Did An Ancient Pathogen Reshape Our Cells?

[@matman7691]

It is quite insane to me to think about how something so simple (yet still so complex) as a molecule/protein is the only adaptation a pathogen needs to wreak so much havoc on animal life.

[@tsopmocful1958]

It was probably disadvantagous to the pathogen too, because it would have been much better for it if the host continued to survive well and reproduce after infection.

[@cosmoray9750]

mRNA

[@marisanya]

Think about what level of death is needed for a pathogen to create a lineage that successfully out-competed otherwise identical relatives because the relatives died so thoroughly that only the mutation survived? Pathogens move fast, they aren't like the multi-generational evolutionary pressures that make most of evolution move. It must have been incredibly devastating

[@tinfoilhomer909]

Well, the only wild horses who breed right now are the ones who are immune to PZP. I can't imagine what kind of mess scientists will see when they study wild horse endocrine systems a thousand years from now.

[@cadenrolland5250]

Over many generations so that it didn't come back. It didn't have to kill but likely did. It could have caused sterility.

[@WillArtie]

I know this may be silly/long shot but could such a possible mass dying be preserved somehow in the fossil record? or just too long ago....

[@Illuminanted]

I feel like it would've left evidence of a mass dying. Maybe there was one?

[@Findecommie]

@@WillArtie unlikely, primates at this point were arboreal and it would be another ~20 million years before homonids would bury their dead so there aren't a lot of fossils to begin with, and then you'd need either a lot of fossils all together or enough identifiably not-killed-by-injury-or-age fossils of the same age to suggest a plague

[@therealmariguana3097]

Could you guys do a video about menopause? Apparently the only animals that have it are a few types of whales and humans, hearing some theories as to why would be really cool.

[@mizzshortie907]

Whales have menopause? Wonder what the symptoms are?

[@ryanvess6162]

It's a mammal trait, dealing with longevity of life. Not a huge mystery there

[@paulteusner]

Yeah this would be great!

[@DonnaBarrHerself]

@@ryanvess6162 🙄

[@lancewedor5306]

@@ryanvess6162 ok. but limited to us and whales seems surprising. No others? I am curious enough to ponder this apparent fact.

[@OrdonWolf]

Girl-Boss: ❌ Alpha-Gal: ✔ btw has the loss of this molecule affected the frequency of rheumatic diseases? I imagine it would, hearing what it was used for.

[@ThisIsKassia]

I was also wondering about the effect on autoimmune diseases

[@MossyMozart]

@OrdonWolf - Rheumatic Fever is an autoimmune disease stimulated by a strep infection. (Rarely sickens Westerners anymore with such highly developed medical systems, but is still common in countries without them.)

[@alexcrazy1492]

Eons is on of the best informative KZbin channels ever

[@S0ulSUrviv0R713]

This & SciShow 🤩😍🥳

[@jordanengland8163]

Oh I don't know. That PBS space-time is some pretty good stuff.

[@KingNik1994]

absolutely

[@AnalyticalReckoner]

There are full lectures on youtube. This is pop science.

[@klulu-kun]

@@AnalyticalReckoner Not everyone has the time for that. Most people prefer digestible videos for daily facts on subjects they find fascinating. Plus the animations and art panels are more appealing than talk lectures. At least we know people watch it for the real science. That's all that matters.

[@GaryJohnWalker1]

So maybe with fewer offspring due to the loss of alpha gal, catahrrine (sp??) primates have had to invest more in each individual child? A push for that might eventually benefit intelligence. Rather than the other way round - as primates got brighter they then cut down litter sizes to one or two due to more input (attention/nurturing) .

[@infinitemonkey917]

Other species like elephants and rhinos have few offspring and invest much time in them.

[@silmarian]

At first I was wondering if this had anything to do with menopause. Alas, a quick google says we're the only primates that go through it. The other 4 mammals who do are all cetaceans.

[@lewismooney3941]

As well as longer lifespan!

[@jamespearsoniii914]

@@infinitemonkey917 reasonable to point out that size has a very direct influence on reproductive numbers

[@lewismooney3941]

@@infinitemonkey917 I get what you’re saying but that’s apples and oranges! It’s about the primates.

[@Hfil66]

If we assume that this change happened because of an encounter with a single pathogen over a relatively short period of time is that we would have expected to see a massive reduction in primate population at that time, and that should show up as a reduction in genetic diversity that can be traced to that time period. I would expect that this is a signature we should be able to search for to confirm or refute such a theory.

[@shelbylynn9]

I had that thought too. What about the corresponding genetic bottleneck?

[@Duodecimal12]

The mutation could have occurred long before the disease outbreak, but not so long that immune systems had further diverged, so they were all cross-communicating it still.

[@bbirda1287]

Does it necessarily have to be over a short period of time, or can the effects just be spread out long term and the disease so deadly that there was no other way to adapt?

[@Ranstone]

Not readily possible. In order to see a loss of genetic diversity, you'd need to observe the diversity before the event. We also can't reverse engineer it, because we already know all of the non Alpha Gal primates came from the same pool. Maybe we could compare the primates who were not affected with he ones that were... That would be the only possibility.

[@Argentvs]

I don't think it had to happen quickly, could be for millions of years. Imagine the primates population in EurAfrAsia being recurrently hit by pest waves, just like human societies has been for millennia. It does not cause a mass extinction of species, it just reduces population time to time. Species bounce back, thrive and then get hit again, with each hit the mutation carrying individuals have more breeding opportunities, increasing their population weight to a point it wash away the ones without the mutation. Pathogens that have a catastrophic death rate fail and go extinct as they consume their host population faster than replacement level. The pathogens objective is survival and reproduction, not killing. Those pathogens that do not cause so much harm nor dead become successful and out compete lethal ones. They can even displace or antagonize them.

[@Brieperalta]

Eons makes my days better.

[@Brieperalta]

Where are you? 🤔🌏🌍🌌👨‍🚀🧑‍🚀🛸👽😊

[@vodostar9134]

Oh, mammals have alpha-gal. So that's why alpha-gal allergy creates an allergy to red meat and dairy - products of mammals - but not chicken or fish. Good to know.

[@paulteusner]

Yeah, I'm sure we primates were vegetarian when we first developed this immunity, so the subsequent allergy to meat wouldn't have made an impact on the evolution.

[@infinitemonkey917]

Either that or it's just in your head / psychosomatic like the majority of gluten allergies.

[@skybluskyblueify]

@@infinitemonkey917 A lone-star tick cant wait to get ahold of you. "Acquired red meat allergy is an allergy to certain types of meat caused by the bite of a lone star tick. The allergy involves a carbohydrate known as Galactose-alpha-1,3-galactose (also known as Alpha- gal). This carbohydrate is found in mammalian meat (i.e., red meat) products such as beef, pork, venison, and lamb."

[@RyanTosh]

Or humans. Do with that what you will.

[@Dragrath1]

@@paulteusner Probably not purely vegetarian as their likely would have been an insect and other arthropod component to their diets as that is common source of food among primates and other animals today.

[@skiveman]

Videos like this give me hope that I'm not killing all my brain cells by watching YT.

[@bbirda1287]

Unfortunately, it might affect your attention span, I have noticed that I start channel switching on TV after 20 minutes or so.

[@ricecritter2727]

Interesting they didn't address the mammal meat allergy that people get from ticks involving alpha gal. I have several friends who have developed that. Becoming more common in Tennessee. Also Blakes laugh at the end is like, so adorable😻

[@catc8927]

Yeah, I was wondering when the Lone Star Tick thing would come up, and it never did.

[@razorransom1795]

@@catc8927 yup, indeed, the lone star tick which is spreading all over the usa lately because of their booming population and warmer weather. But, yeah, that is fastinating that the alfagal alleregy gets hyper activated, thus the red meat allergy

[@teratigerstudio4569]

I was waiting for this too since I have AGS 🥲

[@matthew6427]

My wife picked it up in Tennessee a few years ago too. It's amazing how many people still don't know anything about it.

[@samwill7259]

Between the existence of depressive or anxiety disorders, our upright stance slowly but inevitably destroying our lower backs, and now this. The Human body seems worryingly willing to attack itself at the slightest opportunity.

[@huldu]

It's quite interesting why these issues have become so highlighted in the last 20-30 years, especially the last 10 or so. Before that nobody cared or plain ignored the issues. Or it could be a byproduct of our modern society. Internet, instant access to things and all that. I'm a little concerned about kids today because all of this is just "normal" to them and you see the problems popping up all over the world. Then we have the old fashioned wanting to belong to something bigger than themselves at any cost. Internet again causes huge issues with children and teenagers. In time maybe our brain will adapt but evolution takes time so I don't see that happening overnight. We'll have to see what happens in the coming hundreds of years but it just doesn't look very bright for the planet or us as a species.

[@noticing33]

@@huldu in the mean time, billions will suffer ahahahahahahah

[@DaveTexas]

I’ve always known I was a mutant! Unfortunately, my main mutant power seems to be having an immune system that robustly attacks my own body. I’d rather have the ability to teleport or to shoot lasers out of my eyes, but mutants don’t seem have have the ability to choose their mutant powers...

[@spindash64]

I got the ability to drink milk, so that’s cool

[@PhilMasters]

@@spindash64 I got lactose tolerance - and also grey-blue eyes, which does actually seem to increase reproductive opportunities for some males of the species, so don’t knock it.

[@Jarmezrocks]

Me too

[@mrmakb.1368]

🤣🤣🤣🤣

[@MonicaGunderson]

Likewise. Ankylosing Spondylitis and have the HLA-B27 gene. I like to say we are Star Lords! 💙

[@NeilGirdhar]

Great episode! Interestic topic, nice animations, clear and pithy narration. More episodes like this please!

[@MrBenwaan]

Would a lack of alpha gal have allowed us to diversify our gut bacterias, letting us eat a more varied diet during hard times?

[@88smileandnod]

Ooh, I hadn't considered that. Wonder what other effect came from such a tiny protein change ?

[@Alice_Walker]

Thanks

[@ryanfitzalan8634]

if it did cause our ancestors in the catarrhines to have a shorter reproductive time span, than it may have also caused the selective pressure for more intensive socialization and group dynamics, which would push for altruistic behavior to guarantee survival of as many individuals as possible in order to increase population sizes. the chain reaction is ultimately responsible for everything that made humans what we are today. So the question as to the probability of hyper intelligent life in the galaxy or fermi's paradox, could actually be that something as minute as the probability for a group of animals to survive pathogen evolution in just the exact right way is the real barrier, which may be extremely difficult since it never happened before us or since.

[@arcies9286]

Well it's easy to say it's something simple as that, but that's still a gross oversimplification based slmost entirely on speculation, even if it's the way things went down. Occam's razor states the simplest theroies are likely more correct. One could easily argue any factor made us into what we are, some have caimed it was the development of language or adding Psliocybin mushrooms to our diet. We'll never honestly know.

[@jeremymullens7167]

My theory for intelligence is tide to flowering and fruiting plants. Primates that eat fruits have larger brains. Getting more energy can make you smarter or physically stronger. Smarter only happens if there’s pressure for intelligence. The secret to evolution is in general, evolution tries everything. It made physically bigger and smarter offspring and the smarter ones did better. You can look at the fossil and archeological record and see that human evolution radiated every time a new energy source was found. Fire lead to bigger stronger species and smarter species. Tool use was the engine that really ramped things up, more intelligence lead to better tools. Which leads to more access to food. Which leads to more intelligence (also bigger individuals but intelligence wins). The situation starts to but a higher and higher bottom for the lowest intelligence possible. Our tool use is shaping us now. Even more intelligence is required to function in society not just do well.

[@doigt6590]

@Purple Emerald we can't even say that, although I do believe we're first, because the universe is so large that it is entirely possible there's another which has reached our point of civilization in the non observable parts of the universe.

[@jasonreed7522]

@@doigt6590 also the further away an object is the farther back in time you are looking, this is both incredibly useful, and very limiting. (We can check out the ancient universe, but finding contemporary equals is much harder) Basically if we assume a civilization is equal in tech to us, if they are over 100 light years away it then their radio transmissions probably haven't reached us yet. On the other hand if a civilization is far away and we detect their radio waves then they could be hundreds of years more advanced than us. As far as what the "great filter" really is, why not accept multiple filters. Maybe just getting a single celled organism is very hard, and then a tiny fraction become multicellular, and another timy fraction become tool users, or intelligent. And once intelligent you have to survive yourself (look at the insane number of wars in our own history, and all the nukes we made, and used). And this says nothing of all the asteroids, gama ray bursts, and other planet sterilizing events that have to be dodged on pure luck. (And we have to decide what is scarier, being the first and alone, or not being alone)

[@nsl-u-boot8464]

Wow... Thank you for that thought!

[@jimminniehan2548]

He is the best presenter I’ve seen on there. Thank you well done.

[@Alexander_Evans]

I learned a lot from PBS growing up, and they just keep serving me up knowledge into adulthood.

[@UnknownName5050]

I’m sure you’re properly brainwashed as intended.

[@johnfalk6139]

Before they sold out to the government or are you talking about now.your smarter than that man give yourself more credit and see through the deception of why they're showing this

[@Sarafan92]

Absolutely fascinating. It's amazing how we can weave these stories from DNA. Science is so cool.

[@richardnzekwue1043]

Vineet. You are right. Scientists can do a lot with DNA. Code computers, create nanobots, create CRISPER, and weave the genomic map of all life on earth. It's a wonder how this self multiplication machine formed from non living matter.

[@vedantsridhar8378]

Science is so cool. Yet it can also be hot. At least the science I'm studying now is hot, because I'm studying thermodynamics and nuclear physics

[@CosmicShieldMaiden]

@@vedantsridhar8378 talk nerdy to me

[@axolotlonzo2683]

@Bear Greendale is your name really bear

[@-aid4084]

@Bear Greendale what'r you hinting?

[@NosmoKing001]

This just blows my mind. The advances in our understanding of genetics is giving us the most interesting information.

[@Petrov3434]

Thanks!

[@JustMeJH]

Great video! The animations were beautiful.

[@ippbrescia]

Your videos are always fascinating, I am also learning a lot by watching them. Thank you so much for creating them and publishing! Plus I love your puns

[@dawnhughes9942]

This resonates with my DNA! I have the 2D6 deletion that makes me unable to process opiates. I have a built in defense against the horrible drug addictions destroying many lives today.

[@MossyMozart]

@Dawn Hughes - I am unable to produce antibodies to some diseases even after being vaccinated. Another immune deficiency. (I produce antibodies to C-19 following vaccination, thank goodness, but no T-cell response.)

[@kalkinara]

What kind of tests do you need to find that out .?. I don't know more about this topic ..Can you elaborate please?? I mean it is amazing how you came to knew about this amazing ability ..

[@maxim_ml]

@@kalkinara same

[@salp4082]

idk why but 2:22-2:40 was quite beautiful editing there, nice imagery esp. with the music

[@tj3056]

Can you guys please do a video about dingoes? I've heard there is a debate about whether or not they were domesticated by the Aboriginal and Torres Strait Islander peoples of Australia. I'd also love to see episodes on the Canowindra fish fossils, Mungo lady and Mungo man, the Naracoorte caves and the Riversleigh World Heritage Site. There are some truly amazing fossil sites in Australia

[@aisforinterval]

I wonder how this affects autoimmune diseases... Are they more common in the platterhine apes than other mammals? 🤔

[@jondw]

possibly holdouts from survivors by chance of this hypothetical disease in some cases?

[@sciencefliestothemoon2305]

Hard to say, most animals having a autoimmune disease would die rather quickly.

[@MossyMozart]

@@sciencefliestothemoon2305 - Depends on the disease. I was in my 60s (from age 6) before rheumatic heart disease required that I get a pacemaker.

[@sciencefliestothemoon2305]

@@MossyMozart that is luckily for you a slow progression.

[@aplaceinthestars3207]

Simplistically speaking... does this mean donor organs from c-primates to other mammals is a thing? I'm not into body horror or veterinary science, so I've never thought of this at all.

[@CricketsBay]

It's not. Pigs are more compatible for human organ donations than other Cattharine Primates are.

[@halagavi]

Ethically, I'm not so sure...

[@selinaykaynak5179]

Apes together strong

[@Carewolf]

They have just gene edited pigs to be more like humans and used those mutant pig organs.

[@nikenpermanasari2224]

Yes and some plotting by top scientist trying to legalize and familiarize animals transplant to human being. Not, I will never buy it till angel of death take my soul. However I can't say for most people. From lot of comments, most people are brainwashed to accept it as if as it was just a norm something.

[@nickrider5220]

This helps to answer why we humans are really very recent, I'd often wondered why that was. Our branch was devastated and took a long time to recover and diversify. I love learning new things - thanks PBS

[@jamestang1227]

I don't see how they're related. Catarhine primates presumably bounced back to produced Old World Monkeys and apes, which is a diverse group. We have multiple species of ape roaming the old world before the human line split off from the chimp line.

[@VitaeLibra]

@@jamestang1227 Yeah as you said this exact case wasn't related to humans in any way. Simply too long in between. But humans were at some point down to 10k~ surviving members which may have been due to a similar situation. Although more likely because we got bodied by anything with a pulse. Then we invented sharp sticks :)

[@helloiamchuck]

So basically, we're all the descendants of the mutant survivors of an apocalyptically deadly plague. Evolution sounds a lot like the plot of B-grade sci fi movie sometimes.

[@dannybrown5744]

You say b grade...

[@Fanrak-2700]

At this point i believe that the universe trys to get rid of Life by default.

[@notdolandark]

@@Fanrak-2700 Well uh duhh, life defies entropy.

[@spoodlenoodle]

Everytime I get a notification you guys posted I feel so happy, thank you!

[@christbw]

Love this, please do more biochemical and genetic evolution stories!

[@Christopherkostro]

That's awesome that someone from my favorite area reviewed the script. I love your video's so that makes it extra special.

[@BytebroUK]

Hypothetically, if it became advantageous to switch that gene back on, would it be a big thing, or maybe unnoticed?

[@hexamex]

It could be difficult, as the mother would have alpha-gal antibodies so the infant with alphagal would be attacked.. but who knows?

[@mariamgarnes]

Apparently it impacts the way our immune system attacks pathogens so it probably would be noticeable

[@helenel4126]

@@hexamex, see the information about people allergic to alpha-gal; caused by having been bitten by a Lone Star tick, as I was. Believe me, you don't want to go there!

[@MackNcD]

Best episode of PBS eons in a loooong time

[@charleslord2433]

Truly fascinating! Great to see new episodes!

[@Xnaut314]

The presumed correlation of alpha-gal and delayed sexual maturity is an intriguing observation, but is not necessarily a cause-effect analogy. To prove that, you would need to see an opposite effect in prosimians and New World monkeys and have them consistently reaching reproductive age at a significantly earlier stage in their average lifespans compared to Old World monkeys and apes. Primates in general already have only one or a few offspring at a time compared to the large litters of mice, so that side effect in the lab might not simulate the scenario that it is being compared to.

[@Cruxador]

You're a bit off. The comparison you're describing would only show correlation, not causation. On the other hand, the study with the mice did show causation, in the mice. However, you're right that it doesn't necessarily mean that the same effect applied in real-world example and whatever mechanism existed in mice that caused it could be different or offset in the simian ancestors.

[@JohnDoe-qz1ql]

New world... OLD world??? Very european thinking of you.

[@salemsaberhagan]

@@Cruxador essentially the question is whether human & mouse reproductive systems are similar enough for alpha gal to affect both of us in the same ways

[@salemsaberhagan]

@@JohnDoe-qz1ql historically, geologically, biologically & evolutionarily speaking, it is a useful & practical distinction. Please take your outrage to a channel dealing with more contemporary, anthropocentric topics. And once you do, have the spine to use an actual identity or internet persona.

[@GiantEagle610]

Is Alpha-gal loss a possible reason why humans are plagued by autoimmune diseases such as SLE?

[@kelliepatrick519]

I've heard a hypothesis that many autoimmune disorders are from the interdiction of Neanderthal DNA into the Sapien gene pool.

[@MossyMozart]

I'm going to have to re-watch this one a time or two more.

[@thedinosaurfiles5352]

Could you do a video on spinosaurs and its realtives? It seems left out in paleontology.

[@alison4316]

Baryonyx 👍🏻👍🏻

[@KSWfarms]

They actually do have one already but it's kind of out of date now with the new research that's come out in the last few years.

[@aniksamiurrahman6365]

I thought it's just an episode about Mitochondria. But what I saw totally blew my mind!

[@seanmortazyt]

so well written and presented

[@highfive7689]

Here's episode idea for a future program. The evolution of human diving and holding breath underwater - what allows us to do so. You can even comment on such things as the aquatic ape hypothesis. I must complement you, ever since your first episode Eon has been a "VIRAL" sensation - Love you, EON. 😜

[@lh3540]

Idk, not my field; but people are forgetting that most wild ape populations only have 5,000 to 100,000 members. An evolutionary bottleneck of this kind in an early primate could have happened in the thousands, not the 8billion humans we're used to seeing.

[@helmivanwinden847]

Another interesting video about moleculer evolution. Please combine all these in one playlist, for easy access.

[@lexicalgap5191]

I wonder if one additional effect of losing alpha gal is increased prevalence/severity of auto immune conditions. It would be really interesting to see research on that.

[@michaelciarla3836]

I really appreciate these videos you guys put out! I love them, and can't wait for the next one. 👍👍

[@AZombieWizard]

Instead of asking "did one reshape our cells" I think a better question is how many times did it happen?

[@njlkerins]

Excellent episode, thank you!

[@paulteusner]

This video is so fascinating. So it means we're the descendants of the remains of a pandemic that almost wiped out our entire order. Were primates close to extinction in the 'old world' 30 millions years ago?

[@dannybrown5744]

Yes a huge bottle neck

[@notdolandark]

@@dannybrown5744 Dose that line up with the other bottleneck evidence of all out mitochondrial DNA being descended from a single primate, or is that an entirely different bottle neck?

[@burnte]

I absolutely adore this channel.

[@christopherbrand5360]

And alpha-gal is the key to tick-borne meat allergies! So cool :)

[@lb5368]

I learned about the existence of alpha-gal from Radiolab (WNYC) several years ago. I highly recommend listening to those, because they talk to people who live with activated apha-gal. Fascinating stories!!

[@Hi_Im_Akward]

I was wondering if you could do a video about other primate lineages and what archeological finds that have been found. I know the human lineage is interesting and diverse but I don't hear too much about early ancestors of chimps, gorillas ect.

[@olwolf]

Fascinating topic and theory. Thank you for sharing this with us! 🐺

[@HaikatrineKat]

Eons: Over a hundred and twenty-five million years ago... Me: 👍🏻

[@Catseye189]

I love how nature keeps things around. That gene is deactivated, but still there!

[@TheAquaticMandolin]

So in a sense it was almost like an AIDS situation where the body was fighting off an autoimmune like virus? And in this case it just played over many generations with no cure or treatment. So by sheer chance and presumably a catastrophic die off, the primates that didn't have it survived? This is a really cool episode. Hate that a lot of people or animals had to die off to make it happen, but it's a fascinating outcome of evolution, I love it! It just goes to show how humans and all animals in general have been in a never-ending arms race against the bacterial and viral world, time immemorial.

[@anubhavpal5782]

well who knows solving the aids, hiv and other auto immune diseases might involve something similar approach. Its just none of them have been so catastrophic or deadly as this one to force a change in our genome or make some genes inert

[@Samu2010lolcats]

It could have been that, or it could just bind to it. In which case it would have been more like a deadlier version of Covid. Pathogens that are both very deadly and very contagios tend to have a dramatic effect on a population in the span of just a couple generations.

[@dannybrown5744]

@@Samu2010lolcats could be a similar reason horses went extinct in America. A pathogen can take out whole species and more...all the mega fauna for instance.

[@Argentvs]

Fun fact, there is several people around the world inmune to HIV.

[@crowe6961]

@@Samu2010lolcats They also tend to burn themselves out quickly unless the population density is high or they have a truly obnoxious incubation period.

[@domquixote56]

Brilhant as usual! Congrats!

[@silversurfer8818]

A duplication event which had a more efficient promoter region replaced the old one? with a slightly different function?

[@MamaGypsyFelice]

Thank you very much for sharing this with everyone 😊

[@alarcon99]

Gosh I love science! And alpha-gal is why people that have been bitten by the line star tick will develop an allergy to eating meat products 🤯

[@noticing33]

The vegans are gona weaponise this.

[@somepath410]

Not just the video but comments too are awesomely cool theories. Just love reading through ❤

[@mrav8r]

Ok now my follow-up question is: how would this virus and all mammals get the exact same alpha-gal molecule on the surfaces of their cells? Is there a proto animal that is the common ancestor to the alpha-gal virus and primates?

[@twistedtachyon5877]

I'm just an internet ignoramus, but as I understand it, a virus I'd just a box of protein. Sticking a particular molecule (even a complicated one) onto that really doesn't seem especially difficult. Especially since viruses spend a lot of time smooshing their genes into cells' production centers. I'm sure in all the billions of copies of any given virus, snagging random little bits of host biology happens pretty regularly. The lucky virus that lands an indicator like alpha-gal gets a big competitive advantage, and away it goes...

[@mrav8r]

@@twistedtachyon5877 Hmm so isn’t this theory nothing more than virus-on-virus warfare? If we view humans as nothing more than DNA with personality, isn’t DNA just another box of protein as well? I am arguing from the perspective of an avid watcher of Star Trek. One episode from ST:TNG has a virus run rampant through the ship, devolving the crew down their respective evolutionary trees. In one case (spider-Barkley), it re-evolves him back up the spider branch. What I’m saying is , until I’m proven wrong, I’m proven right. 😀

[@bbirda1287]

A very early ancestor of mammals developed alpha-gal such that all mammals had it, whereas the theoretical virus was specific to Old World primates and so alpha-gal is only deleted in the Old World primates and their descendants.

[@brianmonks8657]

Viruses tend to bud through the membrane of the infected cell on the way out, getting coated with that membrane. If they infected a cell with alpha-gal on it's membrane, they will also have alpha-gal on their surface after exiting. That being said, I'm not a virologist, so I don't know if any viruses also contain the genes to make their own alpha-gal. Some bacteria can also produce alpha-gal. A major reason why humans make anti-alpha-gal antibodies is because we have gut bacteria with alpha-gal.

[@henriquezauba]

That a lot of people find this really interesting give me so much hope. Thanks.

[@steelmagnum]

Is alpha-gal also found in monotremes?

[@amanderps970]

"It's the song of the summer." -Only FACTS on PBS Eons!!!

[@invisiblepants6477]

It was an insidious plot by the strepsirrhines. It makes us easier to track.

[@bartbullock9742]

I wish there was more informative things just like this on KZbin.

[@johnnyswatts]

Really interesting stuff. However, you seem to imply that pigs also lack alpha galactose on their cells, but kind of gloss over it. Are suids also a-gal deficient?

[@petris90]

No, i think that you’re referring to the study they cited where they inactivated the gene that produced alpha-gal in a pig and found that it produced antibodies agains it.

[@firstprincipleswithsuhas]

Excellent talk, thanks for this!

[@drstone3418]

Wonder if immune system had more signals then Just foreign . . Maybe all kids of signals . Even stand down signals

[@bakoyma]

"That seems off brand" *lol* I love this guy

[@ryan49805]

Science just blows my mind. We aren’t supposed to know about any of this and yet we do.

[@Kleineganz]

Why aren't we 'supposed' to know?

[@dandork20]

Amazing video, as always.

[@emm6064]

I'm a little unclear: is this a single removal of Alpha-gal from the LCA of all Old-World primates, or parallel removals in the various groups due to the same selective pressure? I'm _thinking_ the later, but I'm not sure.

[@comeberza]

Its a common ancestor losing it and consequently the evolved species not having it

[@emm6064]

@@comeberza normally I'd agree, but we're saying that *all* od world primates only diverged *after* the split with new world monkeys? That every extant primate group in Eurasia died and were replaced with a single species that then diversified? Did this happen far enough back for that to be plausible? A plague is going to apply selective pressure in the same direction to *all* primate groups.

[@comeberza]

@@emm6064 I think the pressure was applied to that common ancestor population except those isolated. I think 30 to 40 million years is reasonable evolutionary time considering other factors would also shape the distinct species after the mutation

[@emm6064]

@@comeberza Ok, I actually went looking this time. Earliest crown catarrhines were (very) approximately 30 mya. Split with the new world approx 40 mya. So you are correct: plenty of time to lose alpha gal and diversify. I need to stop trusting my gut when it comes to evolutionary timescales. Not evey fossil primate in the old world was an Old World primate. Other groups existed too.

[@comeberza]

@@emm6064 ahha its fine! Its just what I understood from the video, didnt add anything else

[@tanuki88]

I love these videos so much! You always have such interesting questions!

[@RubbrChickn]

What happens to other mammals when they catch an alpha-gal virus? Do they identify the virus with a different signal on the virus' surface?

[@101magj]

Ngl that was something I was thinking as well. Because if it affected primates it should have affected other mammals right? Sadly I’m not an expert so I don’t understand lol

[@bbirda1287]

The virus itself was species specific to primates so wasn't infectious to other mammals.

[@kuitaranheatmorus9932]

I really enjoy these videos and I hope y'all are having a good day

[@nickvinsable3798]

Question: Birthrate. I honestly don’t believe I can word that better, thus I must elaborate. Certain mammals raises only one offspring at a time while others have multiple. I want to understand that…

[@ku8721]

The term is called Fecundity. I suggest you google it and learn more than I can teach you. But the rule of thumb here is the amount of care each offspring will need from the parent. The more time, energy, and care you need to place in each new baby the less babies the organism winds up having.

[@nickvinsable3798]

Okay, but I also remember that it was a pathogen that made mammals go from laying eggs to giving live birth. Thus I wanted to know if a pathogen was technically responsible for various groups of animals that’re outliers of that, @@ku8721…

[@ku8721]

@@nickvinsable3798 In this case probably not as that rule of thumb extends to many avian and reptile species as well. And naturally it makes sense, the more time and energy you need to devote to each offspring the less you'll have for more iterations of that offspring. Of course there are other factors such as available resources, but for the most part things like that affect generations. Now if the resources stay abundant or scarce for long enough it can change the evolutionary path of an organism which can mean lower or higher fecundity.

[@skyefirenails]

In a minute, Imma need y'all to post a short of Blake doing that Lizzo bit. I'm dying 🤣

[@cartercampbell9172]

I love this channel so so much. Also idk what it is but videos like this are especially fascinating to me. Thank yall for the videos

[@markholm7050]

Outstanding video! Thank you.

[@ScottJPowers]

it would be more accurate to say they couldn't detect a pathogen with alphagal because, to the immune system, it looked like any other cell. it's not like the immune system knew it was there but just couldn't do anything because an antibody targeting the alphagal receptor would also target the bodies own cells.

[@samarkand1585]

huh. It's explained in the video, yes

[@kuyachaswhub3086]

"Have you tried eat a clock. It's very time consuming." Oh shut up. I spat my drink because of this.

[@darthmaul216]

It’s time to stop

[@alliu6562]

Heads up boss babes, new name just dropped time to call yourselves the alpha gals now lol

[@AudraK]

Can yall do a video on how Lyme disease can cause autoimmune diseases and PTLD, causing you to feel ill years after treatment. Growing up I had Lyme disease then later developed hoshimotos and joint issues leading to surgeries. Now that I’m an adult I still feel like I am fighting the symptoms but with no help in sight. So little is known that it’s hard to find treatment. I pray that if more people know that more progress can be made in the field

[@zwiebeldogs]

"Girlboss"? You mean alpha-gal?

[@brooklyna007]

Maybe the longer lifespan of Cattarhrine primates in general made the trade off more with it for them.

[@tubebrocoli]

If an extremely deadly viral pan-continental outbreak is the reason for this adaptation, why are there no other mammal lineages who also lost alpha-gal?

[@chocobrowniewin]

could be the pathogen wasn't as deadly in other lineages. or it couldn't attack them because it was species-specific.

[@bludfyre]

Possibly, the disease was unable to cross from the primates who had it to those other mammals.

[@derrickthewhite1]

@@bludfyre in particular, it didn't hit the prosimians who lived in the same area and gave rise to bush-babies and Taisiers. Its possible it was species specific... the specifics of the break-off of new world monkeys would be helpful there, I think.

[@wcookiv]

Because the ability to jump between species is very rare. It only seems common because the ones that can pull it off tend to be the biggest threats to human beings on a global scale.

[@takodragionextream3625]

Last time I was here this early the universe just cooled down enough for matter to stop forming out of energy

[@michaelblacktree]

We humans like to think we rule the planet. But it seems like viruses actually run the show.

[@MossyMozart]

@michal blacktree - Yes, it does.

[@mharder5262]

I second The Real Mariguana's video request. Sounds intriguing.

[@drstone3418]

Maybe that's part of the reason for memopause

[@alfredogonzalez8735]

This is the kind of stuff that inspires me to be a scientist.

[@MossyMozart]

@Alfredo Gonzales - Please stick to it. The world needs all the great scientists it can get!

[@alfredogonzalez8735]

@@MossyMozart Thanks so much! Needed to hear that because im currently struggling to study and worried that im not doing enough for my research.

[@nitzan3782]

I think hitting infertility in our 40s when our lifespan easily reaches the 50s and can even reach the late 70s without medical intervention counts as a shortened reproductive lifespan.

[@tsm688]

humans don't generally live that long in the wild is the thing.

[@ku8721]

Yeah but remember we're talking evolution here so looking at humans after the dawn of civilization doesn't explain our evolutionary origins. The vast VAST majority of people didn't live that long before modern agriculture, medicine, or defense against both nature and the elements. The estimated average lifespan didn't get above 35 until the 16th century. Someone 50 years old would have been one of the village elders and that guy saw literally everyone else he knew growing up die from one thing or another while being the lucky one to survive. Its why many cultures placed emphasis on having many children, better chances of your family not dying out. And 10 years of non-reproductive life on 50 isn't that much especially when most people died before they experienced it.

[@vaokon9739]

@@tsm688 You have to remember than life expectancy is an average. It includes the droves of children who died before adulthood.

[@tsm688]

@@vaokon9739 so? even in relatively modern times (past 200 yrs) living to your ripe old 60's was pretty rare.

[@nitzan3782]

@@ku8721 Still, most animals don't experience menopause.

[@Isaac-gh5ku]

Now this makes me wonder what would humans with alpha-gal be like if that deadly ancient pandemic never happened.

[@ghostagent3552]

My main question now is, should we genetically engineer Alpha-gal back to its proper function for medical benefits or not

[@noticing33]

Exactly what I thought, I wonder what it will ACTUALLY do for us

[@dardar1862]

Love your program!!! 🙏 thanks