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            I was surfing around the internet the other day and came across the Quintessential Quintuplets manga, which has an anime currently airing.  Its harem comedy humor isn’t really my thing, but I might watch it if it gets an English dub at some point.  What did interest me was that we learn that the quintuplets are monozygotic quintuplets, so what exactly does that mean and what does it have to do with twins and other instances where there are multiple births, aka the mother has more than one child at once?  Now since we are going to be talking about births and babies let me quickly get some terms out of the way.


            Fertilization is the process where the male sex cell or sperm, fuses with the female sex cell, or egg.  Each of the cells contains 1 copy of chromosome #1 through #22.  The egg also contains an X chromosome while the sperm will contain either and X or a Y.  When the sperm and egg fuse, they create a cell called a zygote.

            It is the zygote that then develops into the baby, which typically takes about 9 months.

Multiple Births

            Normally we humans have 1 child at a time, but there are instances of multiple births where more than one child is born at the same time.  The most common type of multiple births is twins, which are not all that common.  In the USA the likelihood of having a twin is around 16.7 twins per 1000 births according to a 2012 study.  However, interestingly enough the Yoruba people of western Africa have around 100 twins for 1,000 births.  Now there are some genetic traits involved in twins as women who have a family history of having twins are more likely to have twins.  However, in the case of the Yoruba people, it is thought that their diet plays a large role in their high rate of having twins.  This is because the species of yam that is native to western Africa is high in phytoestrogen (plant estrogen), which is theorized to affect female physiology regarding childbirth, at least according to studies done in 1995 and 2008.  On the opposite end is southeast Asia, which has a very low rate of twins at 9 twins for 1,000 births.

            Next there are triplets where three children are born at the same time, and I had to do a bit of digging to find some data on the chance of having triplets.  The chance of having triplets or higher numbers of multiple births in the United States in 2017, according to the CDC, was 0.33 sets of triplets or more per 1,000 births.  Additionally, the rate appears to be decreasing since at least 2010 according to the data.  Now for the big question: how do multiple births happen?


            Normally the mother only releases 1 egg at a time, and that one egg is fertilized, leading to the child that is then born after 9 months.  However, sometimes the mother can release more than one egg at a time, and it is possible for both eggs to be fertilized, leading to two or more zygotes, and multiple births depending on the number of eggs released.

2 eggs = dizygotic twins

3 eggs = trizygotic triplets

            It is possible to have more, but as you saw in the previous section it is highly unlikely.  In any case what you might scientifically call Dizygotic twins, we commonly refer to as fraternal twins.  In layman’s terms they are siblings that are born at the same time.  They can both be the same sex, or be one of each.  For an anime example we have Johan and Anna from the Japanese psychological thriller, Monster.


            Mono means 1and monozygotic means 1 zygote which is the norm in human reproduction, so how do you get two or more children from 1 zygote?  To answer that I need to briefly touch on the initial stages of human development.  After the egg is fertilized and becomes a zygote, it begins to divide; 1 cell becomes 2, 2 becomes 4, and so on.  This continues until the zygote becomes a morula, or ball made up of around 200-300 cells.

            The morula then undergoes a transformation where a cavity forms inside of it, becoming a blastocyst.  Now the reason that I had to go over this is to explain where monozygotic or identical twins come from.  During the early stages of development, it is possible for the morula and/or blastocyst to actually divide in half, forming a completely new morula or blastocyst.

            As we can see in the diagram because of the split happening during the early stages of development monozygotic twins are identical because they share the same DNA, hence the name identical twins.  We can see this with the Hitachiin twins from Ouran Highschool Host Club.

Warning Extra Science Content

            Twins are often used in various biological disciplines like psychology to look at whether a particular phenomenon is caused by genetics, the environment, or some combination of the two.  Fraternal twin studies can be used to determine the extent to which genetics influences a particular trait, because theoretically the twins being born at the same time would share near identical environments.  On the other hand, identical twins, especially twins separated at birth can be used to determine the extent the environment influences a trait as they would be genetically identical.  NASA actually performed their study of how long-term space flight affects the human body using the identical twins Mark and Scott Kelly.

Extra Science Content Over

Triplets and Quadruplets

            When it comes to triplets or even higher numbers of multiple births, they can be completely monozygotic, completely dizygotic, or some combination of the two.  As previously stated, triplets are much less common, especially monozygotic triplets where the embryo splits three times.  However, we do see them in anime and my example today is the Chi-chans from A Centaur’s Life.

            Quadruplets can also be monozygotic or dizygotic and are even more rare than twins or triplets.  I do remember reading an article last year about a woman who had identical fraternal twins.  Now you might be thinking but wait I thought you said identical and fraternal twins are two completely different things.  And the answer is yes, identical and fraternal twins are different things, but this will make sense in the end.  The mother was going to have fraternal twins, but then each fraternal twin split into an identical twin, so 2 became 4, hence calling them identical fraternal twins.  Now when it comes to anime I could only find one example of quadruplets, Syaoran Li’s sisters from Card Captor Sakura.

            Neither the anime or manga gives any information as to whether they are monozygotic or dizygotic quadruplets, but I think I can safely say that they are dizygotic twins.  This is because they do not share the same eye color, despite otherwise looking nearly identical.  Also, I know that certain environmental factors can cause eye color to change with age, which could explain their different eye colors.  However, we know very little about the sisters, so I would not want to speculate any further on that.


            Yes, it is possible to have quintuplets naturally without the help of modern medical technology.  However, they are very rare and many times not all of the children survive infancy.  This is due to the fact that they are born prematurely.  The first set of recorded quintuplets known to have survived past infancy were the Dionne quintuplets, who were born 2 months premature in 1934.  Additionally, the quintuplets were monozygotic or identical.  Now when it comes to the odds of having quintuplets, I couldn’t find any sources I would completely trust for scientific data.  One website said that while having quintuplets is possible, calculating the odds is impossible due to how rare they are, which makes sense to me.  Long story short, yes monozygotic quintuplets are possible, but the odds are very, very, low.

            Now this brings us to the Quintessential Quintuplets, who are stated in the manga to be monozygotic and it is entirely possible according to real world science.

            But, wait a minute, you said that Syaoran’s sisters were dizygotic because of their different eye colors and the Quintessential Quintuplets all have different hair colors.

           That is a fair point but in the manga the Quintessential Quintuplets all share the same hair color most of the time and the manga tells us that they all have the same hair color.  The hair colors were probably changed for the anime as a way for us to easily tell the quintessential quintuplets apart from one another.


            I hope that you enjoyed my explanation of multiple births and yes, the quintessential quintuplets are entirely possible.  So, I will be calling this one confirmed.


The post The Quintessential Quintuplets appeared first on Anime Science 101.

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inside of a reality marble

            While at the Colorado Anime Fest, I was asked to look into the science behind some of the powers in the Fate Series.  At first, I wasn’t really sure what I could do with it, because it is a magical series with crazy powers and not very many good reference scenes to measure what is happening.  Plus, there is the fact that I haven’t watched much of the Fate series beyond the original anime series from the early 2000’s and the much more recent Fate/Apocrypha.  That being said I went for a run the other day and got to thinking.

Just what is a Reality Marble?

            In the Fate series a Reality Marble is essentially a pocket universe created by a mage/servant through the use of magic.  The new universe is completely separate and sealed off from the real world as long as it is active.  (I know in Fate series canon it is a bit more complicated, but the basics are sound.)

How big is a Reality Marble?

            There are no hard numbers on just how big a Reality Marble is in any of the Fate series, but there are a few screen shots that will allow me to speculate a bit.  Archers Reality Marble, Unlimited Blade Works is a hill in the center of a field filled with swords, seen bellow.

            In this particular image we can see all the way to the horizon.  In the real world when you are standing on a flat plane the horizon is 4.7km away for an individual who has an eye level of 1.70m.  I know that Shirou is technically 1.67m tall, and there is the hill to contend with but we don’t know how high the hill actually is.  As a result, I am going to round the distance up to 5km even to make the math a little easier.  Additionally, it is safe to assume that they were summoned to the middle of Unlimited Blade works, thus it has a diameter of 10km.

What is the shape of a Reality Marble?

            The next big question is the shape of the Reality Marble; is it a sphere, a dome, or something else entirely?  There is no absolute way to be sure; however, there are some clues in Fate/Apocrypha.  Achilles, the famous hero from Greek legend, has a shield (Akhilleus Kosmos) that while not technically a reality marble, is described as being very similar to one.

            The shield defends against attacks by creating a miniature world.  In Fate/Apocrypha the world appears like a sphere from the outside.

            I know that it is not a Reality Marble but I think it is close enough to one to safely assume that a Reality Marble would have a spherical shape.

Volume of a Reality Marble

            It we combine the diameter measurement from Unlimited Blade Works and the shape from Akhilleus Kosmos, we can start to get an idea of how big a Reality Marble is.  (FYI- I will be converting km to cm to make the math easier down the road.)

Volume of a sphere


V=(4/3) x π x (5,000)^3

V= 5.24×10^17cm^3

Mass of a Reality Marble

            Since people can survive inside of a Reality Marble, it is safe to say that it has conditions similar to that of Earth, which means I can use the average density of the Earth to figure out how much mass is in the Reality Marble.

Mass of the Reality Marble = Density of the Earth x Volume of a Reality Marble

Mass = 5.51 g/cm³ x V= 5.24×10^17cm^3

Mass = 2,887,240,000,000,000,000 grams


Mass = 2,887,240,000,000,000 kilograms

Energy needed to create a Reality Marble

           Leaving aside the energy to create a pocket universe, the Reality Marble leaves the real world completely unaffected, which means that all of the mass in the Reality Marble has to come from somewhere.  That somewhere in this case is energy, and the energy needed to create all of the mass can be calculated using Einstein’s Theory of Relativity, or E=mc^2

Energy = Mass x Speed of Light squared

Energy = 2,887,240,000,000,000kg x (299,792,458m/s x 299,792,458m/s)

Energy = 2,887,240,000,000,000kg x 8.99×10^16m^2/s^2

Energy = 2.59×10^32 joules

            For a frame of reference that is just a bit more than the gravitational binding energy of the Earth, or the amount of energy that is holding the planet together.  It also happens to be just a bit less than the amount of energy released by the sun in one year.


            I’m really not surprised by just how ridiculous the numbers were, and I can’t really take it any further as it’s entering theoretical physics, and sparkly magical bullshit territory.  That being said I do have another Science of Fate post I am working on, namely Frankenstein, which is based on some interesting real-world science that I read about recently.

The post Just how much power does it take to form a Reality Marble? appeared first on Anime Science 101.

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Anime Science 101 by Chris Meharg - 3w ago

           Two weeks ago I flew out to Denver for the Colorado Anime Fest at the Denver Marriott Tech Center.  Thus, I had a chance to attend and present at a convention and see Denver at the same time.  The convention itself is not a large convention although they are growing with over 3,100 people attending.  Despite its small size compared to some of the conventions I normally attend like Katsucon and Otakon, it had some things that were quite surprising.


            I’ve never really been all that interested in the guests conventions bring in but I will say Colorado Anime Fest had more than I expected for a convention of its size.  It was 10 in case you are wondering, and included the English voice actors from a number of prominent shows like Laura Landa, who is the English voice of Sailor Neptune from Sailor Moon.

Anime Bar

            Yes, you read that correctly, Colorado Anime Fest had an anime bar, which is something I have yet to see at a convention.  They cordoned off a section of the hotel gallery next to the restaurant and carded people as they entered meaning everyone inside was over 21.  Yes, you had to get carded again when buying drinks (which included several alcoholic options), but I’ve never seen anything like it before at a con.  I know that Otakon has had the 18+ Jazz dance event in the past, on top of normal 18+ con programing, but never anything 21+.  While I did not partake of the alcoholic drinks, it was a fun way to meet, greet, and mingle with the older crowd at the convention without the younger kids.  Now don’t get me wrong, there is nothing wrong with the kiddies at the convention, especially this one where everyone was very well behaved in my opinion.  However, it is nice to have a space for just us adults at the convention as well.

            I got the chance to chat with a wide range of people from convention staff to congoers.  I even got an invitation to another Colorado anime convention in the fall, Dakucon, which I am considering if the dates line up for me.  It was also my first time playing Never Have I Ever, which is a weird but surprisingly fun game.  If I had one complaint, it was while playing Never Have I Ever, it was the rather inebriated individual next to me.  I don’t know if he was full blown drunk, but he was clearly rather intoxicated and loud, which was slightly annoying.  Secondly the music was a bit loud, but I’m more sensitive than most to that sort of thing.

Attended Panels

           I didn’t get a chance to attend a large number of panels at Colorado Anime Fest since I arrived on Friday night, and I was giving 7 panels of my own over 2 days.  That being said I did manage to see a few that were interesting.

            Sister Cities- There were 2 separate panels about Denver and its sister city Takayama.  This was interesting for me because while I have been to Takayama, I was curious about the idea of sister cities and how that works.  It was quite interesting and there are some unique opportunities for those living in Denver to explore Japan through the sister cities program.

            Crazy, Rich Culture: Japan and Asia in US pop culture- I tried to sit through this one, as I was curious about what the panel had to offer, and how much of it I might have seen while teaching in Asia.  Sadly, it was rambling and off topic, so I left early.

            Japanese Myth and Media- This panel was a surprise, because while it was similar to Charles Dunbar’s panels on the topic, it covered several myths that I have yet to learn about like the Ixion, and Baku.

            AMV wakeup- I’m always a sucker for good AMV’s and there were a number of them at the panel.  If I had to say which one was the best, I would say the one about The Ancient Magus’s Bride set to dialogue and song from Beauty and the Beast.

Presented Panels

            It was a whirlwind of panels this time, Anime Biology 101, Anime Chemistry 101, Anime Physics 101, Head Injuries in Anime- why shounen protagonists all have brain damage, The Terrible Chefs of Anime, Teaching with Anime, and Off the Beaten Track in Japan.  I was really surprised by the turnout given the small size of the con, but Anime Physics 101 was a full house.

           Everyone was great and not once did I get anyone trying to play stump the panelist, which normally happens at least once during Colorado Anime Fest.  You guys were a great crowd.


            Cosplay isn’t really my thing, but I can certainly appreciate good cosplay when I see it and there were several at the Colorado Anime Fest.

Fate Apocrypha- Frankenstein

Cells at Work- Red and White Blood Cell


            If you do take a few days to travel to Denver for the convention, I highly recommend you take some time to see the city.  Denver has a very vibrant and tasty food scene, with a number of food tours.  I did one and I would recommend it to anyone, as you can see the city and have good food at the same time.

The post Colorado Anime Fest 2019 appeared first on Anime Science 101.

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Anime Science 101 by Chris Meharg - 1M ago

            If you already know what I am talking about, great; if not, then you need to go watch Your Name immediately.  It is a great movie and you do not know what you are missing out on.  Kuchikamizake is a type of ceremonial sake that is only made at Shinto shrines and is probably closer to how sake was originally made than the more modern sake varieties.

Chewing Rice

            Kuchikamezake roughly translates to mouth chewed sake, and while sake is also called rice wine, it actually has much more in common with beer than wine.  However, like all types of alcoholic beverages it all comes back to yeast fermenting sugar and creating alcohol (ethanol) as a byproduct, which humanity loves to drink since 7000BC (China).

            If you know anything about food and biology, you will realize that this is a problem because the sugar in rice is starch.  Starch is a complex carbohydrate made up of long chains of simple sugars like glucose.

            Yeast can break down and process simple carbohydrates like glucose and turn it into alcohol, but it can not break down complex carbohydrates like starches.

            What you need to remember is that all of the sugar in rice is in the form of starch, which yeast cannot break down.  This of course begs the question of how is rice used to make sake when the yeast cannot ferment and turn starch into alcohol?  After the 8th century the answer would be the koji, or Aspergillus Oryzae, a mold that breaks down starch, releasing glucose that yeast can ferment.

            Before the 8th century, however, the solution was human spit or saliva, which does sound a little disgusting, but it served an important purpose.  Besides, the alcohol will probably kill anything anyway.  Human saliva contains the enzyme amylase, which breaks down starches into glucose.  (If you don’t believe me, chew a piece of bread for a long period of time and you will notice it becoming sweeter as you chew, as the amylase breaks down the starches in the bread.)  There are also bacteria in our mouths that can break down starches into simple sugars that yeast can ferment.  So by chewing the rice for a while and then spitting it out and letting it sit for a while one can prepare the rice for fermentation.  The priestess’s do not have to chew all of the rice, just a small portion which is then placed with the rest of the rice.  The bacteria then spread across all of the rice, breaking down the starch.

Kuchikamizake - Your Name (Kimi no na wa.)-kzTcvPI-IA4 - Dailymotion

            In fact, the use of saliva and the bacteria in it is one of, the first steps in making a variety of traditional alcoholic beverages around the world.  This includes airag, the national drink of Mongolia, which is basically fermented horse milk.  Airag is made by sitting a pot of horse milk by the door of the ger (traditional Mongolian house), and each time a person passes by, they spit into it.  This adds the bacteria needed to turn the complex sugars in horse milk into simple sugars, allowing the yeast in the air to ferment it.  (FYI- Not something I recommend trying as it is a very acquired taste.)

But Why does it have to be young Shinto Priestesses?

           The only remotely plausible scientific reason for kuchikamizake to be made by young female virgins is that the bacteria that live in and on every human being differ slightly between males and females, and as you age.  So it is possible that the bacteria that live in the mouths of young girls is different enough from older individuals and males to give the resulting sake a different taste.  Now I personally don’t put too much stock in this theory, but no one has done any actual research on it either.

           There could be some religious reasons for the use of young girls in the making of kuchikamezake, but I am a science teacher and not a religion teacher, so I can’t really say much about it.  Culturally, however, there is one potential reason for the use of young girls in the making of sake.  The indirect kiss is a thing in Japan and shows up in many anime.  Perhaps the making of Kuchikamizake is just a way for many people to have that indirect kiss with a nice looking young girl, possibly making it the original example of the trope.


            Normally sake is pressed at the end of the fermentation process to remove the remaining bits of rice that have not completely broken down, as well as other large pieces that are in the rice, water, saliva, bacteria, yeast, and alcohol mixture.  In Kuchikamezake this step is skipped, which adds to the sake’s unique appearance and flavor.


            After being pressed sake is also filtered and pasteurized, which is also left out in the production of Kuchikamizake.  The filtration process removes impurities to refine the taste and color of the sake, while pasteurization process kills the bacteria, mold, and yeast in the sake, meaning that it can be stored longer, as well as being safer to drink.  Both of these steps are skipped in the making of ceremonial sake like Kuchikamizake.  The resulting drink looks nothing like the clear sake we normally see.

            It’s more like a milkshake, or really thick soup, than a nice clear sake.  The white color and chunky texture is due to the non-fermented rice not being filtered out of the sake.  As to the flavor, well it is not as bad as you would expect.  It has a sweeter than expected flavor, and you can taste the alcohol, but it’s not a strong taste, there is also an undercurrent of floral notes.  It’s not bad, but not particularly good either, in my opinion, but if offered Kuchikamizake or airag, I will take the sake every time.

Finding Kuchikamizake

            Now if you are wondering how in the world I got the chance to try Kuchikamizake, a ceremonial sake only made at certain Shinto shrines, and only served during certain Shinto celebrations, let me explain (also known as story time to my students).  My chance came during my first trip to Japan in the spring of 2013, where I spent 8 weeks traveling the country as a reward to myself for completing my masters.  (I saved up for a long, long time to do this.)  During my grand adventure I made a stop in Shirakawa-go, which is best described as the Japanese version of Colonial Williamsburg.  It is a small rural village where most of the inhabitants still live in traditional buildings that are several hundred years old.

            As expected Shirakawa-go has a small Shinto shrine, which is not much compared to the massive shrines found in Tokyo, Kyoto, and Ise, but it is one of the shrines that is still allowed to make Kuchikamizake.  It also had had a Shinto celebration recently that involved Kuchikamizake.  Normally the shrines can only serve the Kuchikamizake during the celebration, but there is a loophole for all of the remaining sake.  The shrine is allowed to serve it to tourists visiting the shrine if they choose to, instead of letting the sake go to waste, as it cannot be stored for long periods of time.  I just so happened to be one of the few tourists in town that day, and was the only one at the shrine, and one of the shrine maidens offered to let me try some because I was a tourist and clearly not a follower of the Shinto religion.

            If you don’t have the opportunity or means to travel to Japan and be at the right shrine at just the right time, there is a way for you to get a taste of what Kuchikamizake is like.  There is a type of sake called Nigori-zake, which is an unfiltered sake much like Kuchikamizake, and it can be bought outside of Japan.

Drinking KuchiKamizake in Your Name

            During the climax of Your Name Taki finds the Kuchikamezake and decides to drink it in hopes of reaching her.  Now there are a couple of things you need to know about Kuchikamizake: it is not pasteurized, so its shelf life will be limited, especially in an unsealed, unrefrigerated container sitting at a small Shinto shrine in a cave.  Normal modern filtered and pasteurized sake is only aged for 6 months and is good for 6 months after that.  I can only imagine what is happening inside of the container during the three years that it sat in the shrine before Taki finds it.

            This is what the sake looks like after Taki shines his light on it, and it’s clear that there are what looks like bits of rice in the saki, but it should have a whiter cloudier color for kuchikamizake.  Then he actually drinks it and has an experience.

           Mystical plot elements, aside I think anyone would have a moment after drinking 3 year old unfiltered, unpasteurized kuchikamezake.  Sake has some similarities to wine, and wine will turn into vinegar over time when exposed to air, which would be the case in an unsealed container.

            For the more chemically minded here is the equation.

           I can only image the horror he is subjecting his taste buds to as the kuchikamezake is probably more vinegar than sake at this point, plus all of the other microorganisms and chemicals in the sake.


            I hope you guys enjoyed this mix of science and cultural content which is a little outside the norm of what I normally do hear at Anime Science 101.

The post Kuchikamizake appeared first on Anime Science 101.

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Anime Science 101 by Chris Meharg - 1M ago

K            Katsucon is one of my must attend cons and I was worried I would miss it this year, as I am now working on the west coast.  Thankfully my schedule lined up with the convention and I was able to attend.  I did have to take to the red eye from the west coast arriving Saturday morning, and was running on sugar and caffeine (café mocha is a godsend).  That didn’t stop me from presenting two panels, though.

The Biology of My Hero Academia- What the heck is a quirk and how does it work?

Gravity in Anime- Why too much or too little of it could kill you

            Again, thank you to everyone who attended my panels and I hope you had as much fun attending them as I did presenting them.

            I missed Friday and had to leave early Sunday morning so I only really attended the con on Saturday and the only event I was interested in attending was the Saturday Morning AMVs, which were amazing.  My favorites included the TV spots, which had Macross set to the original Battlestar Galactica, and Miss Kobyashi’s Dragon Maid set to Godzilla 2014 (which was the winner of the TV category).  They had me and everyone else in stiches.  The K-On one set to Queen was alright, but I will admit some it was lost on me as I’m not a Freddie Mercury fan.

            I was a little disappointed in the dealers room because while I did find what I was looking for, I couldn’t find it at a good deal.  I was hoping to pick up more of the Spice and Wolf manga, and the Arpeggio of the Blue Steel manga, but I could only find them at market price.  If I have to pay full price, then I’ll just order them online and avoid shipping them back.  The Star Wars display in the back was nice, though.

            My final stop was the artist alley, which is always fun seeing what people come up with, especially my favorite artist, muddymelly.  This time I only picked up some post card sized pieces, but they were excellent as always.

            While my time at the convention was short, a fun time was had by all.  Oh, and I did manage to snag a nice picture of the Sierra Nevada mountains on the way back.

The post Katsucon 2019 appeared first on Anime Science 101.

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The Promised Neverland– Demon Evolution

SPOILER WARNING for the latest chapters of the Manga

In chapter 120 of TPN we are finally given some insight into the origins of the demons and their need to eat humans to survive.  There were a couple of different ways that the manga could have gone with this and I was intrigued that they used a more scientific approach discussing evolution via vertical and horizontal gene transfer.

Vertical Gene Transfer

Evolution, as I have covered before, is how an organism slowly changes over time as it acquires traits that help it better survive in its environment.  The new traits arise from random mutations and any new trait that helps the organism survive and reproduce is going to become more frequent in the population as organisms with that trait have more offspring that also have the trait.  For example, when a new mutation grants an insect resistance to a pesticide, the insects that have resistance increase in number while the ones that don’t die off.  This continues until almost all of the insects are resistant to that particular pesticide, as was the case with flies and DDT.  Now what I just described is actually vertical gene transfer or the passing of genetic traits from parent to offspring.

FYI- vertical gene transfer is not usually used to refer to this process as it is normally referred to as evolution or natural selection.

Horizontal Gene Transfer

Horizontal gene transfer, on the other hand, works a bit differently and instead of passing genetic material from parent to offspring, the genetic material is passed to another individual in the same generation.  Additionally, the information is being passed between organisms that are different species.  It most common in bacteria and happens via the transfer of plasmids, which I discussed in my post on the quirks of My Hero Academia.  To recap, plasmids are extra chromosomal segments of DNA that can be transferred between bacteria and some single celled organisms like yeast.

The plasmids are not necessary for the bacteria to survive, but they often grant additional traits like antibiotic resistance.  The plasmids can be transferred from one organism to another via a process called conjugation.  In conjugation the plasmid reproduces and is then transferred to another bacteria via an extension of the cell called a pilus.

Now by this point you are probably thinking this is all nice and good but the demons of The Promised Neverland evolved by eating other animals and absorbing their genes and not by reproducing or sharing plasmids with them.  As it turns out, bacteria can absorb plasmids and genetic material from the environment around them, as was discovered by the transformation experiments of Fredrick Griffith that showed that you could turn a harmless bacterium into a pathogenic one via the remains of dead pathogenic bacteria.

Oswald Avery expanded on Griffith’s research on transformation proving that it was DNA passing between the dead and live bacteria that was causing the transformation.  This of course fits with the demon’s evolving through absorbing the DNA of other organisms.  However, by this point I think we can also assume that demons are eukaryotic organisms, given that they for all intents and purposes appear to be large complex multicellular organisms.  So how does gene transfer work in eukaryotic organisms?

Endosymbiotic Theory

If we go by what Norman says in the manga that the demons might have started as bacteria, the first step in their evolution via horizontal gene transfer would be by absorbing plasmids of other bacteria.  But bacteria are small single celled organisms that do not form large complex organisms like the current demons we see in the manga.  So how did they become the demons we see in the manga?

As it turns out, horizontal gene transfer played a role in the evolution of eukaryotic cells in the real world.  If you know anything about eukaryotic cells, you know that the DNA is contained inside the nucleus and the cell contains structures called organelles.  Organelles can be thought of as miniature organs that perform a particular function for a cell like our own organs do for our bodies.  There are a number of organelles, but there are only 2 that concern us today and they are the mitochondria and the chloroplast.  This is because they both contain their own DNA and replicate separately from the rest of the cell.  These two organelles are proof of something called endosymbiotic theory.

In a simplified form endosymbiotic theory is the theory that eukaryotic cells arose when a large bacterium ate another smaller bacterium, and instead of digesting it let it live inside of itself.  The smaller cell now lived on inside of the larger one granting it new traits like the ability to perform photosynthesis (chloroplast) or more efficiently breakdown sugar (mitochondria).

It also fits nicely with Norman’s explanation of demon evolution via eating other organisms.  However, their evolution didn’t stop there, as horizontal gene transfer allowed them to continue to evolve.

Horizontal Gene Transfer in Multicellular Organisms

Now this is were we get to some very new and interesting aspects of biology.  Studies have shown that horizontal gene transfer has happened between various organisms such as:

Bacteria to fungi, plants, and animals

Insects to fungus and round worms

Human to protozoan

Scientists know that these transfers have occurred but the how and why has yet to be determined; it is suspected that DNA transposons are involved.  Transposons are segments of DNA that do not like to stay where they are in an organism’s genome and have a tendency to jump around.  Think of it like a page in a book that keeps jumping around the book.  Lastly, all of this transferring is thought to play a role in the evolution of numerous species, but it is only just now being investigated.  In fact, up to 3% of the human genome could be made of transposons.  So modern science does still match up with Norman’s explanation of horizontal gene transfer playing a role in the evolution of demons.

Development of Language and Culture

Now this is where Norman’s explanation starts to go off the rails a bit, as I read that last part stating the demons developed language and culture as a direct result of eating humans and not as a result of their improved mental capacities via gene transfer.  It is as if they gained the knowledge as a direct result of eating humans.  FYI- while we are on the subject, what about the other intelligent animal species like gorillas or dolphins, as they too would have influenced the demon’s intelligence and development?

By this point you are all probably saying well, duh, you can’t absorb another organism’s knowledge by eating it……

Well, this is where it gets interesting.  In the 1950’s and 60’s a scientist by the name of Dr. James V. McConnell was investigating memory using flatworms.

His experiment was rather simple, in that he would train a flatworm to go through a maze and then cut up the worm into tiny pieces feeding it to other non-trained flatworms.  The non-trained flatworms would then be able to go through the maze like a trained worm.  Does this mean the demons of The Promised Neverland are really just mutated flatworms?

No, because scientists could never reproduce the study, and the original study was shown to have a number of flaws.  FYI- Some more recent studies have shown that flatworms do have some interesting quirks when it comes to memory.  First off, let me inform you that flatworms have an amazing ability to regenerate and that includes having their head cut off.  In this case trained flatworms had their heads removed and yet still remembered the training even after the brain was completely regrown.  Whether this means that their body has some other way of retaining memory outside the brain or that the study was flawed in some way is still open to debate.

That’s not how it works

Honestly, I don’t know what else to say to this part other than that’s not how biology and genetics works.  You can’t lose a genetic trait once you have it, even if it is a plasmid.  According to Norman the demons will lose their human intelligence, becoming wild, after not eating humans for 6 months.

Oh, and an organism whose genetic code can change that much would have a lot of problems with cancer and other cell growth disorders.  FYI- yes, I know that some viruses can mutate very quickly, but viruses are not considered to be living things, as they lack cells, among other things.

Plot Point

Now if you were like me when you read chapter 120 you were thinking, wait a minute, something doesn’t add up.  Well it looks like Emma and Ray thought the same thing too as of chapter 123.

They also come up with several explanations as to why Sung-joo and Musica are able to retain human form and intelligence without eating humans.  We will have to wait until their talk with Norman to find out the answer to that question.


The Promised Neverland has been one of my favorites for a while now, with its mix of action, adventure, and mystery.  The latest chapters have been no different and it’s refreshing to see a manga use new discoveries in science as part of the plot.  I do realize that it does get some things wrong, but I’d like to think I wasn’t the only one who went to go look up more about the topic.  As much as I liked the use of biology in chapter 120 of The Promised Neverland, I am going to have to call it busted.

For now, anyway, because it looks like there is still more to be revealed about the biology of demons.  This is because of the way they seemed to gain knowledge and intelligence.  The manga also downplays standard evolution a bit too much for my liking.  Then there is the matter of the fact that the demons will revert to wild animals after not eating humans for 6 months, which I do realize is questionable right now, so I will revisit the topic in the future as the manga reveals more information.

The post The Promised Neverland- Demon Evolution appeared first on Anime Science 101.

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Anime Science 101 by Chris Meharg - 3M ago
Adventures in Japan

Adeventures in Japan is going to be different from what you usually see from me as there will be no science involved, and I will be primarily talking about travel, specifically traveling in Japan, which is the mecca for anime fans around the world.  As I’ve mentioned on the course syllabus page, I have been to Japan twice for a total of almost 9 weeks.  Two months is a long time in any country, and I saw much of the country, including some areas that are a little off the beaten path for an American tourist.  Also, for those of you who know me, you know how my trips tend to end up, and for those of you who don’t well, I tend to have the bad luck or good luck, depending on who asks, of always having the most interesting adventures when I travel.  As such there is far too much to pack into one or even a few blog posts, so I wrote a book about my travels that you can find on Amazon.

Adventures in Japan is part travel guide and part travel diary so you can learn what to see and do in Japan, and what not to see and do in Japan, based on my own experiences.  I’ll give you tips on where to stay, like ryokans, which are the Japanese version of a bed and breakfast which are usually the same price or less than hotels, and include some meals.  Then there are the interesting tours like kayaking the canals of Tokyo.  Yes, Tokyo has canals and at one point they had more canals than Venice.

Don’t worry it’s not all about Tokyo as I made it to 33 cities on Honshu, Shikoku, Kyushu, Hokkaido, and the Ryuku islands.


Kushiro- Not much to see but a nice starting off point.

Lake Akan- Yes, Japan still has some bears, but the scenery is beautiful.

Abashiri- Make sure you go to the prison museum and not the actual prison.

Asashikawa- Sake brewery tours.

Sapporo- There is a lot to see and the people are very friendly.  You might just be asked to join a party when at an izakiya for dinner.

Otoru- A quaint little town with some interesting history from the Meji period.

Noboribetsu- lots of hot springs and skip the Ninja village

Hakodate- The fish markets are like aquariums, but you’re allowed to take them home and eat them.


Hakone- A must see for EVA fans, and history buffs for the remains of the Tokaido.  Plus, the hot springs are great.

Takayama- a quaint little town in the alps with great local sake

Shirakawa- It’s like Japanese colonial Williamsburg and it was one of my best nights in Japan.

Kanazawa- It has Samurai, Geisha, and temple districts plus an enormous castle.  If you are a fan of Ruroni Kenshin, it is worth the trip.

Nagoya- It has one of the three big Shinto shrines in Japan.

Ise- The Shinto Vatican of Japan.

Nara- The Buddhist Vatican of Japan, with friendly deer, and don’t be surprised by school students looking to talk English with westerners.

Kyoto- It is packed with history and you can see the sites from the Negima manga.

Mt. Koya– It has some interesting vegan cuisine and I recommend bringing snacks.

Osaka- One of the better castles with some interesting history, and, well, let’s just say getting to the aquarium was an adventure.

Himeji- The castle and the garden are great, but make sure to hear the story of Okiku’s well.

Hiroshima- A sobering experience, but it has really good Sukiyaki.

Miyjima- one of the three scenic spots of Japan and the deer are jerks.

Hirosaki- Not much besides an old castle and the Japanese hornet or, as I like to call them, sausages with wings.

Kakunodate- this is a gem of a town with several museums for anyone interested in Samurai history or the Edo period.

Sendai- Not much to see, but I did run into a principal of an international school.

Matsushima- another one of the three scenic spots of Japan

Nikko- Famous for its Buddhist temples and burial grounds.


Nagasaki- Ghost in the Shell fans should go and see the real Dejima.

Kagoshima- A must for Saigo Takamori fans, and there is a volcano in the bay you can hike on.


Matsuyama- A nice jumping off point for the Shimanami Kaido, and if you go to see the castle, take the rope way it’s a lot easier that way.  Oh, and it has the famous Dogo onsen.

Ryuku Islands

Okinawa- there is a lot to see, and the island is bigger than you think.  Scuba diving or snorkeling is a must.

Ishigaki- the barbeque is to die for

Iriomote- I wanted to see the wild cat but kayaking in the jungle was just as good, just watch out for tropical storms.

Consider this just a teaser of what to expect if you decide to check out my Adventures in Japan currently available Amazon.  So, come along with me on  Adventures in Japan.


The post Adventures in Japan appeared first on Anime Science 101.

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Helix Waltz

As you know from my post about poisonous mushrooms and their use in Recettear, I have been trying to expand and look at some of the science topics portrayed in video games.  Helix Waltz is a dress-up drama mobile game made by Crossing Star Studio.  In the game you play as Magda, who is an orphan girl adopted by a fallen noble family raising her in the hopes of restoring the family to power.  Madga meets numerous people and attends a variety of events and the results are based mostly on the clothing she is wearing at the time.  Now this might not seem like a place for anime science, but there is always a bit of science to be discussed.  In this case I will be looking into the science of shoes and how they affect the body.

The Game

Very early on in Helix Waltz the heroine Magda complains about her feet hurting.

You then discover that she has been wearing footwear with elevated heels all day, and this is where the science begins, but before that a little history.

Warning: History Lesson

Heeled shoes date all the way back to the tenth century and were used by archers on horseback, as the heel provided extra stability when riding and shooting.  I can imagine how helpful this would be as my feet were constantly falling out of the stirrups when I went horseback riding in Mongolia.

Heeled footwear was also used during the medieval ages as a way to keep your feet out of the dirt and muck that littered the streets of cities during that time period.  In one case the city of Venice passed regulations limiting the height to three inches.

Chopines (High Heels)

The modern heel didn’t appear until the 1700’s when they were worn by both women and men.  They were used as a status symbol to raise your height above that of a lower class individual.

While it is not stated in Helix Waltz, I believe the game is set in a fictional European setting around the 1800’s.

History Content Over Effects of Heeled Shoes

Leaving all other things aside, wearing shoes with elevated heels has a number of effects on the body as Magda learned firsthand.  When standing barefoot, the bulk of the body’s weight is directed on the heel.  This changes to a 50/50 split when wearing a regular shoe, which elevates the heel slightly, as seen below.

This changes again when wearing a shoe with an elevated heel.  The body weight is shifted forward, putting more pressure on the toes.  The degree to which the weight is shifted is determined by the height.

It is this shifting of the weight distribution on the foot that causes many of the health issues related to heels.


With the body’s weight shifted onto the toes, it forces the toes forward, pressing them against the front of the shoe, and out of alignment.  Over time this can lead to bunions, which are bony bumps at the joint of your big toe, which can be quite painful.

Magda has not been wearing the shoes long enough to develop bunions, so I believe that her pain is coming more from her toes being pinched in her shoes rather than bunions.

Plantar Fascia

There are a variety of structures helping to hold our body together, such as muscle and bone.  Another structure that is equally important, but not as widely known outside of medical/biological circles, are fascia.  Fascia are a type of connective tissue, (tissue that holds the body together) that attaches muscle to bone and keeps muscle separate from other body structures.  Now despite the name the Plantar Fascia is not Fascia, but another type of connective tissue called aponeurosis, which for simplicity’s sake acts like a tendon and connects muscle to the body part it moves.  In the case of the Plantar Fascia it connects the Achilles tendon to the bottom of the foot via the heel bone.

In addition to connecting the Achilles tendon to the bottom of the foot, it plays a major part in the structure in the arch of the foot, and how people walk.  I also found a study that found the plantar fascia bears over 10% of the body’s weight when standing and walking.  It should come as no surprise that a person’s choice of shoes can impact their plantar fascia.

Shoes with an elevated heel change the position of the foot, which changes the shape of the foot, and the plantar fascia along with it.  Over time this can cause the plantar fascia to become inflamed, which is known as plantar fasciitis.  Elevated heels also tend to lack padding underneath the heel which can exacerbate plantar fasciitis.

It can take some time for plantar fasciitis to develop so I am reasonably certain that it is not the source of Magda’s foot pain at the current time, but it could become a significant problem for her in the future.


Have you ever had that tingling sensation in your arm after you laid on it for a long period of time?  If you have, you probably said that your arm fell asleep.  This happened because you compressed (pinched) a nerve for a long period of time.  In the case of an arm or a leg falling asleep the pinched nerve results in some annoying tingling for a short period of time.  However, if other nerves in the body are compressed, the results can be quite painful such as a pinched nerve in the back.

The shoes you wear can also cause you to pinch a nerve in your foot.  This depends on the type and style of shoe that a person decides to wear, and elevated heels can be particularly troublesome in this regard due to how it changes the position and shape of the foot.  While I have never worn heels, I have experienced foot pain from compressed nerves before, while rowing in college.  Stuffing my size 13 foot into shoes more than a few sizes too small left me in more than a bit of pain by the end of practice.  Of everything I have discussed thus far, I think that a pinched nerve due to elevated heels is the main contributor to Magda’s pain.  This is supported in the game by a nice line from Magda’s mother.


I do realize that I left out a number of complications of high heels; however, it is fairly clear that Magda is wearing heels for the first time when the game begins.

Thus, I did not go into some of the common long-term problems caused from wearing shoes with elevated heels.  Out of the conditions I mentioned, I feel that a pinched nerve and altered shape of her foot are the cause of the pain that she is in by the end of the ball.  So I am going to call this aspect of Helix Waltz confirmed.

I will say that I was pleasantly surprised to find this particular aspect of fashion and biology played straight, considering how many anime and video game heroines pull off feats in footwear that would be impossible in the real world.

FYI– In the spirit of full disclosure I made this post after being approached by New Code about creating a post about Helix Waltz and this is the result.

The post Footwear in Video Games- Helix Waltz appeared first on Anime Science 101.

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Spider Size vs Venom Toxicity

I am firmly convinced that Okina Baba is a big fan of spiders, or at least has more than a passing knowledge about them.  This is due to the number of spider references in “So I’m a spider, So what?”.  Many of Kumoko’s spider attacks are based on the abilities of a variety of real-world spiders, some of which aren’t the most common, spiders either.  Now in the world Kumoko finds herself, one can level up or change into different versions of themselves.  In Kumoko’s case it’s other types of spiders found in the world she is currently living in.

This brings up another aspect of spiders, which is the common notion that the larger the spider, the less dangerous its venom.  FYI- I will be looking at how dangerous it is to people.

Venom vs. Poison

A venom is a toxin that is injected into the target.  This usually happens via fangs or a stinger of some sort.

A poison is a toxin that is ingested by eating an organism that contains a toxin.  An example would be a puffer fish, which can be dangerous when eaten.

Do all spiders have venom?

The short answer is yes, virtually all of the 35,000 species of spiders have some sort of venom.  That being said, not all of them are dangerous to humans.

What happens during a spider bite?

The first step is fairly obvious, the spider has to actually bite you.  The next step is that the venom needs to be injected into the body, or envenomation.  Two things have to happen for this to occur: first, the fangs need to be able to penetrate your skin.  While this is not an issue for most spiders, it is a problem for other venomous organisms.

The next step is that the spider must inject the venom into the organism that is has just bitten.  This is a given in spiders, but there are sme organisms that do not inject venom with every bite, namely some snakes.  When it comes to the venom itself, there are two things that matter, the amount and the type of venom that is injected into the bite.  Fun fact: contrary to popular belief tarantulas do not have large venom glands or inject a lot of venom into the organisms they bite.  I can also say from personal experience that tarantula bites are not dangerous, but they do hurt because their fangs are quite large.

Types of Venom

Unlike spider silk, each spider or group of spiders will use different toxins in their venom, and each spider only makes one kind of venom.  In broad strokes, there are 2 types of toxins found in spider venom.

Cytotoxin/Necrotoxins– These toxins cause the death of cells in the area around the bite.  This type of toxin is used by brown recluse spiders.

Neurotoxins– These toxins directly influence the nervous system and tend to be faster acting than other types of toxins.  They are used by black widow spiders.

Don’t forget that you also have to consider the amount of spider venom that is injected with each bite, which varies with spider size.

Spider size vs. Venom toxicity

Does the size of the spider have anything to do with how toxic the spider is?  The short answer is yes, there is a general trend in spider size vs. how toxic the spider venom is.  I took the body length of the 9 most venomous spiders according to Encyclopedia Britannica, and compared it to the body length of the 10 largest spiders according to the Conservation Institute.

Average body size of the most poisonous spiders according to encyclopedia Britannica

Brown recluse spider 13mm

Brazilian wandering spider 32.5mm

Yellow sac spider 7.5mm

Wolf spiders 22.5mm

Black widow spiders 6.5mm

Brown widow spiders 12.7mm

Red widow spider 12.7mm

Red back spider 6.5mm

Funnel web spider 30mm

Average of all the spiders on the list- 15.9mm

Body size of the largest spiders in the world according to the conservation institute

Huntsman spider 22.5mm

Brazilian wandering spider 32.5mm

Camel spider 60mm

Hercules baboon spider- 100mm

Colombian Giant Black Tarantula- 90mm

Brazilian giant tawny red tarantula- 100+mm

Poecilotheria rajaei- 102mm

Brazilian Salmon Pink Birdeater- 100+mm

Huntsman spider- 25mm

Goliath Bird-Eating Tarantula- 119mm

Average of all the spiders on the list- 75.1mm

As you can see, the average body size of the venomous spiders is 15.9mm which is 21% of the size of the largest spiders at 75.1mm.  So yes, the smaller the spider the more dangerous the spider venom is likely to be.  Also, as I tell my students, there is an exception to every rule in biology and the Brazilian wandering spider, which is one of the largest spiders in the world, also has an extremely dangerous venom.  What is the reason for this trend you might ask?  The answer to that is fairly straightforward.  The larger the spider, the more strength it has to overpower its prey and/or opponents.  The smaller spiders need the spider venom to make up for the difference in size and strength.  For Kumoko the choice was obvious and she goes with the smaller more poisonous spider.


The idea that smaller spiders are more venomous as presented in So I’m a spider, So What is actually backed up by some real-world science, so I will be calling this one plausible, as there are some real-world spiders that break the trend.



Just in case you were wondering Kumoko is supposed to be about the size of a piglet, which is far larger than any spider ever found in the real world.

However, it makes sense in context as her “mother” is an enormous spider.

Second Bonus

Further along in the story Kumoko evolves into a spider with sharp sickles on the ends of her forelegs.

As crazy as it sounds, there is a real-world spider called the Trogloraptor that was discovered in a cave in Oregon that has sickles on its forelegs.

The post So I’m a Spider, So What?- Spider size vs venom toxicity appeared first on Anime Science 101.

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So I’m a Spider, So What?- Spider Silk

So I’m a Spider, So What? is an isekai light novel series by Okina Baba that will be getting an anime in 2019.  Now I haven’t read the light novel, but I have read the manga adaptation and to be honest, it really doesn’t do anything ground-breaking or exciting for the most part.  Fans of the genre or RPG style game might enjoy it more than I did.  The reason I am discussing this rather average isekai light novel is due to the main character’s being reincarnated not as a human, but as a spider.  This in and of itself isn’t new, as we have shows like That time I was reincarnated as a Slime, but what is new and different for me is the way it handles the spider abilities of the main character.

Spider Silk

Initially, our main character, Kumoko, who is now a spider, is fairly limited in her skill set, having just her spider silk and fangs.  However, as most people know, spider silk is actually surprisingly strong, and is considered stronger than steel, which is correct, but I want to dive into it a bit here.  When discussing how strong spider silk is, there are two terms that we need to know, strength and toughness.  Strength, in this case tensile strength, is the maximum load (weight) a substance can handle before breaking.  In this regard spider silk is indeed stronger than steel, when comparing two strands of equal length and diameter.  Kevlar, a synthetic fiber used to make bullet proof vests, is stronger than spider silk, but it is not as tough.

Toughness in material science refers to how much energy a material can absorb before breaking.  Think of it like a rubber band, how far can you stretch the rubber band before it breaks?  So, while Kevlar is stronger than spider silk, it is not as tough.  So while it can hold more weight, it cannot absorb as much energy.  This is highlighted in the graph below.

In other words, a given length of spider silk can be compressed down to 50% of its starting unaltered length, and pulled out to 5 times its unstretched length.  This gives spider silk a wide range of abilities.

But what is it made of?

Spider silk is actually a protein fiber and is actually quite complex.  It also shares some similarities to keratin and collagen, the proteins that make up nails and ligaments, respectively.  On a chemical level spider silk is made up primarily of the amino acids glycine (42%) and alanine (25%).

Other compounds are also added to the silk to alter its properties, like pyrrolidine, which helps the silk retain water, keeping it moist.  Potassium nitrate is added to prevent the spider silk from breaking down after it is made slightly acidic, to resist bacteria and fungus.

How is spider silk made?

Spider silk is made in the silk glands where it exists as a gel-like substance, and does not become silk until it is spun, which is a bit of a misnomer.  This is because spider silk isn’t spun, but rather it is pulled from the gland through a narrow opening, which creates the fiber we know as spider silk.

In this image you can see how the properties of the spider silk change (pH) as it is pulled out of the gland, with different materials being added in different sections.

Are there types of spider silk?

Your answer to this question is probably yes, because there are 35,000 different species of spiders, so logically it stands to reason that there are different types of spider silk.  And you would be correct- there are seven types of spider silk, each made in a different silk gland.

Major Ampulate- Dragline– strongest type of silk Flagelliform- Viscid- sticky strings of spider silk Aggregate- Glue like– sticky globs of silk Minor Ampulate- Minor– temporary web construction Cylindrical- Cocoon- reproduction Aciniform- Wrapping- used to secure prey Piriform- Attachment- part of web formation

Not every spider has every type of spider silk, but they all have at least three different glands for 3 different types of silk.  The question is, then, how many different types of silk does Kumoko have?

Kumoko’s silk

Over the course of the story we see Kumoko specifically reference using several different types of silk: elastic, sticky, poisonous, and sharp threads.  In addition to this we see her use silk in ways that can help us determine the total number of silk types she can make.

A web made by Kumoko

Her web looks like a typical spider web made by an orb weaving spider, and she made it using dragline silk for the thicker lines which support the structure of the web.  The thinner lines building out the rest of web are made using viscid silk.  These are the same types of silk she used to make her elaborate web bridge to fight wasps.

I also think she probably used attachment silk to make the floor of her bridge.  Another interesting attack used by Kumoko is basically a bolo covered in sticky globs of aggregate or glue-like silk.

Interestingly enough, there is a spider known as the Bolas spider that hunts using a sticky glob of spider silk at the end of a tether just like what Kumoko does.

The dance of bolas spider with its prey - YouTube

The final type of spider silk that Kumoko is seen using is aciniform, or wrapping thread.  Aciniform silk is used to wrap up prey, and Kumoko uses it as part of a trap seen below, in addition to its real world uses.

There is a group of spiders (Uloboridae) that use aciniform silk to trap, immobilize, and kill their prey, all without using venom.

Orb-Weaver Spider VS Huge Wasp | The Fastest Wrapping Up i Have Ever Seen - YouTube


Thus, I think it’s safe to say that Kumoko can use every type of spider silk except cylindrical spider silk, which is used exclusively for reproduction.

Bonus- Real world versions of Kumoko’s skills

There are a number of other skills Kumoko comes up with and uses that are actually used by real world spiders.  Some spiders will place strands of silk around their homes to protect it from ants, which Kumoko also does.

Some spiders will even use this trick to fish.

Poisonous spider silk

No, I am not making this up, but there is a group of spiders, the Scytodidae, known as spitting spiders, that can fire off venom-covered strands of silk.

Spitting spider nat geo special - YouTube

Spider net

It is a bit exaggerated here, but, yes, there is a spider that casts nets to catch its prey.  The Deinopidae, or net casting spiders, create a net out of spider silk and use it to hunt.

The Net Casting Spider. Deinopis cornigera. - YouTube

In this case it seems that the truth is indeed as strange as fiction.

Second Bonus

I would be extremely remiss if I did not mention one other aspect of spider silk, and that is that spider silk has very high nutrient and energy requirements.  Spider silk is very taxing for a spider to produce metabolically speaking.  Spiders can eat 12 to 32 times their body weight over the course of a year.  As a result, some spiders will eat their own spider webs to reduce the nutrient and energy costs of creating the web.  This would go a long way to explaining why Kumoko is such a glutton, or at least give her an excuse for her gluttony.

The post So I’m a Spider, So What?- Kumoko and spider silk appeared first on Anime Science 101.

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