[HN Gopher] Scientists have traced human tail loss to a short se...
___________________________________________________________________
Scientists have traced human tail loss to a short sequence of
genetic code
Author : priyankanath
Score : 122 points
Date : 2024-03-24 05:18 UTC (17 hours ago)
(HTM) web link (www.cnn.com)
(TXT) w3m dump (www.cnn.com)
| Joel_Mckay wrote:
| Some do, but get corrective surgery as babies.
| K0balt wrote:
| They buried the lede:
|
| Even if the driving mutation identified in the study could be
| undone, "it still wouldn't bring back the tail."
|
| Oh well.
| Waterluvian wrote:
| So I'm guessing this is less like, "we found the flag that
| toggles tail production" and more "we found a chunk of code
| that belongs to tail production"?
|
| The first bit of the article sure makes it sound like this DNA
| is what does it all.
| icegreentea2 wrote:
| The scientists believed that the extra AluY element was
| functionally working to block out a part the TBXT gene
| (exon6). In their mouse model, they first directly snipped
| out exon6, and found that mice that were heterogeneous
| wildtype TBXT and exon6 removed TBXT developed a full
| spectrum of tail phenotypes from no tail to full length tail.
| At this point, the statement is "These results provide
| further evidence that the presence of TBXTDexon6 is
| sufficient to induce tail loss".
|
| They then tried to "more realistically" replicate the
| scenario. Instead of just snipping out exon6, they tried
| inserting in various elements into the mouse TBXT gene to
| emulate their model of how AluY is cutting out exon6. They
| attempted a few different methods which resulted in different
| models that would end up with different relative amounts of
| TBXT missing exon6 being produced. I'm having a hard time
| tracking all their conditions and lines at this point, but
| they seem to claim here that higher amounts of exon6 drop out
| correspond to shorter tails.
|
| They also found that they could not get any viable mice with
| exon6 snipped from both copies of TBXT.
|
| TBXT itself is a transcription factor, meaning that it
| controls the expression of other genes. There's probably a
| set of genes elsewhere that together make up the "tail-making
| machinery" that TBXT heavily interacts with. In this sense,
| TBXT 'might' be the most important single point lever, but at
| the same time not be fully in control of the underlying
| machine.
|
| What does seem persuasive is that idea that this mutation
| kicked off some rate of tail lose in our ancestors, which
| then lead to some sort of selection advantage. The advantage
| was then made more durable by accumulating additional
| mutations to lock in the phenotype. In addition, once the
| "tail making machinery" is inactive, we have no idea how
| those genes might have been repurposed. I think it's in this
| sense that the scientists say that we probably can't bring
| tails back just by "fixing TBXT".
| GordonS wrote:
| Just wanted to say thanks for this excellent summary!
| layer8 wrote:
| Probably the difference between necessary and sufficient.
| ummonk wrote:
| We found the flag that toggled tail production, but the tail
| production code is no longer in the codebase so turning on
| the flag again wouldn't do anything anymore.
| snovv_crash wrote:
| The code might still be there, but there are no tests for
| it, there have been millions of years of spaghetti code
| refactoring in between, and there aren't even any checksums
| on the storage to verify data integrity.
| Standards1 wrote:
| So close!
| 7thaccount wrote:
| The greatest thing on this thread is how disappointed we all
| are for some bizarre reason lol. It would be cool to get them
| back for better balance.
| sebastiennight wrote:
| A prehensile tail would do so much for my cooking skills...
| the possibilities are infinite.
|
| Wait - I finally found a use case for Neuralink that I can
| cheer for!
| underlipton wrote:
| You don't necessarily even need invasive surgery to
| control an additional limb:
| https://spectrum.ieee.org/human-augmentation
| datavirtue wrote:
| They aren't trying hard enough,then.
| FrustratedMonky wrote:
| A tail is grabbable.
|
| I'd think in primate fighting, a tail would be big negative. It
| could be grabbed.
|
| Can you imagine Chimp fights if they had tails that could be held
| on to and the owner dragged around.
| moffkalast wrote:
| The problem might be size, lots of smaller primates have tails
| which can be very useful as a fifth arm for holding onto
| branches. As you get larger, tree foraging becomes less viable
| and the tail less useful and it would need to be oversized to
| be able to function properly.
| whycome wrote:
| This seems like one of the times I can mention that dolphins
| and elephants have evolved prehensile penises. Sometimes
| nature finds a way.
| ndsipa_pomu wrote:
| And tapirs
| vbezhenar wrote:
| Most of animals don't use tails as a fifth arm. My cat seems
| to use it for extra balance. I think that humans could do
| that as well.
| OJFord wrote:
| Most animals are less dexterous than primates anyway.
| Humans talk about needing (or name products) a third
| arm/hand; small monkeys and lemurs and the like swing from
| them or use like you might imagine we would as an extra
| limb in climbing.
| nineteen999 wrote:
| Mine used to use it to tickle my nostrils and make me
| sneeze for its own amusement when standing or walking over
| my lap.
| amelius wrote:
| Replace tail by arm in your comment and see what is wrong about
| it.
| feisuzhu wrote:
| Arms are powerful but tails are not.
| freddie_mercury wrote:
| Crocodiles disagree.
| dotancohen wrote:
| Crocodiles are not primates.
| mkoubaa wrote:
| Seriously? Cost benefit. Arms have more benefit but not this
| cost.
| vbezhenar wrote:
| I don't follow. You can grab leg and drag owner around. How's
| tail different?
| marginalia_nu wrote:
| A leg has rigidity due to its endoskeleton, as well as strong
| muscles with good leverage, which when conditions are right
| gives it insane strength as it can act as a mechanical lever.
|
| Since a tail does not have a rigid endoskeleton, it can not
| act well as a lever. It's functionally a rope attached to
| your butt. Like even if you go full kangaroo mode and make
| the tail more muscular than the legs, making the tail rigid
| by flexing really hard, it basically turns into an
| inefficient leg with enormous mechanical disadvantages.
| icegreentea2 wrote:
| But the lack of ridigity also means that it's actually
| quite hard to control someone through it.
|
| If you grab someone's leg, especially near the foot/ankle,
| you are relying on the rigidity of the joints to be able to
| control their torso (and therefore their ability to fight
| back). The most disadvantageous position to be in is to
| have someone behind you, while they fully control your
| ankle/foot. Now you can't fully turn your body to face your
| opponent.
|
| For a sufficiently flexible tail, that would not be the
| case. Some could be behind you and control your tail near
| the tip, and you could still fully turn into your attacker
| with your torso.
|
| This isn't to say that a tail can't become a liability.
| lazide wrote:
| We have two legs, so grabbing one is a good way to get
| kicked in the face (or elsewhere).
|
| A flexible tail doesn't have that disadvantage to the
| grabber, especially if longer than a leg.
| kjkjadksj wrote:
| You can't land a kick when someone has your foot. Gravity
| exists, you will immediately fall onto your butt as soon
| as you lift the other leg.
| lazide wrote:
| On the ground is perfect for kicking them in the nuts,
| leg/torso strikes, sweeping their legs, or various
| control locks. It's a near ideal place to be to also get
| your opponent on the ground. You can also get a solid
| kick or sweep in, or throw them off balance on the way
| down too, if you're ready for it.
|
| You might find BJJ pretty interesting.
| [https://renzogracieacademy.com/about/what-is-brazilian-
| jiu-j...], [https://www.youtube.com/watch?v=u0edxg2fFmw]
|
| Judo teaches how to deal with it quite well too.
|
| The legs are the strongest part of a human, the arms
| don't compare at all. And fighting from the ground can be
| VERY effective if you know what you're doing. Or don't
| just curl up and wait to die.
|
| Ideally you'd be on your feet and able to move faster of
| course, and I wouldn't recommend against an opponent with
| a spear or other ranged weapon - but then they wouldn't
| be trying to grab my foot or leg anyway eh?
| LorenzoGood wrote:
| Although when striking is involved, leg locks loose much
| of their effectiveness.
| lazide wrote:
| It's always a race to get the critical hit or lock in.
|
| But unless the 'grabee' doesn't do anything, someone
| grabbing one foot from someone is likely using both hands
| (and most of their upper body) to attempt to control it -
| and there is a second foot/leg out there free to cause a
| lot of damage if they're willing.
|
| It's not a 'one and done'/'game over' scenario by any
| stretch of the imagination if the party is even a little
| motivated.
|
| Though I suspect most folks in this thread have no
| exposure to an actual fight beyond watching a video
| somewhere, so....
| LorenzoGood wrote:
| For me the main example of leg locks failing in MMA is
| Ilia Toporia's knockout of Ryan Hall in the UFC.
|
| Also, many powerful leg locks entries fail to succeed in
| MMA, due to overcommitment of limbs.
| lazide wrote:
| There are also a large number of banned moves in MMA.
| Nothing is perfect. Grabbing someones foot/leg isn't a
| one and done deal, either way, because we do actually
| have two and they're pretty powerful.
| datameta wrote:
| Coming from a stand-up striking Muay Thai perspective the
| only low risk way to grab a leg is intercepting a kick.
| You are then out of range of their upper body attacks and
| have total leverage physically and tactically. At that
| point unless the fighter whose leg is grabbed is
| extremely experienced in keeping a one foot balance by
| avoiding sweeps (ignoring the fact that one can bring the
| fight to the ground in MMA or BJJ etc - which imo is not
| preferable in a street fight) they're in a supremely
| disadvantaged position and at the will of the grabber. In
| a tournament, though, these situations usually resolve
| very quickly one way way or the other.
| icegreentea2 wrote:
| Right, but if we're seriously talking about the
| liabilities that having a tail has in a fight, then
| presumably most of the scenarios would involve attacking
| from behind. Remember also that this would be mostly
| quadraped animals too. Legs would have been strong, but
| likely still arboreally adapted, so a relatively strong
| upper body as well.
|
| In such a scenario, you'd probably attack from behind
| from a bit of an angle to force strikes from the other
| leg to be severely cross body.
|
| My original point was not that attacking the leg was
| easy, my point is that a flexible tail doesn't give you
| much leverage and control and may not be as much of a
| liability as you think, since if you could access the
| tail anyways, you probably also had their back.
| Macha wrote:
| Legs have a lot more muscle to allow the owner to resist,
| along with the downward weight of the body somewhat adding to
| stability?
| t-3 wrote:
| Hair is much worse in that regard, as the tail would be
| positioned too low to practically grab (it would asking for a
| knee to the face or punches to the back of the head or spine if
| you tried). I think the driver is more likely to be bipedality.
| A tail doesn't provide a lot of benefit for balance or rearside
| whisker utility when moving on two legs, and would interfere
| with sitting and lying postures. I think humans are probably
| too large for practical prehensile tails too.
| ohyes wrote:
| > I think humans are probably too large for practical
| prehensile tails too.
|
| There's only one way to find out! Who wants to join my
| 'prehensile tails for humans' (and other great apes with
| cash) startup?
|
| Capitalism, wow!
| thaumasiotes wrote:
| > I think the driver is more likely to be bipedality.
|
| Given that the tail was lost before the development of
| bipedality, how could this possibly be the case?
| didgetmaster wrote:
| The NFL would definitely have to come up with a rule about
| grabbing the tail of an opposing player.
| bilsbie wrote:
| If we did have rails do you think we would cover it up or keep it
| out like our hands?
| nutrie wrote:
| Not sure about rails, but I'd definitely mount an umbrella on
| my tail, just in case it rains.
| Razengan wrote:
| Imagine the fashion accessories!
|
| (and sexual kinks)
| DonHopkins wrote:
| My favorite "Scan Scene" from The Congress (Ari Folman's film
| based on Stanislaw Lem's novel "The Futurological Congress"), in
| which Harvey Keitel's character "Al" tells Robin Wright's
| character "Robin" the twisted tail of "Joey Fairytail"...
|
| https://www.youtube.com/watch?v=pPAl5GwvdY8
| tomtomistaken wrote:
| I love the book!
| DonHopkins wrote:
| "The Congress" is to "The Futurological Congress" is to
| Stanislaw Lem like "Blade Runner" is to "Do Androids Dream of
| Electric Sheep" is to Philip K Dick.
|
| Both great movies loosely based on both great but very
| different books by great authors, each with something unique
| and deep and important to say, that all stand on their own
| and are worth knowing.
| usrusr wrote:
| Wait until you've seen the Ijon Tichy miniseries. It's .. a
| different approach.
| 29athrowaway wrote:
| Monkeys have tails to swing and walk in trees.
| ndsipa_pomu wrote:
| Yet there's plenty of animals that have tails and don't spend
| time in trees, such as dogs, horses and cows.
| dboreham wrote:
| The tail seems like vestigial anatomy (originally useful in
| fish) that has three possible states in mammals: 1.
| Repurposed for a new function (tree swinging, signals) 2. Not
| much used but still in the repo (mice) 3. Garbage collected
| (apes).
| ndsipa_pomu wrote:
| I'm curious about the "garbage collected" theory as there
| doesn't seem like a lot of selection pressure to remove
| tails simply due to them not being useful and consuming
| energy to grow. The appendix is a far more likely candidate
| for garbage collection as it has no obvious function and
| can easily cause death if it bursts.
|
| I suspect that there's another reason that apes lost their
| tails - most likely related to walking on two feet.
|
| Edit: According to this study
| (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6417348/),
| the tailed chap had difficulty/pain when sitting and during
| other activites
| wizzwizz4 wrote:
| > _The appendix is a far more likely candidate for
| garbage collection as it has no obvious function_
|
| Preserving the gut microbiome through diarrhoea and
| vomiting.
| dTal wrote:
| Tails are extremely useful to mice, especially for balance
| and climbing:
| https://www.theguardian.com/lifeandstyle/2019/apr/30/why--
| mi...
|
| Be careful with assuming functionlessness, in general.
| Evolution does not like spending energy on sticky-out bits
| that are prone to injury, or good handles for predators to
| catch, unless they provide some serious advantage.
| nightfly wrote:
| Also used to distract and confuse (deer and rabbits)
| rikroots wrote:
| Kangaroos use their tails as a fifth leg -
| https://phys.org/news/2014-07-tale-kangaroo-tail.html
| Hackbraten wrote:
| Yet, according to TFA, apes had already lost their tail while
| they were still tree dwellers.
| blacksmith_tb wrote:
| Presumably as primates got bigger, tails were less useful
| (not strong enough to be prehensile appendages, and not as
| handy for balance if you climb methodically instead of
| carefree leaping).
| pfdietz wrote:
| It takes metabolic resources to grow a tail. If the benefit was
| less than the cost, mutations that prevented the tail from
| growing were selected for.
| ekaryotic wrote:
| And they're unhygenic. Sheep farmers for instance routinely cut
| the tails of their flock because it is difficult to shear and
| becomes a breeding ground for blowfly larvae. That said, i saw
| a movie called Shallow Hal(2001) which had a scene in which a
| man was shown to have a tail. Now it may have been cgi, but it
| made me think that there must be a minority of humans with that
| mutation.
| ginko wrote:
| Why does the article mainly focus on the great apes? All apes,
| including gibbons lost their tails.
| anamexis wrote:
| Presumably because humans are great apes.
| guerrilla wrote:
| I feel like people don't focus on gibbons enough in general.
| It's all great apes and monkeys all the time.
| Gibbon1 wrote:
| I agree with this 100 percent
| samatman wrote:
| The actual article in Nature points out that there have been
| independent tail-loss events in non-hominoid monkeys. Which
| makes it all the more frustrating that gibbons aren't mentioned
| anywhere. Given when they identify the mutation as having
| occurred, we can tentatively conclude that gibbons lack a tail
| for the same reason other apes do: 25 million years for the
| mutation, and 16.8 million years for the divergence of gibbons
| from the great apes.
| sschueller wrote:
| How long until humans have an actual "shelve" (indentation) on
| their pinkie at birth to rest their phone on?
| lbotos wrote:
| a long time? You probably need at least 7-9 generations to
| select "strong pinky shelf" as desirable and I'm not sure any
| culture is yet?
| coldtea wrote:
| > _You probably need at least 7-9 generations to select
| "strong pinky shelf" as desirable_
|
| It not only has to be convenient, but also to be sexually
| selected (partners with that seen as more attractive) or
| helping with survivability (partners with that live longer
| and get to reproduce more), which ain't really applicable
| anyway.
|
| Which is the reason we don't have traits for any other minor
| "convenience" attribute either, but instead for long standing
| evolutionary benefits.
| msm_ wrote:
| Even in case something helps with survivability, the
| benefit must be strong enough to be selected for. Even
| today people are dying because of appendicitis, can't
| imagine the death rate in the pre-modern era.
| jeromegv wrote:
| It's fascinating that most people don't get that about
| evolution. It needs to be a matter of life and death, if it
| doesn't, then it has no impact.
| ndsipa_pomu wrote:
| Surely it's more to do with the chances of raising viable
| offspring. A change that makes a person more desirable to
| the opposite sex is very likely to be selected for even
| if it makes the person more likely to die in their 50s.
| lazide wrote:
| 'It's complicated'.
|
| Blue eyes, for example.
| ndsipa_pomu wrote:
| Don't blue eyes support the "sexual selection" over "life
| or death" view of evolution though? Blue eyes don't
| provide any benefits to the owner other than possible
| sexual selection and surprisingly, they evolved before
| fair skin (which does provide a benefit for people in
| northern latitudes to produce enough vitamin D).
| coldtea wrote:
| > _Don 't blue eyes support the "sexual selection" over
| "life or death" view of evolution though?_
|
| Is it a choice? Evolution has both "life and death" and
| "sexual selection" aspects.
|
| And "sexual selection" itself is tied to "life and death"
| - it just concerns the life and death (or rather:
| existence or non-existence) of the offspring and not the
| person.
|
| So, in any case, it has to be big enough to affect
| whether the person gets an advantage in living more
| themselves, or gets an advantage for having children come
| to life.
| ndsipa_pomu wrote:
| Well yes, it's both.
|
| I was replying to jeromegv's earlier comment of:
|
| > It's fascinating that most people don't get that about
| evolution. It needs to be a matter of life and death, if
| it doesn't, then it has no impact.
| lazide wrote:
| I'd even generalize it to 'it's about passing on ones
| genes'.
|
| Death before one has had a chance to do so (or before any
| necessary utility towards one's offspring has passed) is
| evolutionarily 'bad'.
|
| Things that help reproduction and success for one's
| offspring? Evolutionarily 'good'.
|
| The tricky part is that a large portion of ANY human
| population is, near as I can tell, 'excess'/'hedging'
| population, and so will be 'doing poorly' in any given
| set of circumstances. Think of it as 'build time
| attribute randomization' when there is a random situation
| picked that people couldn't predict in advance.
|
| That means that population wide, when circumstances
| change, the portion that is doing poorly vs doing very
| well can shift appropriately so the overall population
| survives. It is quite expensive, but seems necessary for
| us to have survived so long overall with the sheer number
| of apocalypses we know of (from plagues to invading
| armies), and the undoubtably countless ones we have
| forgotten.
|
| This is true of any group or subgroup.
| ekaryotic wrote:
| blue eyes have better night vision. video related
|
| https://www.youtube.com/watch?v=FgAIWpVSAM8
| ndsipa_pomu wrote:
| Thanks, I did not know that.
|
| Lower chance of cataracts too.
| coldtea wrote:
| Given evolution? Thousands of years...
| raincole wrote:
| Never.
|
| Actually, considering how low the birth rates in developed
| countries are, humans would probably (very slowly) become less
| and less suitable for modern life.
| hawski wrote:
| I would hope that phones would not remain the last point in the
| evolution of a personal computing device in so far as to make
| it able to steer the evolution of humans.
| zare_st wrote:
| Never. Individuals with that kind of mutation have to be born
| per random chance, and then selected via sexual preference.
| ngvrnd wrote:
| There is no "why" -- it happened and was not selected against; it
| may have been adaptive and that is a kind of why, I guess. I
| think it would be better to be clear about this in science
| communication.
| Smaug123 wrote:
| The article itself is very clear about the sense of the word
| "why" intended here.
| JBiserkov wrote:
| Yes:
|
| > But while the new study explains the "how" of tail loss in
| humans and great apes, the "why" of it is still an open
| question.
|
| Title is still clickbait.
| Hackbraten wrote:
| The article itself states that this may be the case, or that it
| might have had some evolutionary advantage that we're just not
| aware of.
| o-o- wrote:
| There has to be more to it.
|
| If it's not selected against, it wouldn't spread at the cost of
| the tail gene.
|
| Somehow, somewhere along the genome line, non-tailers overtook
| tailers.
| BoiledCabbage wrote:
| > There is no "why"
|
| Of course there is a why. It happend and not only was it not
| selected against, presence of a tail was selected against.
| Meaning it was, or came along with a beneficial adaptation.
| That benefit is why it took over our gene pool and why we don't
| have tails now.
| tzs wrote:
| Probably good that we lost them. Judging by photos [1] of some of
| the rare cases of humans who were born with tails human tails
| wouldn't be aesthetically pleasing. Although perhaps human tails
| that are the result of something going awry might not be a good
| indicator of what human tails would be like if we had kept them.
|
| [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3263034/
| GordonS wrote:
| If we'd never lost tails, probably we wouldn't find then so
| "un-human". Also, presumably most people would have "normal"
| (as in, the same as most others) tails, rather than like the
| images in that article.
| jezzamon wrote:
| If we kept tails both the tails and our sense of what is
| attractive would be under evolutionary pressures so they
| probably would be normal to us!
| whythre wrote:
| I'm kinda glad I don't have to worry about sitting on my tail.
| Plus we get to avoid all the wacky tail based fetishes lol
|
| "He had a powerful, flexing tail, it's back and forth movement
| slow, deliberate..."
|
| "Her tail was slender and graceful, but she was unable to conceal
| the flush of arousal..."
| mock-possum wrote:
| I mean let's not pretend this fetish doesn't already exist and
| isn't already actively being catered to in written and visual
| erotica.
| reaperman wrote:
| Or various types of prosthetics. This fetish isn't being
| "avoided" at all!
| Loughla wrote:
| Exactly. Apparently OP didn't know Mew exists and has been
| fanfictioned in a million different sex acts (fanfucktion?).
| williamdclt wrote:
| Oh no, new aspects of human sexuality to explore, what a
| terrible thing
| huytersd wrote:
| Yes sex bad. Think of the women. I can't even begin to imagine
| being in this pathetic neutered headspace.
| _factor wrote:
| You're getting all the furries chiming in here.
| hsjsbeebue wrote:
| Chairs would have a tail hole. Just imagine having to sleep and
| roll over with arms in the way!
| underlipton wrote:
| My sweet, summer child~
|
| I can guarantee that each of those sentences is repeated
| verbatim somewhere on a certain website.
| immibis wrote:
| You can just Google them in quote marks, and they only appear
| here.
| tialaramex wrote:
| If we're doing germline edits, the _obvious_ thing to fix first
| is vitamin synthesis. There are a bunch of useful things other
| living things synthesise from first principles, and we don 't so
| we need to _eat_ something that has already synthesised the thing
| we wanted, and we can 't cook or preserve it in any way that
| destroys the material we needed or it won't work. That's what
| scurvy is, a tree or a lizard just makes its own vitamin C, but
| humans don't, so, if you're stuck on a ship eating preserved food
| for months your body runs out of vitamin C and you get very sick
| and eventually die. But synthesising vitamin C isn't hard per se,
| it's just that the synthesis instructions can be deleted and the
| humans are descended from an ancestor who had such a deletion, we
| can put it back.
|
| Once vitamin synthesis is back working, next up is amino acid
| synthesis. Amino acids are the constituent parts of proteins,
| your DNA is a bunch of instructions to fasten together a series
| of 22 different coded amino acids to make proteins. When you eat
| something, any proteins are broken back down into amino acids.
| Given some amino acids you can in principle make the others, but
| humans only make about half of them this way. As a result if your
| protein mix is wrong you are eating amino acids, and your body
| needs amino acids but some of them are _different_ amino acids -
| and instead of synthesising the ones needed from spares you don
| 't need using energy, which is abundant in most human societies,
| you just get sick and eventually (if you don't fix your diet)
| die. We should fix that.
| ruined wrote:
| and then, crispr cat ears
| klyrs wrote:
| Not the bombardier beetle's hydrogen peroxide cannon? I'll
| never understand furries.
| canadiantim wrote:
| Makes you wonder why we naturally selected for ancestors who
| didn't have the vitamin synthesis machinery. Clearly there must
| have been some evolutionary disadvantage associated with
| vitamin synthesis, or else as you say it's clear benefits
| should have conferred an evolutionary advantage and still be
| with us today.
| tsimionescu wrote:
| Not necessarily. If any early human diet that produced enough
| calories for them to live and procreate also happened to have
| plenty of vitamins, then synthesizing your own really didn't
| confer any evolutionary advantage.
|
| I'd also note I don't see any reason we'd want to synthesize
| our own vitamins now. It's virtually impossible to get a
| vitamin deficiency unless you try to eat a very restrictive
| diet for some other reason.
| smegger001 wrote:
| There was little selection selecting against the loss it when
| it was abundant in out ancestors diet at that particular time
| and place. so by the time it became an issue it was already
| missing from the gene pool and as it is easier for a mutaion
| to break a gene than it is to gain function so its unlikely
| to mutate back into the genome by chance.
| tgbugs wrote:
| Vitamin synthesis is one of the most pointless things to add
| because it is something that is lost in many lineages over
| evolutionary time. The reason is that as long as there are
| environmental sources of a molecule the pressure to retain the
| ability to synthesize that molecule natively is zero or even
| negative, because the synthesis pathways for some of those
| molecules are quite nasty. You could do it, but those people
| would probably have increased cancer rates due to running nasty
| biochemistry in their own cells and eventually their
| descendants would lose the ability the synthesize it again
| because vitamin C is naturally present in their environment
| unless they are e.g. British sailors stuck on a boat for months
| with a evolutionary strange diet.
| Ovah wrote:
| I'm surprised how the conversation shifted from genetics to
| unethical germline editing of things that barely have clinical
| relevance. The rates of scurvy in the 21th century are low and
| definitely don't warrant super invasive editing germline cells
| (!), changes which become hereditary. Adding vitamin synethesis
| is super complex: it's not just a single SNP change but would
| require a whole new enzyme system. It's a very fine line from
| opening up a big old can of eugenics worms. Adding extra tRNAs
| is sometimes done in microbiology but any health benefits are
| extremely questionable. I've never before seen germline editing
| be a proposed 'solution' to malnutrition.
| ordu wrote:
| If we are on this topic then we need to discuss a genetically
| modified gut microbiota. We do not need to edit genetically
| ourselves for some pityful vitamins. Microbiota could give us
| all we want. It could enable us to digest plastic, so we could
| eat food without removing its packaging. We could reduce
| severity of our waste problems by digesting plastic into
| relatively harmless poop.
| teddyh wrote:
| Maybe fix uricase production as well (eliminating gout).
| larodi wrote:
| time to bring it back then, alongside horn implants, and third
| tit.
| polishdude20 wrote:
| I'd I'd be drinking milk, it would be out of my nostrils right
| about now.
| vba616 wrote:
| How about a third eye?
|
| "The parietal eye is found in the tuatara, most lizards, frogs,
| salamanders, certain bony fish, sharks, and lampreys...It is
| absent in mammals, but was present in their closest extinct
| relatives, the therapsids"
|
| https://en.wikipedia.org/wiki/Parietal_eye
|
| You may wish to consult your pineal gland.
| agumonkey wrote:
| wings
| smoyer wrote:
| It's not all it's cracked up to be -
| https://craphound.com/someone/Cory_Doctorow_-
| _Someone_Comes_...
| makeitdouble wrote:
| Wings are so fascinating. Flying animals have their whole
| body, from their brain, digestive system, down to their
| bones internal structure and function [0] optimized for
| flight. That's where we see species giving up flight
| ability to get a stronger body, and I wonder what it would
| take for us to do the reverse to be able to use these wings
| in any way.
|
| [0] https://www.montananaturalist.org/blog-post/avian-
| adaptation...
| RobotToaster wrote:
| Would make sitting down rather uncomfortable.
| manarth wrote:
| @dang Editorialized title; original title for the CNN article is
| "Why don't humans have tails? Scientists find answers in an
| unlikely place"
| leke wrote:
| Makes me think of the episode of the Simpsons where Marge was
| modified to be some kind of human feline in the episode The
| Island of Dr. Hibbert
| speedylight wrote:
| Would be cool if we had tails, so I could wag it with my future
| dog!
| tempaccount420 wrote:
| But imagine if your tail was hairless :/
| cosmojg wrote:
| I imagine that it could still look cool if it were
| shaped/tapered in just the right way, maybe somewhere between
| that of a Sphynx cat and a lizard.
| bbarnett wrote:
| Meanwhile, 140k years ago, our 3rd civilization approached our
| current level of tech. Fashion designers, specifically a group
| lead by Argot the Great, decided the tail made pants difficult,
| and broke the lay of suit jackets.
|
| So they hired radicals to genetically engineer a retrovirus, to
| remove the tail. This worked, but due to unconsidered balance
| issues, all tail devoid children lost the capability for bipedal
| balance and therefore walking.
|
| Most of these children, during their formative years spent their
| time on all fours, and thud their hand dexterity was pitiful, and
| society crumbled when they came of age.
|
| It was another 46k years before a brain mutation emerged, re-
| enabling bipedal balance, but by that time all traces of the old
| civilization was lost, and thus, progress began anew.
| QuantumG wrote:
| Dehydrate!
| nelsondev wrote:
| If I had a tail, could I wave it with Kegels?
| ijijijjij wrote:
| now all we need is for the tailbone/coccyx to disappear.
| joshuamcginnis wrote:
| I believe this suggests that we could CRISPR an embryo to knock-
| out the offending Alu element in the TBXT gene and the child will
| develop a tail.
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