When Ancient People Changed Their Own DNA
Вставка
- Опубліковано 13 вер 2024
- Thank you to Rocket Money for sponsoring PBS. For more info check out rocketmoney.com... or scan the QR code on the screen to start managing your personal finances today.
Thanks to our ability to develop and share complex learned behaviors across generations - a thing we sometimes call culture - we have become the ultimate niche builders.
*****
PBS Member Stations rely on viewers like you. To support your local station, go to to.pbs.org/Dona...
*****
Produced by Complexly for PBS Digital Studios
Super special thanks to the following Patreon patrons for helping make Eons possible:
Melanie Truscott, Michael Roy, John H. Austin, Jr., Kate Huhmann, Alex Hackman, Amanda Ward, Stephen Patterson, Karen Farrell, Trevor Long, Raphael Haase, daniel blankstein, Roberto Adrian Ramirez Flores, Jason Rostoker, Jonathan Rust, Mary Tevington, Bart & Elke van Iersel - De Jong, William Craig II, Irene Wood, Derek Helling, WilCatRhClPPh33, Mark Talbott-Williams, Nomi Alchin, Duane Westhoff, Hillary Ryde-Collins, Yu Mei, 4th_phase, Jayme Coyle, Albert Folsom, Oscar Amoros Huguet, Patrick Wells, Dan Caffee, Stephanie Tan, Nick Ryhajlo, Sean Dennis.
If you'd like to support the channel, head over to / eons and pledge for some cool rewards!
Want to follow Eons elsewhere on the internet?
Facebook - / eonsshow
Twitter - / eonsshow
Instagram - / eonsshow
References: docs.google.co...
This also reminds me of the cultures who are able to hold their breath longer due to their history of sea diving for food.
And those in higher altitudes developing more efficient oxygen processing
@@christopherfisher128 Sherpas are the people of the Himalayas mountains. A 2010 study identified more than 30 genetic factors that make Sherpas' bodies well-suited for high altitudes, including EPAS1, referred to as the "super-athlete gene" that regulates the body's production of hemoglobin, allowing for greater efficiency in the use of oxygen.
Isn’t there a small culture of pearl divers that can control their pupillary constriction rate?
@@icarusbinns3156 It isn't Pupillary, that is the eyes, but you're not wrong.
The Bajau divers in Southeast Asia, have significantly larger spleens than other non-diving individuals of even recent genetic similarities, & can hold their breath for over 5 minutes. The "Jury" is still out on this as far as an evolutionary adaptation or a result of heavy usage & their hyper-specific culture.
For comparison, the Shima peninsula of Japan is home to the Ama, which are mostly female pearl divers, who can withstand long periods under water but have no major physical differences. A series of automatic responses kick in, constricting blood vessels, increasing blood pressure, and causing their heart rate to drop. While diving, pearl divers often see their heart rate at half its resting value, even though they’re swimming hard.
And lastly, there is Wim Hof who can not only hold his breath for a ridiculous amount of time, but withstand subzero temps without clothing. so, I guess with dedication & practice anything is possible ;) Cheers
@@christopherfisher128 I know it’s eyes. I wish I could remember the documentary I saw it in, but they can consciously control the size of their pupils. That muscle response isn’t involuntary for these people
If I am not mistaken humans habits of consuming alcohol for thousands of years was also a cultural pressure that resulted in a difference of people who can effectively process alcohol inside their body. There are some culture groups who will experience worse symptoms of alcohol poisoning (nausea, headache, facial flushness) than most other cultures worldwide. The name of this is an Alcohol Flush Reaction which has also been known to be referred to as the "Asian Flush".
Eons did a video on that, but primates can universally process alcohol. Humans ave extra copies compared to most others, but some human populations vary, like you're referring to.
(No one is seriously harmed, but other animals are easily harmed. An elephant could almost die drinking what even a alcohol sensitive human could easily drink)
If im not mistaken asians can have that variant that makes them extra sensitive to alcohol
@@Makabert.Abylon While I'm not saying this isn't true, I've never heard it before and I'm not gonna trust something like that without a source. Also, asian cultures have consumed alcohol for as long as everyone else. In other words, that wouldn't be relevant to culture impacting evolution, that would just be a mutation that causes an intolerance to something.
I have a bit of Irish in me ?😃
@Edepol vox has a short video on asian flush, something about immune response to more of a biproduct when they digest alcohol. But it doesnt affect everyone northeast asia
I’m jumping up and down at the citing of Padró et al. Such a great paper, proving the explanatory power of the cactophilic Drosophila model. I work at Evolution Lab at UBA-CONICET, so this was one of the few times I knew the people you cited. Excellent video as allways. Thanks! 🌵🪰
Please tell me more about what he's working on?
@@atamburlaine who do you mean? The author?
Glad that they mentioned Adult Lactose Tolerance evolved in multiple human populations independently throughout Eurasia and Africa.
5 times, though the European version is currently the most common
Disgusting.
Until this video, I genuinely thought it was only Europeans
@@aaron2891 Europe, Twice in sub-Saharan Africa, the Middle East and Central Asia
@@samsmith4242 Could you please tell me the groups? I know Northern Europeans and Fulani but I wasnt aware of others
I wonder if someday someone will research our gene in relationship to addiction. We have been producing alcohol (mead, ale, wine) for a long time. Might give it a better understanding why some people react differently to it.
Alcohol is actually a great example, as it’s toxic to our bodies and we’re not really intended to consume such high quantities of it. Interesting to think about what effect it may have on our genomes!
@@worldsboss Also with spicy foods. The chemicals deter most other animals from eating the plants, but not us humans.
People who come from regions with longer exposure of alcohol such as Italy, have lower rates of alcoholism. Vice versa.
@@tara44789 big if true
Some cultures are missing the gene that helps your stomach metabolize alcohol more efficiently (they produce less of an enzyme needed).
I'd say songbirds are a great example of culture and evolution intertwining. Male songbirds spend a lot of time practicing their technique and memorizing and imitating other males, so it's not just genetic. But their capacity to do so is.
Some species of ants have also learned how to farm and evolved around that. So they have their own culture affecting their evolution.
so, maybe one day our descendants will have genes to digest microplastics and breathe nanoparticles 🤔 ?
We'll probably have to create that gene artificially... It would be worth it to save ourselves...
🙄
*safely
There are bacteria that can break down some plastics, so if they got into our stomach and gut biom, that could happen.
@@TragoudistrosMPH Something even if it happened, wouldn't really help us. CRISPR is big but it doesn't really have any effect on people already around.
Thinking about the amount of work that has to go into making this video blows my mind. The narrative and narration was excellent. This was a fun video to watch. Complex yet not too deep that I had to repeat 5x (only 2 times for me in some areas lol). Thanks to everyone involved in this video (and yes that means patreons and all) ;)
This is an excellent episode that communicates a complex topic with all the right nuances. It doesn't generalize the evolution of lactose tolerance to "us" or "humans", which is how the topic of lactase is usually presented. I love the examples of genes for the breakdown of starch and genes for processing hallucinogenics, so those of us from lactose intolerant populations have some examples of our evolution being shaped by culture too.
90 likes
Genes that affect the expression of proteins useful for processing toxic alkaloids need not have been selected for on the basis of ceremonial usage of hallucinogenic cacti, though. That same region of South America is where the potato originated, and potatoes contain solanine, chaconine, tomatine, and possibly a few other toxic alkaloids. More ancient varieties would likely have contained a lot more of those compounds than modern varieties, and I think it's pretty safe to suggest that many more potatoes were eaten than cacti.
Yes, although humans have methods of removing the alkaloids in potatoes (cooking and soaking) while they intentionally digest the cactus
That's a really interesting insight, but can you cite a source please?
@@olha_ Most of my comment is semi-speculative in nature. I'm not saying that gene expression related to processing plant alkaloids definitely was driven by potatoes rather than cacti, merely pointing out the plausibility of that as an alternative explanation. However, if there's a specific claim you want to have cited, identify the claim more precisely and I'll see what I can find.
@@bobbun9630 it's the very statement that gene expression for alkaloid processing is influenced by the potatoes rather than cacti. I totally agree that this is more plausible from a common sense perspective but was wondering if there are any studies or further reading on this. Thank you!
Here's hoping we continue to shape our future with considered and measured steps
No, return to monke
By measured steps you mean "quarterly profits", right?
@@Unpainted_Huffhines reject humanity
Capitalism doesn't work that way heh
Most likely genetic editing and then AI hive mind.
Please do a full episode on Lactase Persistence.
It's so poorly understood, and so many people think they are just sick, or keep drinking milk thinking it's healthy for them.
Northern Europe and Central West Africa are where 2 of the main genes mutated. A 3rd in the middle east that's not strong exists too.
Asia, Americas, Australia, and Pacific regions don't indigenously have such a gene, unless they are descendants of one of the above people with the mutation.
Super fascinating and a great PSA.
I'm Asian and still drink milk almost daily. Albeit to just a glass a day. I haven't dared chugging down a gallon.
afaik it’s not unhealthy to consume dairy if you’re lactose intolerant, but i’m lactose tolerant so i don’t have experience with that. i do have experience consuming allulose and sugar alcohols in decent quantity and that seems like it could work pretty similarly, basically as long as you have enough in your diet your gut will adjust to the fermentation of them, eating it when you don’t consume it much would cause more issues because your gut isn’t used to it
Lactose intolerance can cause a person to develop diarrhea and stomach upset. Intolerance is not the same as allergy. It's not Anaphylaxis. But it can still make you feel really bad.
It's not the only thing that can make you feel bad drinking milk. There are times when dairies give a lot of antibiotics to their cows. I think more and more these days the do it only if they need to keep the herd from catching a disease.
But I can tell if there's been an increase in antibiotic use: I get diarrhea like when I take antibiotics. And it doesn't matter the milk. Acidophilus milk at the time still gave me diarrhea. So for a while I got Simple Truth Kroger brand because it uses milk from only grass-fed cows and has no antibiotics. And it agrees with me just fine.
A container of milk can say on the label all it wants about not using antibiotics, but you can't fool my body.
You missed the herding populations of east Africa that drink milk multiple times a day and have been doing so for thousands of years. For example, the Maasai people in Kenya are definitely lactose tolerant.
@@morgan0
It’s not that it’s unhealthy (unless it leads to terrible diarrhoea and dehydration), it’s just very uncomfortable.
Whilst watching this, I remembered those ants that farm a type of fungus, & wondered if they have have had an effect on their genome in a similar way to what was described in the video with regards to humans.
Probably became more sensitive to detecting the pheromones that fungus releases instructing them which foods it needs and which stuff they brought is poison. I keep telling people the world is really like pokemon/avatar, the complexities of the creatures and ecosystems around us are awe inspiring
@@jeffreybright6354 Its funny because Avatar's world is heavily inspired by the intertwined ecosystems of earth.
They have their own culture of fungus that doesn’t grow naturally and they are a separate species of ants so yeah. :)
One of these days this channel will need to cover the Moken people (aka as sea-nomads).
They have partially adapted to be able to see underwater far easier than the rest of the human population.
The kids that open their eyes in the ocean to hunt and they dilate as you watch to adjust to seeing underwater is mind blowing
This may be one of my favorite episodes yet. Such an interesting topic and very well presented. You guys are awesome!
This all rings so true. My people have specially adapted very quick pupil contraction and dilation which aids in quicker identification and capture of prey in late night visits to the refrigerator. Speedy pupil dilation following the closing of the fridge door aids in safe navigation of dark hallways and stairwells. Love your videos. Miss your podcast. Keep up the great work!
Takling about cacti and showing a Euphorbia instead... Twice! 6:21 and 8:21 Come on guys!
Convergent evolution.
Isn't the role of culture in shaping DNA really common across animals? I mean, so many animals have body decorations, exaggerated body parts, behavioural traits (esp. courtship), nest building techniques, and so many other things only because of potential mates preferring things a certain way. I think culture plays a massive role in plenty of other animals.
I think how the video addresses this is specifying how regularly humans do this. Making different kinds of termite mounds doesn't cause genetic change very often, if at all.
Countless changes in humans in just the last 10,000 years, but also consistently going back another 400,000 years.
The only real difference is that humans can do it on purpose. Look at "cultures" that developed after long periods in "extreme" environments. High altitude, deserts, the Arctic, Primarily animal based diets, & even island or urban populations.
That was my first though as well. There are survival pressures (consumption of poisons, novelty food sources, dangers of new environments) where the survival comes from literally not dying before reproducing. And then there are cultural pressures such as atractiveness of sexual partners, social bonding within the group, co-parenting and so on. In these cases, the question isn't whether an idividual dies or not, but how successful they are in securing a mate and raising the next generation up to their adulthood.
Yeah. I really dont think there is any fundamental diference between human culture and any other animal behaviour
@@Dinofaustivoro The fundamental difference is that most of those animal behaviors are instinctual, whereas human behaviors associated with culture are all learned. That's really what culture is -- collective knowledge that's passed down from one generation to the next. A break in that generational chain means that knowledge is lost forever until it is (maybe) rediscovered.
Thank you for the fantastic video Michelle! And the rest of Eons :)
Seconded. Love their content
Great episode! Beavers come to mind. They build their own niches... And fruit eating birds and tapirs dispersing seeds and growing forests. Are there other animals that do the same?
Read "The Extended Phenotype" to find a lot more examples of this phenomenon.
The way Michelle says Chile and Argentina is so nice!
@Maclin Kastex exactly my reaction. At the very least, she has latin roots
@LuisSierra42 Michelle does have Latin roots. They are Latinx.
as an English-only speaker, I had a moment of whiplash and didn't catch Chile at first lol
In discussing "cacti," y'all showed a succulent euphorb. Eating that would kill you rather than make you high.
you wouldn't experience euphorbia?
Our built environments are such a huge part of our cultures that definitely change pressures on us as well. By enclosing ourselves from biodiversity, we're totally changing our relationship with both beneficial microbes and pathogens. There's a fascinating book on this topic
called Never Home Alone by Rob Dunn. It's probably too soon to know what these changing pressures are doing to our genetics, but I can imagine the process will reward those who can do better with fewer lil friends and more lil enemies.
The children who could continue to drink milk obviously had a survival advantage.
An advantage that would not matter if husbandry was not invented... how are you missing the point this badly?
Likely fewer broken bones resulting in a decrease of deformities/infections.
Wow that comment at the top of this thread sounds like a dog whistle to racists.
@@kendallbein5616 How is the ability to drink milk a 'dog whistle' to racists?
@@kendallbein5616 racist against what? Lactose intolerant people?
You're funny.
If you do make a video on lactose tolerance don't forget to include certain domestic animals, like cats, who also gained adult lactose tolerance by living alongside humans.
I've never heard of a gene for that, just anecdotes from people who say "we've always given our cats milk".
Cats who drink milk have indigestion and loose stool.
A gene has to randomly mutate and be passed on, it can't be 'gained' by drinking milk.
@@TragoudistrosMPH I dunno, one of my cats go loco when he sense me getting milk before bedtime. Like, he'd bug me until I finally give up and give him what he want. His stool still firm. The other cat don't care about milk and only drank some when she was pregnant.
I personally have cats regularly scratching (waiting patiently really) for their daily dose of milk.It's you who believes in old wives tales Thagou.
@@TragoudistrosMPH Just a guess, but I think that cats often get fed WAY too much milk. By weight, a capful for them is like a half cup for us.
Incredible. I was literally just thinking about this very topic last night, and Lactase persistence was exactly what came to mind... One of the best episodes, really! Loved it, and, of course I'm happy to see the sponsorships coming in, you guys definitely deserve it, but... isn't this... PBS? Kinda unsettling seeing that kind of paid programming under the PBS banner, idk...
I'm guessing it's because PBS needs the UA-cam shows to support themselves instead of giving them full funding. It's a way to enable more creativity in new platforms without having to spread the budget too thin.
time to get wings
Imagine how tiring it would be to flap them though
@@MonkoK14 ez, u just try harder
@@Ricee__ true
I've been drinking cases of Red Bull, but I haven't gotten wings. Just kidney failure.
This makes me think about animals that engineer to craft their niches. Elephants curating grassland by removing trees, beavers and their whole deal, termites farming fungus, there's probably a smart fish I don't know about, etc
It's me I'm the smart fish nice to meet you
Fun fact, we aren't the only species who's evolution was driven by culture. This type of evolution is also very prevalent in orcas, more-so than most other species besides ourselves.
Hawaiian crows, also
Wow this was so interesting! Thanks for sharing!
It's actually insane how interesting humans are once you look at them like any other animals. We basically removed most of our instincts and replaced them with culture which basically allowed us to adapt to any environment. Other animals took many generations to develop new instincts but we took just one. Nowadays it's a negative because the world changes so quickly but back then it was a truly miraculous advantage that only a few animals could possibly imagine.
I agree! But I think it is unscientiffic to assume our culture is somehow not a product of enviroment and evolution
@@Dinofaustivoro Culture is most definitely a product of our environment and evolution. I don't where you thought I was denying that.
i think maybe we've kept most of our instincts but added layers of culture
This is an absolutely fascinating subject. Thank you for exploring it.
I love EONS!!🤯
I was so surprised to see your old and up to date video posts on the Local Now App! I love watching these on a bigger TV than on my smaller monitor! Congrats!
Let's hope we manage to adapt to the huge amount of "Forever chemicals" they just found in freshwater fish. Might as well eat up tho, as we are already full of microplastics...
Forever chemicals are everywhere, not just fish. Every baby born now has forever chemicals in their body
Hey, I love your videos and have been watching them since I was in high school, and they stay with me as I’m at college. I have been thinking about this for the past few days, and notice that you haven’t made a video on this yet: how did insects go from many-legged creatures to ones with just six? How did insects lose their legs?
This is a fascinating question but I doubt they'll do a video on it because I don't think anybody knows the answer yet. The origins of insects are still pretty mysterious.
they mispronounce john davison ng's name every dang time and he STILL gives them $150 a month. shoutout to a real one.
This was very interesting.
Fantastic sci comms per always!
Years ago I woke up in the night saying, "I believe in Quantum Evolution!"
You have essentially proved that my belief is not folly.
Thanks.
Excellent Video. Very Accurate!
The alkaloid one made me remember. In history class, it was said that when Europeans came to the Americas and brought alcool, while we were more resistant, the indigenous population was more susceptible to get drunk and addicted. If it's true, I don't know, but I remember it was said
Simple carbohydrates vs. complex carbohydrates.
Pretty sure everyone was at least drinking corn beer. Regionally, pulque is a thing, too.
I checked, there's a Wikipedia article on Alcohol and Native Americans that includes a variety of starchy substances pre Colombian cultures fermented.
Dogs are also capable of consuming relatively high amount of starch. Do they have multiple aym1 genes or do they have other adaptations that allow for the trait?
Also did humans relationship with dogs also similarly change their evolutionary pathway?
Dogs are bred by humans, of course we changed their evolution. Look at breeds like pugs who suffer from chronic diseases right out of the womb because of the unnatural selection of breeding
cats also seem to digest rice well, so i was wondering the same question with them
Fascinating. Thank you.
Plenty has been said about us shaping dog genetics, but what about dogs shaping our genetics?
It’s interesting to me that we use the word culture and its cognates to talk about things like bacteria in Petri dishes, changing dairy into yogurt or cheese, or changing a landscape; all things that get transformed into something new
Organisms really are just like water: we always eventually change shape to fit our environment, and we're never in a stabilized state. We're always changing.
Wow this was one of your best videos! You make evolution a compelling and inviting topic!
Do humans have an evolutionary attraction to fire? Other animals do not seem to behave as we do.
yeah totally. few animals approach fire.
UUAUUU!! I LOVED THIS VIDEO🤩💯
Almost everyone with indigenous ancestry in my family (Argentina) is lactose intolerant, simply because in the New World, people didn't drink cow's milk until colonization. If you were born in latinoamérica, from a mestizo/indigenous family, it can probably be common cause of lactose intolerance.
Fascinating.
PBS uploads save my evening each and every time
Recent research expertly explained.
Thanks.
So how’s the current trajectory for humanity?
look up Idiocracy (2005)
We are all going to die. That's the prognosis
Josh, are you trying to depress us? 😜
Screaming toward self-inflicted obliteration, last time I checked.
It's very important for people to understand natural selection≠evolution, and that natural selection is one of many selection processes of evolution. People have this idea that evolution always takes millions of years to make any noticeable change, but they're thinking about mutation, and even then, it's not true for everything (fruit flies, viruses), and evolution could make big changes in a matter of generations if the genes for a good allele were already out there, like the classic example of white and black moths in the UK during industrialization; if a new selective pressure appears, and let's say, humans now benefit from being 50cm tall, and there were like a few dozen people that tall out there, in a few generations they'd be majority, a species can change DRASTICALLY in times that most people don't think are long enough for evolution to happen
This is my favourite show on UA-cam
One of the most interesting gene transitions is the loss of Y chromosome diversity as aggressive groups became dominant across large expanses. What might the world be like if it were not the aggressive Ys that won?
Hallucinogens on pbs?! It's about damn time! More please.
I love this channel so much!!!!! The level of beauty explaining it all!
How you say Argentina is so perfect
Just another great episode. Moar of this plz.
What a great UA-cam channel!
I find the modern, hyper complex and constantly changing techno-culture to carry with it a heavy cognitive load. It seems to be hovering around the threshold of what a human can keep up with. I find myself unable or unwilling to do it. And the older I get, the less willing I am.
So it appears that there is a very strong selection pressure at work that favors youth and high intelligence.
I suspect that this will create greater, not less, inequality in the world.
I don’t think that’s true at all.
Fitness is defined by an organism ability to reproduce. Do you think intelligent people are more likely to have more children? Doesn’t seem true to me. If anything it’s the opposite imo
Evolution does not favor people who are more “successful” or happy, it favors those who reproduce more.
@@willw5868 there is no doubt that there are unprecedented dysgenic trends taking place right now, but that doesn't change the fact that there are other pressures in operation that are redistributing power and wealth.
We don't know how this will all end, but it seems that there are selective forces in play that are splitting populations into separate genepools.
@@casek6930 yeah I would tend to agree with that. If you look at trends like online work and suburbanization, it seems that people are becoming more and more isolated within their social classes.
My big concern would be gene editing. With how strict governments on banning it, I fear that only the ultra wealthy are going to have access to it when it be mes viable. Which would lead to a race of super enhanced beings who could limit access to genetic engineering to their own class, dividing humans strictly into normal and enhanced classes
@@willw5868 What would be the benefit of limiting gene editing? If you can create super enhanced beings after a few doctors appointments, the added value will be so high it would be insane not to democratize that tech. Many social problems could be solved.
@@guitarazn90210 yes my point is that the current policy IS to ban or heavily restrict it. And when you effectively ban or heavily restrict something, only the powerful are going to have access it. So I agree with you in that gene editing should be widely available, but it doesn't look like that is going to be the case with current regulations
Don't laugh at fruit flies! 👍 They reproduce quickly, they live 2 weeks, and they have 4, well-mapped-out, simple genes. This makes fruit flies easy to use for genetic studies. They are used all the time in university genetics classes.
These are excellent subjects for study!
I found this video and topic really interesting on a personal level. I am lactose intolerant and have known this since about 1990 when it was confirmed by endoscopic biopsy.
My mother cried and apologised for making me, and my siblings, drink a pint of milk every day. Haha. I am 38% Asian on my paternal side and told her it wasn't Her fault.
Her mob are Anglo Celtic milkmaids and brewers.
Interestingly, dogs produce much more amylase than their wolf cousins, even though they are technically the same species. Wolves have a much more carnivorous diet than dogs, so dogs have evolved to tolerate starches like their human companions.
One of those graphs mentions the Barí people. I've met Bruce Olson, who's lived among the Barí (aka Motilones) for decades.
Love the human episodes! (And the others too)
This was really amazing; I love this channel.
Bravo on the Argentina pronunciation.
Going through the comments I'm astounded that nobody has mentioned fire and its consequences on culture, digestion and genes to support that new diet.
It's the cows, man. The cows are not what they seem.
😁
ಠ_ಠ
@@madcow3417 Oh,man, now you're following me? I won't tell anyone.
Interestingly, my youngest son was born lactose intolerant (we finally found out why he was so sick, and not growing at 4 weeks old). He has actually been slowly out growing it though. He can now tolerate regular cheese and yoghurt (which has very little lactose thanks to the bacteria that creates it). And he can tolerate some regular cream and milk used in cooking. But I don't push it too much, because the tummy troubles aren't worth it.
Wow, I've never heard of an infant who was lactose intolerant. That must be hard. I'm pretty sure I'm lactose intolerant myself and it is basically only triggered by milk and ice cream. Butter, cheese, sour cream, and other dairy products that are more processed don't set me off much. I'll still eat ice cream anyway but I'm old enough to understand the consequences. Jokes aside, I'd experiment a little with dairy products to see what does and doesn't work well once your son is old enough to get to the toilet on his own. I'm not a doctor but I don't think small amounts would really hurt.
babies are born with an immature digestive system. some (rare) babies are born without the ability to properly produce lactase, and as they grow and mature, they slowly become able to produce more of it. I was such a baby xD
I’m wondering how that works if a baby needs to breastfeed. Would they react negatively to breast milk?
@@wendys9500 yes. Because all mammal milk contains lactose. Babies born with lactose intolerance used to just slowly starve to death, in what was known as failure to thrive (one cause of).
These days babies with lactose intolerance can be given lactose free formula.
One super interesting thing is the North Sea Population Replacement Hypothesis. Whereupon the economic upper 1/3 of the southeast english and low countries population outbred the lower 2/3 of the population three times over 800 years, completely replacing them. An amazing case of self-selection.
Not getting any hits for "North Sea Population Replacement Hypothesis". Sounds interesting. Got any hints for more info?
Sherpas are the people of the Himalayas mountains. A 2010 study identified more than 30 genetic factors that make Sherpas' bodies well-suited for high altitudes, including EPAS1, referred to as the "super-athlete gene" that regulates the body's production of hemoglobin, allowing for greater efficiency in the use of oxygen.
Would the invention of writing have triggered similar changes to accomodate for the different workload our brains needed to handle? And would different writing systems cause different adaptations? (Like the consumption of milk lead to lactose tolerance, but via different pathways?)
Writing actually reduces mental workload. Some of the earliest writing was for taking inventory. It requires more mental capacity to memorize large lists and perform mental calculations than writing it down.
I really don’t think writing had that much of a survival impact for most of history. Average people only became literate in the last few hundred years. Until recently only people in certain specialization needed to read to survive, farmers, who were the large majority of the population, didn’t.
what i’d like to know is how i ended up lactose intolerant when nobody else in my family is. my lactase genes just didn’t get the memo apparently
I wouldn't go getting any paternity tests.
@@necessaryevil455 unfortunately i was a petri dish baby so i know exactly who my dad is (barring a career ending mistake by the fertility specialist)
@@kaitlynoddie9649 I'm blue eyed. Blue eyes recessive. Parents and sibling brown eyed. I just got a double dose of blue eyes. And of course every cancer gene there is.. 5th BCC and breast cancer simultaneously is so much fun.
I would guess both your parents carry the gene for intolerance but recessively (it didn't express in them because they only got one copy of the gene (s)). The other option is spontaneous change, which is also possible - there is more likelihood of genetic changes in "test tube" babies - they think because the process is actually stressful to the embyro...
In my case the gene damage is as as a result of my sperm donor - worked in agrochem his whole career - DDT, Dieldrin, the ingredients of agent orange, paraquat, diquat - you name it. Cleaning up spills with yard brooms and a garden hose.. 🤦♀️. My three young neices probably have the same genes - yay for dead before 30.
Milk is disgusting, you're not missing much
@@rosiehawtrey interesting, i didn’t know that but it makes sense that ivf would be stressful to an embryo
Evolution only cares about our reproductive fitness, so cultural changes that effect that are going to have the greatest impact. For example: our cultural shift to widespread contraceptives.
And it's difficult to talk about, but I expect that our ability to minimize infant and maternal fatality with modern healthcare is actually making us less naturally fit over time. We probably have more detrimental genetic diseases now than we did before modern medicine, because of how it has allowed us to live with those diseases and pass them on to the next generation.
I did a presentation on this last Friday lmao even the graphs are the same ahah love it
They're gettin the bees high, man! That's the kind of science we need more of!
Can we talk about Thylacosmilus?
Thanks Michelle for keep pronouncing Chile and Argentina as Latinos do!
¡Ai Dios mío! I noticed it too.
I thought it was pretentious.
highlights the question of the vision of future humanity.
Gosh! You're my favorite YT channel.
DO THE MILK EPISODE!
fascinating!
Ben and Jerry's is adaptive evolution? Beautiful...
How about a video on evolution's multiple experiments with flight in theropods?
Our DNA changes even as we age. The 'best' samples of our DNA would be when we're younger vs older, when having kids. This is a great video that should fundamentally change peoples world views. If anything else, it just means that having a diverse population is essential for the healthy evolution of our species.
My theory on why religion and spiritualism are such powerful forces with human behavior is in line with this too. Our ancestors have worshiped things they cannot see and things they cannot ever really know for so long that we now currently have a genetic defect in our brain that makes us highly susceptible to believing in anything if it makes us feel better or safe. I also believe the races can be explained through the environmental pressures of where the first tribes made their homes and the cultures they grew. There is no better than anyone else there, it's just being better at living in a certain ecological system than another race because they evolved to do so.
🙄
Religion:
1) searching for pattern and agency is evolutionary adaptive (seeing agency in forces of natures has low fitness penalty, while overlooking agency when someone is plotting has high fitness penalty)
2) Using common tribal religion practices as marker of in-group / out-group memebers is effective adaptation in group level selection.
" it's just being better at living in a certain ecological system" Unless of course the ecological system puts stronger selection in favour of a feature that right now is being valued. Then we're drifting in to a taboo teritory.
I should probably wait until the video is over but I can think of a way we changed ourselves. The coming of the Pill changed which men women are interested in. That changed us.
Interesting! Great watch as always!
You pronounces Chile and Argentina in spanish, i am happily surprised :D
Drink cactus juice! It'll quench ya. Nothing is quenchier. It's the quenchiest! 😄
4:43 made me very concious of the fact that I'm watching this while eating a pizza bagle with eggs and cheese
I like you. And this is a good video. Thank you.
Almost more interesting than our genetic interaction with "milk", to me was the part about the genetic interaction with hallucinogetics ( or mental altering substances in general).
We knew about the differences in alcohol processing enzymes between populations, and this may be a part of genetic-culture co-evolution.
But what about substances like THC (Cannabis), Psylocibin etc ? How or why did these develop interactions with our instinctive(?) needs to regulate our emotions by extrinsic means (instead of meditation for example).
To my understanding the use of these substances alters our brainfunctions so that we feel better afterwards. And maybe this is all that is needed ( as shown with Ketamin- and/or electrotherapy under narcosis). Yet many populations have developed whole religions and spiritual practices out of that, since everything they can "measure" in these substance induced states is their perception, i.e. emotions/visions/thoughts. (Or maybe the believed this was the whole effect by itself that increased their well-being.)
So is religion/spiritual belief in these populations just a byproduct of substance consumption? Or were their beliefs mandating the substance consumption to experience the abstract thought on a perceived level? Or both? Or , even, was all of this just the consequence of initial psychomedication which had nothing to do with any spiritual reasoning at all?
@PBS If you haven't yet, please think about dwelving into this matter a little bit more. It's just too fascinating, since it connects history with modern society on such a deep basis that makes it almost practical knowledge for the future as well :)
It is very interesting that science continues to refine and expand on Darwin's original theory of evolution. These cultural effects are something Darwin could never have imagined.
yup. Darwinian evolution is necessary, but not sufficient to explain what we see in life.