Cockroaches, Alligators & Other Weird Sources of New Drugs

Cockroaches, Alligators & Other Weird Sources of New Drugs


Antibiotics are one of humankind’s most amazing
discoveries. Ever since that fateful day in 1928 when Scottish physician Alexander Fleming
noticed a funny mold growing in one of his petri dishes, antibiotics have been kicking
bacterial butt. That famous mold, of course, was producing
penicillin, the founding antibiotic superstar, which has since extended the average human
life by at least a decade. It fundamentally changed the face of medicine. Antibiotics,
or antimicrobials, are basically selective poisons designed to either kill or slow the
growth of bacteria to the point where your body’s own immune system can clean up. These
drugs target a specific part of bacteria or some important stage in their development
without damaging the body’s host cells. And they’re really great their job. Until they
aren’t. Lately, antibiotic technology has been having
a hard time keeping pace with bacterial evolution. We’ve talked here on SciShow about how lots
of your die-hard, go-to favorite antibiotics are starting to lose their mojo in the face
of sneaky and rapidly evolving bacteria. The US Centers for Disease Control and Prevention
estimates that at least 2,000,000 Americans became infected with drug-resistant bacteria
in 2012, and 23,000 of them died as a result. These superbugs are deadly serious and could
quickly unleash a global health crisis if we don’t find a way to keep them in check.
The problem is we’ve already hit up many of the most obvious sources of antibiotics, like
fungi, which includes penicillin, and synthetic molecules.
Fortunately, we humans have big, delicious brains, and some of the best of them are hard
at work trying to invent all-new ways to kill dangerous bacteria or find other organisms
on the planet that are better at it than we are so we can steal their secrets. And while
they’re finding some promising leads, I gotta say, they’re looking in some pretty weird
places. [Intro] You know how everyone jokes that after some
big global disaster, only cockroaches will survive? Well, we recently found what may
partially explain their famous, and infuriating, tenacity. Research from the University of
Nottingham suggests that certain insects, like roaches and locusts, have brain tissues
that are infused with super-powered antibiotic juju. The researchers found nine different
antibiotic molecules tucked into the roaches’ nervous systems that may be protecting them
from otherwise lethal bacteria. They’re all a type of molecule known as peptides, short
chains of amino acids that make up proteins, kinda like proto-proteins. And these peptides
are specific to the bugs’ brains. They seem to be chemicals that roaches” brain cells
use to communicate with each other, y’know, whenever a cockroach is sitting around thinking
about stuff, which I guess can happen, and although we’re not sure how these peptides
actually work, laboratory tests have shown that they’re incredibly effective at eliminating
some of our least favorite bacteria, like the most dangerous strains of e.coli, which
cause gastrointestinal infections. And even MRSA, a super-resistant type of staphylococcus
bacterium that can cause unstoppable deadly infections in humans, particularly in hospitals.
In lab trials, these roach brain molecules killed over 90% of MRSA bacteria, without
harming any host cells. So I can guess what you’re thinking: shut
up and take my money! Well, hold on a sec, because we’re a bit away from having cockroach
brains on the pharmacy shelves. There’s still loads of technical hurdles to overcome, tests
to conduct, basic things we need to figure out, like how exactly these molecules work.
But roaches aren’t the only hardy animals out there. Alligators are some of the Earth’s
most rugged beasts. They essentially live in cesspool swamps teeming with bacteria and
fungus and other microbes, and more than that, they’re known brawlers. Put just a few territorial
800 pound toothy reptiles together in a dirty swamp, and you will no doubt come out with
some serious bite marks and bloody wounds, even missing limbs. But amazingly, what you
probably won’t find are any infections. This got some bayou scientists to thinkin’!
Dr. Mark Merchant, a biochemist at McNeese State University in Louisiana, helped conduct
a decade long study that investigated what makes alligators so unusually resistant to
bacterial and fungal infection. Turns out, it’s in their blood. An alligator’s
immune system is largely innate, meaning it can fight off harmful micro-organisms without
having any prior exposure to them. They just pop right out of their eggs ready to do battle.
We humans also have some innate immunity, provided by things like our skin and white
blood cells, but a big part of our immunities are adaptive, meaning we often develop a resistance
to specific diseases only after being exposed to them. Which of course is not ideal all
the time, but alligators get to skip this step. Researchers examining blood samples from American
alligators isolated their infection fighting white blood cells and then extracted the active
proteins working in those cells. And these two included a special class of peptides which
seemed to have a knack for weakening the membranes of bacteria, causing them to die. When pitted
against a wide range of bacteria including drug-resistant MRSA, these tough little peptides
proved to be effective killers. They also wiped out 6 of 8 strains of candida albicans,
a type of yeast infection that’s particularly troublesome for AIDS and transplant patients
with weakened immune systems. Such compounds may also be found in similar animals, like
crocodiles, Komodo dragons, and the skins of some frogs and toads. So far, lab trials
have shown that gator blood can kill at least 23 different strains of bacteria including
salmonella, e.coli, staph, and strep infections AND even a strain of HIV. For now, scientists
are working to find the exact chemical structures at work in four of these promising chemicals
and pinpoint which types are best at killing which microbes. One problem so far: high concentrations
of gator blood serum have already been found to be so powerful that they are toxic to human
cells. So other biologists are taking a different approach in the search for the next generation
of antibiotics. Rather than looking at other animals, they’re
exploring strange, new places, like cave soils and deep-sea sediments. Researchers have recently
discovered evidence of promising new fungi strains living way down in hundred million
year old nutrient-starved sediments in the Pacific Ocean. Everyone thought this was a
near-dead zone for life, too harsh and remote an environment for something like fungi to
survive in. Just a decade ago, the only living things known to inhabit such deep sediment
layers were single-celled bacteria and archaea, organisms known to flourish in extreme environments.
But while examining dredged up sediments from as deep as 127 meters into the sea floor,
scientists found fungi of at least eight different types, four of which they successfully cultured
in the lab. Some of the fungi even belonged to the genus Penicillium, which we have to
thank for the development of penicillin. Now, we’re not exactly sure how old these fungi
are, but they are definitely quite old and maybe, more importantly, they appear to have
been living in isolation for eons. If that’s the case, they may have evolved specific and
unusual defenses against bacteria, which, just like their penicillin kin in that famous
petri dish, could end up being a new and powerful source of antibiotics.
And there’s one more strategy that scientists are using, one that works in espionage as
well as in medicine. And that is seeing what the enemy is up to.
While exploring life in strange new places around the world, some biologists are looking
for bacteria that have never been exposed to our drugs, but still appear to be naturally
resistant to them. Wherever we find the most naturally resistant
bacteria, we might also find natural antibiotics that we never knew about.
And here, one of the most promising leads is again in one of the hardest-to-reach places:
New Mexico’s Lechuguilla cave, a place that was isolated from all human contact until
it was discovered in the 1980’s. One of the many fascinating things that scientists
have discovered here is that the cave bacteria seem to be resistant to everything.
Even though they’ve never been exposed to us or our drugs, all of the bacteria have
proven to be resistant to at least one major antibiotic, and many tend to fend off more
than a dozen of the most powerful antimicrobials we have. This suggests to scientists that
the bacteria have evolved to be this way because they live in an environment that’s rich in
naturally occurring antibiotics, ones that the germs we live with up here on the surface
have never encountered. Now we just have to find out what exactly
those compounds are. So look, I’m not going to lie to you: we have
a lot of work to do. While we might discover a new super-drug lurking
in a cave or under the sea or in a cockroach’s head, there’s a big difference between finding
a substance that cleans house in a petri dish and actually putting a new antibiotic in the
vein of a human patient. So the bummer is, as promising as some of
these bold new discoveries may be, none of them has yet yielded an actual marketable
drug. Still, there’s a long list of successful antibiotics
that we’ve managed to derive from strange sources, starting with Dr. Fleming’s rogue
fungus. So if we keep exploring strange new places
and studying how other animals deal with the problems we’re facing, we just might find
the next penicillin before the superbugs get the best of us. Thanks for watching this SciShow Infusion,
especially to our Subbable subscribers. To learn how you can support us in exploring
the world, just go to Subbable.com. And as always, if you want to keep getting smarter
with us, you can go to YouTube.com/SciShow and subscribe.

How a Bee Becomes Queen

How a Bee Becomes Queen


(INTRO TUNE) Honey bees have a harsh caste system. Of
the tens of thousands of bees found in a hive just about all of them are female
workers and they do pretty much everything from cleaning and building
the hive, to collecting pollen and nectar. Their lives are so intense that while a
worker can live from four to nine months during the winter, a worker bee born in
the busy summer season will only last about six weeks before dying of
exhaustion. It’s not a whole lot better for the 300 to 3000 male drones who
basically hang around waiting to mate with the Queen during the summer after
which they die or are kicked out of the hive and when fall comes, and they are of no
more use. Then there’s that Queen. There’s one per hive and she can live to be up to five years old laying up to 2,000 eggs in a day. And she
owes her entire existence to a bitter protein-rich secretion called royal
jelly. Given their long life and unique position, there’s rarely a need for a new
queen, but when one dies or leaves the hive along with a swarm, the colony needs
to find a replacement and fast. In both situations, a larval bee is chosen to
become the new queen. The science of how and why this happens
isn’t entirely settled but one thing is certain, royal jelly plays a large role. Worker bees produce royal jelly from a
gland in their heads called the hypopharynx and feed it to newly hatched
honeybee larva. The milky-yellowish substance is made of digested pollen and
either honey or nectar. Not only is a high in protein but royal jelly also has
a combination of vitamins especially vitamin B plus lipids, sugars, hormones
and, minerals including potassium, magnesium, calcium, and iron. This bee “super-food”
also contains acetylcholine a neurotransmitter also found in humans.
It’s what nerves use to tell muscles to start or stop movement and may also
contribute to learning. All those nutrients might explain why royal jelly is often
marketed as an expensive, dietary supplement cure-all even though studies
haven’t been able to prove that it does anything too significant for humans. We are after all, not bees. But for bees, it
does a lot and around day three of the royal jelly diet is where things get
interesting. Worker bees will choose a few of the
larvae and continue to feed them royal jelly while every other larva is switched
to a less nutrient intensive diet of honey pollen and water. As the future
Queens gorge the royal jelly triggers other
phases of development that workers don’t experience like the formation of ovaries
for laying eggs. If one Queen emerges first she will search for and destroy
any other Queens still developing in their wax cells and if multiple Queens
come out simultaneously they will fight to the death until only one Queen
remains. We don’t know exactly how the worker
bees decide which larvae get the royal treatment but for a long time we thought
it was random. That would make sense because basically worker bees and queen
bees are genetically identical. But there’s some evidence that the selection of a
queen might not actually be so random. A 2011 study found that
the larvae of future Queens have higher levels of proteins that increase some
metabolic activities, so there may indeed be a tiny genetic
difference in the two that plays a huge role. Scientists are also still trying to
figure out what it is about the royal jelly that lets it change a larva’s whole
life. For a while we thought it might be a hormone in the jelly or the way it
affected insulin signals in the larvae then another 2011 study zeroed in on a
protein called ROYALACTIN which when isolated and combined with other
nutrients can transform larvae into queens just like royal jelly. Once they emerge Queens continue eating
royal jelly their entire lives and given that the Queen lives a lot longer than
the thousands of relatives around her, it sounds like a reasonable dietary
choice for a royal bee to make. Thank you for watching this SciShow dose which was
brought to you by our patrons on Patreon, if you want to help support the show you
can go to patreon.com/scishow and if you want to keep getting smarter with us just go to youtube.com/scishow and
subscribe (OUTRO MUSIC)

Cockroaches, Alligators & Other Weird Sources of New Drugs


Antibiotics are one of humankind’s most amazing
discoveries. Ever since that fateful day in 1928 when Scottish physician Alexander Fleming
noticed a funny mold growing in one of his petri dishes, antibiotics have been kicking
bacterial butt. That famous mold, of course, was producing
penicillin, the founding antibiotic superstar, which has since extended the average human
life by at least a decade. It fundamentally changed the face of medicine. Antibiotics,
or antimicrobials, are basically selective poisons designed to either kill or slow the
growth of bacteria to the point where your body’s own immune system can clean up. These
drugs target a specific part of bacteria or some important stage in their development
without damaging the body’s host cells. And they’re really great their job. Until they
aren’t. Lately, antibiotic technology has been having
a hard time keeping pace with bacterial evolution. We’ve talked here on SciShow about how lots
of your die-hard, go-to favorite antibiotics are starting to lose their mojo in the face
of sneaky and rapidly evolving bacteria. The US Centers for Disease Control and Prevention
estimates that at least 2,000,000 Americans became infected with drug-resistant bacteria
in 2012, and 23,000 of them died as a result. These superbugs are deadly serious and could
quickly unleash a global health crisis if we don’t find a way to keep them in check.
The problem is we’ve already hit up many of the most obvious sources of antibiotics, like
fungi, which includes penicillin, and synthetic molecules.
Fortunately, we humans have big, delicious brains, and some of the best of them are hard
at work trying to invent all-new ways to kill dangerous bacteria or find other organisms
on the planet that are better at it than we are so we can steal their secrets. And while
they’re finding some promising leads, I gotta say, they’re looking in some pretty weird
places. [Intro] You know how everyone jokes that after some
big global disaster, only cockroaches will survive? Well, we recently found what may
partially explain their famous, and infuriating, tenacity. Research from the University of
Nottingham suggests that certain insects, like roaches and locusts, have brain tissues
that are infused with super-powered antibiotic juju. The researchers found nine different
antibiotic molecules tucked into the roaches’ nervous systems that may be protecting them
from otherwise lethal bacteria. They’re all a type of molecule known as peptides, short
chains of amino acids that make up proteins, kinda like proto-proteins. And these peptides
are specific to the bugs’ brains. They seem to be chemicals that roaches” brain cells
use to communicate with each other, y’know, whenever a cockroach is sitting around thinking
about stuff, which I guess can happen, and although we’re not sure how these peptides
actually work, laboratory tests have shown that they’re incredibly effective at eliminating
some of our least favorite bacteria, like the most dangerous strains of e.coli, which
cause gastrointestinal infections. And even MRSA, a super-resistant type of staphylococcus
bacterium that can cause unstoppable deadly infections in humans, particularly in hospitals.
In lab trials, these roach brain molecules killed over 90% of MRSA bacteria, without
harming any host cells. So I can guess what you’re thinking: shut
up and take my money! Well, hold on a sec, because we’re a bit away from having cockroach
brains on the pharmacy shelves. There’s still loads of technical hurdles to overcome, tests
to conduct, basic things we need to figure out, like how exactly these molecules work.
But roaches aren’t the only hardy animals out there. Alligators are some of the Earth’s
most rugged beasts. They essentially live in cesspool swamps teeming with bacteria and
fungus and other microbes, and more than that, they’re known brawlers. Put just a few territorial
800 pound toothy reptiles together in a dirty swamp, and you will no doubt come out with
some serious bite marks and bloody wounds, even missing limbs. But amazingly, what you
probably won’t find are any infections. This got some bayou scientists to thinkin’!
Dr. Mark Merchant, a biochemist at McNeese State University in Louisiana, helped conduct
a decade long study that investigated what makes alligators so unusually resistant to
bacterial and fungal infection. Turns out, it’s in their blood. An alligator’s
immune system is largely innate, meaning it can fight off harmful micro-organisms without
having any prior exposure to them. They just pop right out of their eggs ready to do battle.
We humans also have some innate immunity, provided by things like our skin and white
blood cells, but a big part of our immunities are adaptive, meaning we often develop a resistance
to specific diseases only after being exposed to them. Which of course is not ideal all
the time, but alligators get to skip this step. Researchers examining blood samples from American
alligators isolated their infection fighting white blood cells and then extracted the active
proteins working in those cells. And these two included a special class of peptides which
seemed to have a knack for weakening the membranes of bacteria, causing them to die. When pitted
against a wide range of bacteria including drug-resistant MRSA, these tough little peptides
proved to be effective killers. They also wiped out 6 of 8 strains of candida albicans,
a type of yeast infection that’s particularly troublesome for AIDS and transplant patients
with weakened immune systems. Such compounds may also be found in similar animals, like
crocodiles, Komodo dragons, and the skins of some frogs and toads. So far, lab trials
have shown that gator blood can kill at least 23 different strains of bacteria including
salmonella, e.coli, staph, and strep infections AND even a strain of HIV. For now, scientists
are working to find the exact chemical structures at work in four of these promising chemicals
and pinpoint which types are best at killing which microbes. One problem so far: high concentrations
of gator blood serum have already been found to be so powerful that they are toxic to human
cells. So other biologists are taking a different approach in the search for the next generation
of antibiotics. Rather than looking at other animals, they’re
exploring strange, new places, like cave soils and deep-sea sediments. Researchers have recently
discovered evidence of promising new fungi strains living way down in hundred million
year old nutrient-starved sediments in the Pacific Ocean. Everyone thought this was a
near-dead zone for life, too harsh and remote an environment for something like fungi to
survive in. Just a decade ago, the only living things known to inhabit such deep sediment
layers were single-celled bacteria and archaea, organisms known to flourish in extreme environments.
But while examining dredged up sediments from as deep as 127 meters into the sea floor,
scientists found fungi of at least eight different types, four of which they successfully cultured
in the lab. Some of the fungi even belonged to the genus Penicillium, which we have to
thank for the development of penicillin. Now, we’re not exactly sure how old these fungi
are, but they are definitely quite old and maybe, more importantly, they appear to have
been living in isolation for eons. If that’s the case, they may have evolved specific and
unusual defenses against bacteria, which, just like their penicillin kin in that famous
petri dish, could end up being a new and powerful source of antibiotics.
And there’s one more strategy that scientists are using, one that works in espionage as
well as in medicine. And that is seeing what the enemy is up to.
While exploring life in strange new places around the world, some biologists are looking
for bacteria that have never been exposed to our drugs, but still appear to be naturally
resistant to them. Wherever we find the most naturally resistant
bacteria, we might also find natural antibiotics that we never knew about.
And here, one of the most promising leads is again in one of the hardest-to-reach places:
New Mexico’s Lechuguilla cave, a place that was isolated from all human contact until
it was discovered in the 1980’s. One of the many fascinating things that scientists
have discovered here is that the cave bacteria seem to be resistant to everything.
Even though they’ve never been exposed to us or our drugs, all of the bacteria have
proven to be resistant to at least one major antibiotic, and many tend to fend off more
than a dozen of the most powerful antimicrobials we have. This suggests to scientists that
the bacteria have evolved to be this way because they live in an environment that’s rich in
naturally occurring antibiotics, ones that the germs we live with up here on the surface
have never encountered. Now we just have to find out what exactly
those compounds are. So look, I’m not going to lie to you: we have
a lot of work to do. While we might discover a new super-drug lurking
in a cave or under the sea or in a cockroach’s head, there’s a big difference between finding
a substance that cleans house in a petri dish and actually putting a new antibiotic in the
vein of a human patient. So the bummer is, as promising as some of
these bold new discoveries may be, none of them has yet yielded an actual marketable
drug. Still, there’s a long list of successful antibiotics
that we’ve managed to derive from strange sources, starting with Dr. Fleming’s rogue
fungus. So if we keep exploring strange new places
and studying how other animals deal with the problems we’re facing, we just might find
the next penicillin before the superbugs get the best of us. Thanks for watching this SciShow Infusion,
especially to our Subbable subscribers. To learn how you can support us in exploring
the world, just go to Subbable.com. And as always, if you want to keep getting smarter
with us, you can go to YouTube.com/SciShow and subscribe.

Why (and How) Do Bees Make Honey?

Why (and How) Do Bees Make Honey?


[Intro] Hank: We all know that bees make honey, that
sweet, thick liquid gold prized by tea-drinkers, bears, and honey badgers alike, but not all
bees make honey. Insects like bumble bees, sting-less bees, and even honey wasps can
produce small amounts of honey, but the stuff you’re familiar with is the product of one
of the seven species of true honey bees. Simply put, bees make honey as a source of
food security, sometimes to eat during times of scarcity, safely stored within the hive,
and the responsibility for making this stockpile falls to the female worker, or forager bees.
They’re the ones that buzz from flower to flower, sucking up sugary nectar with their
long, tubular tongues, and they’re also the ones who build and defend the hive and take
care of the queen. These hard-working ladies do it all while the queen sits back and lays
ridiculous amounts of eggs, like, seriously, some scientists estimate that a single queen
can lay up to a quarter-million eggs in a single year and more than a million over her
lifetime. Male drone bees meanwhile basically only exist
to mate with the queen and then die, I digress. So, a worker bee collects nectar and stores
it in her crop, which is sort of like an extra holding tank, also called the honey stomach,
designed just for this purpose. Once she’s back home, she basically pukes her loot up
into another processor bee’s mouth, who then spits the nectar into a honeycomb cell. Every
time that processor bee regurgitates nectar into a storage cell, she adds a special enzyme
called invertase. The nectar is pretty much just sugar water, and therefore perishable,
but the invertase helps break that sucrose down into simpler sugar molecules, glucose
and fructose, eventually transforming it into something that will hold up in long-term storage.
At this point, the newly regurgitated nectar is still quite runny; it’s got a water content
of around 70%, while honey has a water content of less than 19%. So to remove the extra water
those ingenious little bees actually start fanning the honeycomb with their wings to
get the evaporation process cranking. Once the extra water has been fanned away and the
nectar has ripened into honey, the lady-bees seal up those comb cells using a beeswax secretion
from their abdomens. When safely sealed away within the comb, honey can basically last
forever. Pretty sweet. Thanks for asking, internet. And thanks especially
to our Subbable subscribers who keep these answers coming. They also get these episodes
a little bit early as a special thank you. If you have a quick question for us, you can
let us know on Facebook or Twitter, or down in the comments below and don’t forget to
go to YouTube.com/SciShow and subscribe.

Cockroaches, Alligators & Other Weird Sources of New Drugs


Antibiotics are one of humankind’s most amazing
discoveries. Ever since that fateful day in 1928 when Scottish physician Alexander Fleming
noticed a funny mold growing in one of his petri dishes, antibiotics have been kicking
bacterial butt. That famous mold, of course, was producing
penicillin, the founding antibiotic superstar, which has since extended the average human
life by at least a decade. It fundamentally changed the face of medicine. Antibiotics,
or antimicrobials, are basically selective poisons designed to either kill or slow the
growth of bacteria to the point where your body’s own immune system can clean up. These
drugs target a specific part of bacteria or some important stage in their development
without damaging the body’s host cells. And they’re really great their job. Until they
aren’t. Lately, antibiotic technology has been having
a hard time keeping pace with bacterial evolution. We’ve talked here on SciShow about how lots
of your die-hard, go-to favorite antibiotics are starting to lose their mojo in the face
of sneaky and rapidly evolving bacteria. The US Centers for Disease Control and Prevention
estimates that at least 2,000,000 Americans became infected with drug-resistant bacteria
in 2012, and 23,000 of them died as a result. These superbugs are deadly serious and could
quickly unleash a global health crisis if we don’t find a way to keep them in check.
The problem is we’ve already hit up many of the most obvious sources of antibiotics, like
fungi, which includes penicillin, and synthetic molecules.
Fortunately, we humans have big, delicious brains, and some of the best of them are hard
at work trying to invent all-new ways to kill dangerous bacteria or find other organisms
on the planet that are better at it than we are so we can steal their secrets. And while
they’re finding some promising leads, I gotta say, they’re looking in some pretty weird
places. [Intro] You know how everyone jokes that after some
big global disaster, only cockroaches will survive? Well, we recently found what may
partially explain their famous, and infuriating, tenacity. Research from the University of
Nottingham suggests that certain insects, like roaches and locusts, have brain tissues
that are infused with super-powered antibiotic juju. The researchers found nine different
antibiotic molecules tucked into the roaches’ nervous systems that may be protecting them
from otherwise lethal bacteria. They’re all a type of molecule known as peptides, short
chains of amino acids that make up proteins, kinda like proto-proteins. And these peptides
are specific to the bugs’ brains. They seem to be chemicals that roaches” brain cells
use to communicate with each other, y’know, whenever a cockroach is sitting around thinking
about stuff, which I guess can happen, and although we’re not sure how these peptides
actually work, laboratory tests have shown that they’re incredibly effective at eliminating
some of our least favorite bacteria, like the most dangerous strains of e.coli, which
cause gastrointestinal infections. And even MRSA, a super-resistant type of staphylococcus
bacterium that can cause unstoppable deadly infections in humans, particularly in hospitals.
In lab trials, these roach brain molecules killed over 90% of MRSA bacteria, without
harming any host cells. So I can guess what you’re thinking: shut
up and take my money! Well, hold on a sec, because we’re a bit away from having cockroach
brains on the pharmacy shelves. There’s still loads of technical hurdles to overcome, tests
to conduct, basic things we need to figure out, like how exactly these molecules work.
But roaches aren’t the only hardy animals out there. Alligators are some of the Earth’s
most rugged beasts. They essentially live in cesspool swamps teeming with bacteria and
fungus and other microbes, and more than that, they’re known brawlers. Put just a few territorial
800 pound toothy reptiles together in a dirty swamp, and you will no doubt come out with
some serious bite marks and bloody wounds, even missing limbs. But amazingly, what you
probably won’t find are any infections. This got some bayou scientists to thinkin’!
Dr. Mark Merchant, a biochemist at McNeese State University in Louisiana, helped conduct
a decade long study that investigated what makes alligators so unusually resistant to
bacterial and fungal infection. Turns out, it’s in their blood. An alligator’s
immune system is largely innate, meaning it can fight off harmful micro-organisms without
having any prior exposure to them. They just pop right out of their eggs ready to do battle.
We humans also have some innate immunity, provided by things like our skin and white
blood cells, but a big part of our immunities are adaptive, meaning we often develop a resistance
to specific diseases only after being exposed to them. Which of course is not ideal all
the time, but alligators get to skip this step. Researchers examining blood samples from American
alligators isolated their infection fighting white blood cells and then extracted the active
proteins working in those cells. And these two included a special class of peptides which
seemed to have a knack for weakening the membranes of bacteria, causing them to die. When pitted
against a wide range of bacteria including drug-resistant MRSA, these tough little peptides
proved to be effective killers. They also wiped out 6 of 8 strains of candida albicans,
a type of yeast infection that’s particularly troublesome for AIDS and transplant patients
with weakened immune systems. Such compounds may also be found in similar animals, like
crocodiles, Komodo dragons, and the skins of some frogs and toads. So far, lab trials
have shown that gator blood can kill at least 23 different strains of bacteria including
salmonella, e.coli, staph, and strep infections AND even a strain of HIV. For now, scientists
are working to find the exact chemical structures at work in four of these promising chemicals
and pinpoint which types are best at killing which microbes. One problem so far: high concentrations
of gator blood serum have already been found to be so powerful that they are toxic to human
cells. So other biologists are taking a different approach in the search for the next generation
of antibiotics. Rather than looking at other animals, they’re
exploring strange, new places, like cave soils and deep-sea sediments. Researchers have recently
discovered evidence of promising new fungi strains living way down in hundred million
year old nutrient-starved sediments in the Pacific Ocean. Everyone thought this was a
near-dead zone for life, too harsh and remote an environment for something like fungi to
survive in. Just a decade ago, the only living things known to inhabit such deep sediment
layers were single-celled bacteria and archaea, organisms known to flourish in extreme environments.
But while examining dredged up sediments from as deep as 127 meters into the sea floor,
scientists found fungi of at least eight different types, four of which they successfully cultured
in the lab. Some of the fungi even belonged to the genus Penicillium, which we have to
thank for the development of penicillin. Now, we’re not exactly sure how old these fungi
are, but they are definitely quite old and maybe, more importantly, they appear to have
been living in isolation for eons. If that’s the case, they may have evolved specific and
unusual defenses against bacteria, which, just like their penicillin kin in that famous
petri dish, could end up being a new and powerful source of antibiotics.
And there’s one more strategy that scientists are using, one that works in espionage as
well as in medicine. And that is seeing what the enemy is up to.
While exploring life in strange new places around the world, some biologists are looking
for bacteria that have never been exposed to our drugs, but still appear to be naturally
resistant to them. Wherever we find the most naturally resistant
bacteria, we might also find natural antibiotics that we never knew about.
And here, one of the most promising leads is again in one of the hardest-to-reach places:
New Mexico’s Lechuguilla cave, a place that was isolated from all human contact until
it was discovered in the 1980’s. One of the many fascinating things that scientists
have discovered here is that the cave bacteria seem to be resistant to everything.
Even though they’ve never been exposed to us or our drugs, all of the bacteria have
proven to be resistant to at least one major antibiotic, and many tend to fend off more
than a dozen of the most powerful antimicrobials we have. This suggests to scientists that
the bacteria have evolved to be this way because they live in an environment that’s rich in
naturally occurring antibiotics, ones that the germs we live with up here on the surface
have never encountered. Now we just have to find out what exactly
those compounds are. So look, I’m not going to lie to you: we have
a lot of work to do. While we might discover a new super-drug lurking
in a cave or under the sea or in a cockroach’s head, there’s a big difference between finding
a substance that cleans house in a petri dish and actually putting a new antibiotic in the
vein of a human patient. So the bummer is, as promising as some of
these bold new discoveries may be, none of them has yet yielded an actual marketable
drug. Still, there’s a long list of successful antibiotics
that we’ve managed to derive from strange sources, starting with Dr. Fleming’s rogue
fungus. So if we keep exploring strange new places
and studying how other animals deal with the problems we’re facing, we just might find
the next penicillin before the superbugs get the best of us. Thanks for watching this SciShow Infusion,
especially to our Subbable subscribers. To learn how you can support us in exploring
the world, just go to Subbable.com. And as always, if you want to keep getting smarter
with us, you can go to YouTube.com/SciShow and subscribe.

Bullet Ant Venom

Bullet Ant Venom


– So the other group of ants
[Dr. Corrie Moreau, curator/ants] that we have today are bullet ants.
[Dr. Corrie Moreau, curator/ants] – Why are they called bullet ants?
[Bullet ant, Paraponera clavata] – Well, they’re called bullet ants
[Bullet ant, Paraponera clavata] because their sting is so painful
[* causing excruciating pain, numbness & trembling] it feels like you were shot by a gun.
[* causing excruciating pain, numbness & trembling] – And you’ve experienced
this firsthand? – I have, just once, I’d like
to keep it that way. And so you can see they’re
actually quite tremendous ants, I mean, they’re really foreboding,
[* worker bullet ants are 18–30 mm long] they’re crazy big and they’re cool.
[* worker bullet ants are 18–30 mm long] – Are they the largest ant? – They’re one of the largest ants. There’s another genus called Dinoponera.
[Dinoponera, Dinoponera australis] In some ways larger.
[* females may surpass 30–40 mm in length] Not as painful of a sting, though.
[* females may surpass 30–40 mm in length] This is Paraponera.
[Bullet ant, Paraponera clavata] We’re studying the gut bacteria
actually in this group of ants. But we’re also
interested in the venom. And so what I was telling
you is part of the reason I brought them back
alive is that at one point I had tried to milk them, because
my colleague was like, “It’s because we weren’t sure if
we’d have permits to bring back alive.” – Yeah.
– You can just milk them. So I can show you how
I attempted to do it and I will tell you that it
didn’t work in the end. When I got the venom back
it was actually not usable. But let me grab my equipment. – It’s not every day you get to
milk a venomous ant. At work. – So this is our fancy equipment. So if you think about, like, how they milk the venom
from spiders, right? Usually they just have
them bite something and squirt the venom inside
and it’s the same principle. So again, we just have
our empty tubes, and we have a little
bit of parafilm, right, which is essentially just like
a waxy kind of paper-y thing that we can stretch
across the top of this. And we’re going to get them
to try to sting through the tube and deposit their venom
on the side of the tube. – Wow.
– Yeah. One thing I have noticed is, what’s really interesting
actually, is with these bullet ants, when you collect them in the
wild they’re incredibly aggressive. You disturb them at all, and they
just go into immediate attack mode. In fact in the field, if you
even like blow on them, you can physically
hear them stridulate, which is a way of communicating
between individuals. And now that they’ve been
in the lab for just a few days, they’re actually almost docile. And so I’m curious to see whether
they’ll even sting through this. But we’ll try. Yeah, see, this one stridulates. So now let’s see if we
put her abdomen up, yeah, she is depositing
her sting through. – Oh!
– See that? – Sting it! Sting it! – So you see, she’s got her sting out, this is where I don’t want
to lose control of her. She’ll try to sting through, oh, there, you saw that sting go? That’s huge.
– Yeah. Wow. Focus your anger. – We will try to get another one to sting
– Come on, ladies. – You look like a new victim,
raaah, let’s get her all mad. – Yeaaaah! Oh, she’s stridulating. – She’s actually kinda not
mad as much anymore. – They’re—they’re just
like, they’re like, “Corrie, we wanna hang out,
I thought we were cool.” – I know, that’s probably
exactly what they think. – Like, “Come on, Corrie,” “I read your latest paper about
climactic regional distribution” “of my sister species.” I don’t even know if that’s
what you’ve written about, I don’t even know if that—
those words even make sense. – You don’t read all my
scientific publications? – Um, I probably couldn’t
get through the abstract. Not—not just yours, but most. – I won’t take it personally. Oh, yeah, she’s got a very big sting,
so let’s see if I can get her to— – Yeah. Sting it. – So that’s how you milk a
bullet ant for their venom. So essentially, just getting them
to sting through this material, they have now
deposited their venom all over the top of this
and inside of that tube, so I can just shove
that in there and then take it back
to an analytical lab to look at what are the—what’s
the chemistry within the venom. Now, I’ve already told you that
that didn’t work so successfully, so in a sense, what we need to do
is dissect out the venom glad, and that’s where it
gets a little more tricky, because in this case, you
can see they’re big and— – Cranky. – Cranky. And they
don’t like to hold still. Do this under the microscope. Okay, so now, again, we’re
gonna just pull off her abdomen, oh God, these are some tough ants.
[* abdomen] Even tougher than the bullet ants.
– Wow. – So now we’ve got—
– You did it. – —her body separated
from her abdomen. I wanna just tease apart some
of the parts of the abdomen and then we can usually pull the
venom gland out through the sting. So I’m just gonna start
pulling apart the body, and since I don’t want to
rupture the venom gland, I wanna try not to stab too much. – Yeah, this is meticulous work, dissecting ants.
– Yeah. – What is the smallest ant that
you’ll work on under a microscope? – Oh, I’ll work on anyone. – Even the ones
that are so small that you can’t even see
them on the labels? – Yep, even those. I’ve had to
dissect out their guts, too. – How do you even get
forceps that small? – Suspense, right?
– Yeah, the pressure. – Yeah, nothing like having
to dissect on camera, too. As if it’s not hard enough, right? – Yeah, all the viewers are
at home, quietly judging you. They’re like, “Well, when
I dissected ants last—” – I was thinking they were biting
their fingernails in suspense. – Yeah, that too. – So at the one end, let’s see if I can put it
in a good orientation— you can actually
see the left side, if you look through
the microscope, you can actually see the sting hanging all the way out.
[* sting] – Oh yeah!
– It’s like a giant hypodermic needle. – Yeah. – And then starting at the
other end on the right side, we can actually start to see
those parts of the digestive system. So first you have the crop, right?
[* crop] So it’s that social food sharing organ,
which then transitions into the mid gut and then into what’s called the ileum
[* mid gut, * ileum] and then finally into the rectum,
[* rectum] and then alongside that is where the venom gland sits.
[* venom gland] – That’s amazing.
– Yeah, it’s really awesome. One of the things that’s cool
when you first open them up is that the contents within the gut, you can see fat and
you can see the trachea and all those other things,
and even within the gut, it’s either clear like it
almost looks like water, or sometimes you can see
things that look like waste, but within the venom sac,
it’s actually almost like oil. And so when you burst it,
it’s literally like oil coming out, not like liquid, like, you
know, in the same sense. – Cool.
– Yeah. – Nice.
– So now the question is, are you gonna hold
a bullet ant for 10 seconds? The Brain Scoop is brought to you by the Field Museum in Chicago It still has brains on it.

Attack of the Super Bugs

Attack of the Super Bugs


What potential disasters keep you up at night? Meteor strikes? Super Volcanos? World War Three? World war Z? Those are all pretty scary and we didn’t even mention climate change but there’s one other immediate terrifying, scientific problem that rises above the rest… Superbugs I’m not talking about giant spiders of Mirkwood or tracker jackers. I’m talking about antibiotic resistant bacteria. Which by the way are everywhere. Antibiotics are pretty incredible. Since the discovery of penicillin they have extended the average human life by about 10 years. A good percentage of the people watching this right now are only alive today because at some point an antibiotic saved their life. But we’re facing a little bit of a crisis. Antibiotics are starting to loose their effectiveness as bacteria continue to outsmart our technology. And I don’t wanna make you too paranoid here, but the consequences could be big. Remember that little thing called the black death – a pandemic that ravaged Europe and Asia in the 1300s, killing about, meh, 25 mln people. That wouldn’t have happened if antibiotics were a thing back then, but if our drugs stop working now, could it happen again? The US Centers for Disease Control estimates that 23,000 American died in 2012 from antibiotic-resistant bacteria. And the World Health Organization says that in 2010 about half a million people were infected with a resistant strain of tuberculosis, a third of whom died. A post-antibiotic era could essentially mean the end of modern medicine and suddenly a simple operation, sinus infection or a scraped knee could once again have the potential to kill. Now, I’m not saying you should be worried about this. Actually, yeah, I’m saying you should be worried about this. When Scottish physician Alexander Fleming got out of bed one September morning in 1928 he had no idea that he was about to change the world. Fleming had seen countless soldiers die from infected wounds and since the 1st World War ended, he’d been working hard to find better antibacterial agents. He was a good guy and a good scientist, but he was also a bit of a slob. So that morning he was straightening a stack of Petri dishes, where he’d been growing a staphylococcus bacteria, when he noticed mold in one of the dishes. Now, his lab was messy enough that that wasn’t that weird, but what caught his eye was that all around the mold the bacteria was dead. He later identified that mold as penicillium notatum. Years of experimentation followed and after enlisting the help of researchers Howard Florey and Ernst Chain the team figured out how to grow and use the fungus to treat bacterial infections. Mass production began during World War II and by D-Day in 1944 all allied soldiers had penicillin, the world’s first antibiotic. For their work Fleming, Florey and Chain were awarded the Nobel Prize. And, for the next 50 years, or so, antibiotics were unbeatable, saving lives left and right. But lately they’ve struggled to perform as well as they used to. Before we talk about exactly what antibiotics are and how they work, you have to understand what they’re up against. Bacteria!!!! Take a look around your room. Everything, your chair, your sandwich, your dog, your body – inside and out – it’s all covered in millions and millions of different single-celled bacteria. They can pretty much survive anywhere. Even in radioactive waste and in the absence of light and oxygen. But unlike viruses, which need a host cell to reproduce and survive, bacteria can thrive everywhere, because they can share their genetic material with each other. This is the key to their evolving resistance to antibiotics. While some bacteria have genes that make them resistant to like heat, so they can live in boiling water, other bacteria may be resistant to penicillin and both kinds can share what they know. We get our genes from our parents and what we’re born with we’re stuck with our whole lives. Bacteria, however, like to do things a little differently. They don’t to use traditional reproduction to pass their genes along. They can use something called horizontal gene transfer to swap genetic information, like you swap Pokemon cards. And one of the best ways bacteria acquire new genes is to loot their neighbors’ body when they degrade and die. This process is known as transformation, although some pathologists have dubbed it “the funeral grab”. It happens when bacteria are in a special physiological state called competence, during which they can scavenge bits of foreign DNA from their environment. So say Bobby bacterium dies and then Benny bacterium creeps up and grabs whatever genes it wants. So if Bobby was resistant to cold and Benny grabbed that gene, now Benny is suddenly cold resistant. And if Bobby was resistant to a certain antibiotic, boom, now Benny is too. Another way bacteria exchange genetic materials is by passing viruses, also known as transduction. Viruses can infect bacteria just like any other organism and because viruses are just bits of RNA or DNA, they can jump into a bacterium, latch onto some genes and then jump to a different bacterium, transferring those genes in the process. So that’s like I caught the flu from you and with it I got your mother’s eyes. The third way bacteria exchange traits is through conjugation, which is kind of like sex. So let’s say Bobby and Benny E. coli are feeling frisky and Bobby builds a gene passing connection over to Benny and when they break apart Benny can now do something that only Bobby could do before. So you see where this is going. A particular strain of bacteria could suddenly become resistant to an antibiotic by catching a virus, robbing a dead friend or by having sex with a live one. And just like the evolution of any other organism the bacteria that acquire the toughest, most resistant traits become more fit, more adaptable to a range of environments, and are thus more likely to survive and thrive. So in a way the superbug phenomenon, that’s going on right now, is kind of like watching natural selection played out in fast-forward, which is cool and scary. But now you have a sense of how high the stakes would be if say a resistant strain of the plague started moving around the globe. But luckily, for the last 70 years, or so, we’ve had antibiotics, also called antimicrobials or antibacterials. And they work by either destroying the bacteria or slowing their growth enough that the human body’s own immune system can finish the job. Basically an antibiotic is a selective poison designed to find, bind and kill bacteria, without damaging their host cells in your body. These drugs usually work by attacking a unique bacterial target, like a particular protein, or a bacterial process, like the way they build a cell wall or metabolise sugar. For example most bacteria build their cell wall using a specific combination of sugars and amino acids, a combination that our cells don’t use. So antibiotics like penicillin block the production of that material, so the bacteria’s wall is weakened and bursts. Other antibiotics may attack bacteria’s metabolic pathways. All cells require folic acid, aka vitamin B9, to function. This vitamin easily passes into human cells, but it can’t enter bacterial cells. So bacteria have to make their own. The sulfa family of antibiotics, made from a sulphur compound, works by disrupting the production of this vitamin, thus inhibiting their growth. And then there’s tetracycline, which combats infection by attacking how bacteria make protein. Tetracycline can get through bacterial membranes and disrupt protein production, enough to inhibit cell growth, while human cells remain safe. But as amazing as antibiotics are, they’ve got a really smart enemy and bacteria have a few effective ways of wriggling out of the crosshair. For one, some bacteria can basically just barf up the antibiotic when it gets inside it’s cell. They use their chemical energy to fuel what are essentially pumps that spit the antibiotics right back out of the cell, before it can do any harm. They may also get kind of sneaky and change the drugs target, so that the antibiotic can’t find what it’s supposed to destroy, because many antibiotics work only in a very specific molecule. If a bacterium can replace that molecule or rearrange it’s structure, that antibiotic can’t do it’s job. Bacteria can also go on the offensive and basically make a weapon that looks for and breaks down antibiotics. For example, some strains can produce enzymes that destroy penicillin by breaking open the compound that’s basically it’s active ingredient. And, of course, once a bacterium has figured out a good resistance it can pass that information along to it’s neighbors, through sex or viruses or pilfering and then it’s on to other human and animal hosts who travel all over the globe by land sea and air. And then it’s “goodbye drugs – hello plague”. So now you might be wondering – well, can’t we just develop new antibiotics? Well, we’ve already gone after bacteria’s most obvious targets. And what’s left are increasingly difficult alternatives. Basically, new classes of antibiotics will be a lot harder to discover and develop. We’re probably not gonna find them in a moldy lunch box. However, researchers at Oregon state university and other institutions around the world are working on a promising new antibacterial agent, called PPMOs. Lab studies have shown, that one type of PPMO has been really effective at controlling some kind of bacteria that I can’t pronounce. Which happens to be responsible for a lot of hospital infections. PPMOs are lab synthesized analogs of DNA or RNA. They target a bacterium’s genes, instead of just disrupting it’s cellular function. Although they haven’t been tested on humans yet, PPMOs may offer a totally different approach to fighting bacterial infections and possibly even other diseases with genetic components. Other researchers are looking at fighting superbugs with viruses. Bacteriophages are viruses that infect and destroy bacteria and spread to other bacteria. These phages are naturally occurring and can be found all over the place, including soil, river water and the human body. Each phage is specific to a particular type of bacteria and needs the proper host to multiply. The more targets it has, the faster the virus spreads and kills, making it especially effective against high concentrations of bacteria or chronic infections. You only need a tiny bit of the virus, which can be administered through a cream or a spray. And, so far, they don’t seem to infect human cells and they haven’t contributed to antibiotic resistance. So even though the risk of superbugs taking over the world is real and scary, we do have some reasons to be hopeful. And, in the meantime, there are some things you can do to help. First, it’s important to understand when you should and shouldn’t use anitbiotics. You don’t wanna gobble them up every time you feel kind of poopy. You might have a virus and antibiotics won’t help that. Antibiotics should be a last resort reserved for serious infections, when other treatments haven’t worked. And if you do need them, make sure you take them exactly as prescribed until the bottle is empty. Stopping early only makes the surviving bacteria stronger. Likewise, never take antibiotics without a prescription. No passing along left-over medication. And of course make sure you wash your hands, use soap, get vaccinated. If you prevent illness, you prevent the need for medications in the first place. The future peoples of earth will thank you. Thank you for watching this SciShow infusion, especially to our Subbable subscribers who keep these episodes coming. If you’d like a little bit of SciShow for yourself, like a SciShow tie or a chocolate bar, you can go to subbable.com to learn more. And if you have any questions or ideas for an episode you’d like to see, you can find us on Facebook and Twitter and as always in the comments below. If you wanna keep getting smarter with us you can go to youtube.com/scishow and subscribe.

Romantic Ants

Romantic Ants


Hey! We’re here with Corrie Moreau, who’s the curator of insects here at the Field Museum. – Hi!
– Hey! And today, we’re going to talk about ants! – And ant sex. For Valentine’s Day.
– Yeah! ‘Cause there’s nothing more romantic than ant sex. – So this is actually a worker of a turtle ant in the genus Cephalotes. One of the things I love about this ant is sort of the remarkable anatomy of it. So you see this head capsule is a totally different shape than all the other individuals in the nest. So most individuals in the nest look like this small one here, where they don’t have this odd-shaped head. Where, in the larger individuals in the nest, we actually see that they have this large head capsule- and you see it almost looks like a dinner plate or a saucer. That’s because they block the nest entrance of the hollow twigs they live in. So they act just like a living door. So all day long, all they do is sit and block the nest entrance.
– They just like… – Yes, absolutely.
– With their face in the door. Don’t they get bored? – Probably.
– Probably? – People often think of ants as being, you know, the strong and mighty ones like this, the workers and the soldiers as being male. But it turns out almost every any you’ve ever seen in your life is female.
– No way. – If you’ve ever seen an ant without wings, it’s female.
– Why? What’s the benefit of only having one sex in an entire colony? – So in this case, it has to do with relatedness. So you can imagine that we have all of these individuals that have forgone the ability to reproduce, to have sex. Right, so there has to be some benefit to them. And so, what happens is that sisters are more closely related to each other than they are to their brothers or even their mother. – Really? Why?
– Yeah. So it’s called haplodiploidy. So unlike us—where in order for a new offspring to be formed you have to have the sperm and the egg unite, and then you get half of your genome from your mom, half from your dad— in hymenopteran, including the ants, the way that it works is that females are produced when an egg and sperm are united, but if no sperm is ever introduced to that egg, that becomes male. So a male only has half the size of the genome. – So, if there are no males like existing in these societies, how do they get sperm then? – Yeah, that’s a good question. So, in the ants, about once a year, they make sexuals; or the males, and the new females—the virgin queens— and they go off on mating flights and reproduce, and then the males die almost right away. Now the female, who’s mated just this once in her first year of life, she flies around and finds a new habitat, digs down and starts a whole new colony of all females. And she stores all that sperm in a special organ inside her body—it’s called a spermatheca— – I’ll play that word in Scrabble next time. – And then she can store that sperm for her entire life, so sometimes it’s for a few years, sometimes up to 25 years. So she never leaves the nest again, she never mates again. She just lays an army of all female workers and then once a year produces sexuals. – So, just to clarify, she’s got all this sperm stored up within her body, and she can produce females without needing to draw from that sperm bank. – No, the females she uses to draw from the sperm bank. The males are just eggs that are unfertilized. – What?
– I know, it’s cool. – That is crazy.
– Yeah, yeah. And so in insects, the way that they reproduce is that the males have essentially a penis, but it’s called an aedeagus, and that’s the sort of delivery vehicle to the opening in the female. This is actually a female queen. You can see her sting right there?
– Wow. Yeah! – And that’s what she would deliver a venom from, right? And that’s right above where she can lay eggs. So actually in this case her sting is a modified ovipositor but is now no longer used for egg laying; it’s actually just used for venom delivery. These are called bullet ants. I actually have a whole giant tub of them here. These are found in Central America and South America and they’re called bullet ants because their sting is so painful it feels like you’ve been shot by a gun.
– REALLY? – Yeah, here, you can hold one.
– Have you ever been stung by o—I don’t know if I want to hold it! Even though it’s dead! – I have been stung by one once. It was really hot. I actually got stung right on the tip of my finger and it was like my finger had a total fever—shooting pain up my arms…it’s really pretty terrible. And in this case, I mean, I got stung pretty minimally, but I know people who have been stung by like 20 at once and then had to be carried out of the rainforest. – Oh my gosh!
– Yeah, it’s really terrible, and then you have fevers and flu-like symptoms for several days. – Can you die?
– I think the only way you would die is if you had anaphylactic shock. So just essentially if you were allergic like a honey bee. The turtle ants that I was showing you earlier, these girls here, actually have no ability to sting. Their sting’s been so reduced that they don’t sting, and then their jaws are so little they can’t bite. They’re the perfect ant: they don’t bite or sting, and they’re beautiful! But then another group of ants that I brought actually, are army ants, and one of the things I love about army ants is the soldiers can become so highly modified. I mean, you almost can’t even recognize them, necessarily. These are two sisters from the same colony, from the same mother.
– Woah. – Yeah, exactly. So this little tiny one at the bottom: the role of that individual is really to go out and do all the foraging, the nest cleaning, the caring for the larvae. Where these big soldiers here, not only are they much bigger, but their whole role is defense. And so you can see from their mandibles or their jaws.
– Oh my gosh. – Yeah, they’re essentially these tusks, right?
– Woah. – So they come down to these, almost like, pure spikes on the ends of their face and their jaws have become so highly modified for defense and nothing else. They can’t even feed themselves anymore. I mean imagine, there’s no way you can get food from here up to your mouth up there, right? So they actually rely on other workers to carry food and place it into their mouth. – Really?
– Yeah! It’s really amazing.
– That’s amazing! I can’t imagine my sister coming up to me and like, hand-feeding me. That seems so strange. – Ants, it turns out, have helpful gut bacteria, just like we do, so we can actually study the bacteria using DNA based technologies to investigate how they’re actually processing the food that they bring to the colony. And one of the really cool things is that all ant species actually have mouth-to-mouth food sharing; it’s called social trophallaxis, where they just essentially regurgitate to each other.
– Really. – But in the case of the turtle ants in particular, because they also need to share their gut microbes, mouth-to-mouth isn’t very good, so they participate in oral-anal trophallaxis to reacquire their gut microbes. – Wh— They like eat— They eat poop? – That’s essentially right. So just like termites in order to re-seed their stomachs after metamorphosis, ants do that as well. So they actually have to find another individual that has a good, healthy gut community and lick the rear end of their sister. – Oh my god. The Brain Scoop is brought to you by The Field Museum. …it still has brains on it.

Are There Really Insects in Yogurt?

Are There Really Insects in Yogurt?


Strawberry yogurt. It makes for a quick, delicious breakfast
or mid-afternoon snack. You might think its pink color comes from
the red strawberries mixed with white yogurt, right? Well, if the ingredients include carminic
acid, cochineal [coach-ih-NEAL], E120, or Natural Red 4: your yogurt is actually colored
with /powdered insects/! You can also find this bug-based dye in other
pink and red foods, like jello and candy, plus some cosmetics like lipstick. And even though insects in your food may sound
kinda gross, it /is/ a natural dye, and perfectly safe to eat as long as you’re not allergic
to it. This bright red dye is produced by a specific
kind of true bug: female cochineal scale insects. They live and breed on prickly pear cacti,
and have been harvested for dye for hundreds of years. While the winged males can fly to mate and
escape predators, life as a female scale insect is pretty simple: suck sap and protect yourself. The first thing she does after hatching is
stick her mouthparts into her host cactus and start feeding. She stays there her entire life, and uses
a couple tricks for protection: secreting a waxy, white coating and synthesizing carminic
acid. The carminic acid molecules are stored as
clumps in her hemolymph – the insect equivalent of our blood – and ward off some would-be
predators, like ants, and harmful microbes. Carminic acid also happens to be bright red. And these cochineal insects can be packed
/full/ of it – up to around 20% of their dried bodyweight! Each bug is about as big as a grain of rice,
so you have to collect, dry, crush, and process tens of thousands of them for each kilogram
of cochineal dye. It’s intense work, but scale insects have
been farmed by the Aztec and indigenous people of Mexico since at least the 10th Century. And the dye was a massive hit with the Spanish
colonials in the 16th Century after they conquered these peoples. They treated cochineal like “red gold,”
and were the first to sell cochineal products – mostly dyed fabrics – across the world. Today, the main exporters of the red dye are
Peru and the Canary Islands, where the bugs are farmed on prickly pear plantations. So, not everyone’s happy with the idea of
a bug-based dye, even though humans have been using it for centuries. But there are less buggy ways to give strawberry
yogurt a pink hue. There’s lycopene [LIE-co-peen], from tomatoes,
and anthocyanins [an-tho-SY-an-ins] from red cabbage. And there’s always… y’know… just leaving
the pale color from the strawberries alone. Thanks for asking, and thanks to all of our
patrons on Patreon who keep these answers coming. If you’d like to submit questions to be
answered, or get these Quick Questions a few days before everyone else, go to patreon.com/scishow. And don’t forget to go to youtube.com/scishow
and subscribe!