned from the planarian flatworms is that their DNA is a complete mess, yet they are able to fully regenerate without any issues, and are functionally immortal, they do not age [3].
DNA is certainly important and interesting and needs more research, my initial comment just pointed out that if DNA is a "CAD model", the computational layer, the basal cognition in cell/tissue/organ(ism), is even more enticing, and probably we don't even need to alter genes in order to shape morphology, giving another analogy, if a pocket calculator "knows" what 5 + 7 is, we probably don't need to build another pocket calculator just to compute 6 + 8.
[1] A Computational Approach to Explaining Bioelectrically Induced Persistent, Stochastic Changes of Axial Polarity in Planarian Regeneration, https://www.liebertpub.com/doi/10.1089/bioe.2021.0036
[2] Endogenous Bioelectric Networks & Regenerative Medicine, https://www.youtube.com/watch?v=HKWyB9qLP_s (Impossible Biological Objects, 2-headed flatworms at 52:30)
[3] Planarians as a model of aging to study the interaction between stem cells and senescent cells in vivo, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4696462/
But the relevant thing is, they control expression by binding to pieces of non-coding DNA, which can be considered "junk" by strict definitions. So most genes are prepended by a block of if-statements.
Gene expression is an area of active research.
is this research done by the same people that expect us to believe that the universe simply exploded into existence?
> In depressive states, the mind may be seen in the image of such an antler, in all its fantastic splendour pinning its bearer to the ground.