Hey there! Have you ever wondered why some people on the internet don’t seem to like koalas? Let’s dive into some of the myths and facts about these adorable creatures and see what science has to say!
There’s a rumor going around that koalas have the smallest brains of all mammals and that they can’t think because their brains are smooth. But let’s break this down. Scientists used to believe that animals with bigger brains compared to their body size were smarter, but that’s not always true. The idea that koalas have tiny brains came from a shriveled brain that had shrunk after being preserved. In reality, living koalas have average-sized brains for marsupials. And about those brain wrinkles? While humans and some other animals have wrinkly brains, which might help with complex thinking, many smart animals like birds and octopuses have smooth brains. So, wrinkles aren’t everything!
There’s a story that if you put eucalyptus leaves on a plate, koalas won’t recognize them as food and might starve. But no koala expert has confirmed this. Koalas are very picky eaters because eucalyptus leaves are low in calories and nutrients. They prefer fresh leaves over older ones. So, ignoring leaves on a plate might actually be a smart move for them!
It’s true that koalas are slow, but it’s not because they’re getting high from eucalyptus leaves. These leaves are toxic to most animals, but koalas have special gut bacteria that help detoxify them. Their long digestive tracts take a lot of time and energy to process the leaves, which is why they conserve energy by being slow and sleepy.
Many plant-eating animals wear down their teeth over time, but koalas live long enough for this to become a problem because they have few predators. When their teeth wear down, they chew partially-digested food again, which might sound gross, but it’s a clever way to deal with the issue.
Baby koalas need to eat their mom’s feces to get the special bacteria that help them digest eucalyptus leaves. This might sound strange, but it’s not unique to koalas. Baby elephants and pandas do something similar, but they don’t get criticized for it.
So, even though koalas might seem quirky, they’re actually pretty amazing animals. They have unique adaptations that help them survive in their environment. Next time you hear something negative about koalas, remember all the cool things that make them special!
Thanks to Toby from the channel Tibees for voicing the koala in the video. If you’re interested in learning more about math, astronomy, and science history, check out her channel. She’s doing awesome work!
Research and create a poster comparing the brain sizes and structures of different animals, including koalas. Highlight how brain size doesn’t always correlate with intelligence. Present your findings to the class.
Conduct an experiment to test how koalas might react to eucalyptus leaves in different settings. Use paper cutouts to simulate leaves and observe how classmates “koalas” respond to them on a plate versus in a tree setting. Discuss why koalas might prefer one over the other.
Role-play the digestive process of a koala. Assign roles such as the koala, eucalyptus leaves, and gut bacteria. Act out how the koala processes the leaves and how the bacteria help detoxify them. Reflect on the importance of these adaptations.
Create a simulation to demonstrate how koalas manage tooth wear. Use clay to model koala teeth and simulate the chewing process. Discuss how this adaptation helps them survive longer despite their teeth wearing down.
Participate in a debate about the unique adaptations of koalas. Take sides on whether these adaptations are advantages or disadvantages. Use evidence from the article to support your arguments and conclude with a class discussion on the importance of adaptations in survival.
Here’s a sanitized version of the YouTube transcript:
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[Cameron] The internet loves honey badgers, kittens, and tardigrades. But hey, koala, do you know what the internet thinks about you?
[Koala] That I’m cute and cuddly, right?
[Cameron] Well…
[Koala] What the…
[Cameron] …well, this is awkward. I’m Cameron, and this is MinuteEarth. It turns out that much of the negative information about koalas on the internet just isn’t true. So let’s go through it and see what science has to say.
[Koala] OK, so according to the internet, I have the tiniest brain of all mammals. On top of that, my tiny brain has no wrinkles, which means that I apparently “can’t think.”
[Cameron] Ouch. There’s a lot to unpack here. First: We used to think that animals with bigger brains relative to their body size were smarter than animals with relatively smaller brains, but that’s not exactly how it works out. Plus, we could spend all day debating what “smarter” means for an animal, anyway. Second, we used to think koala brains were absurdly small relative to their bodies, but that impression came from a shriveled brain that had significantly shrunk after being preserved. Brain scans on living koalas show that their brains are basically average-sized, at least for a marsupial. And about those wrinkles, or lack thereof: We humans are used to looking at primate brains, which tend to have that walnut-like surface. Scientists think that these wrinkles increase the brain’s surface area enough to make more connections between more neurons, which does imply that wrinkle-less brains might be less complex than wrinkly ones. But birds’ brains are smooth, and some species can make tools and communicate in complex ways. And the famously intelligent octopus has a smooth brain. So wrinkles aren’t everything.
[Koala] It says here that if you pick eucalyptus leaves and lay them out on a plate, I won’t recognize them as my food, and I will starve.
[Cameron] Being unable to recognize your own food does sound pretty bad. But no koala expert I talked to could confirm this anecdote. Regardless of whether they recognize leaves on a plate as food or not, there’s actually a good reason koalas might not want leaves on a plate. Even the most nutritious eucalyptus leaves are pretty low in calories and nutrients compared to other food, so koalas are really picky about which leaves they eat; they generally don’t bother with older, less nutritious fallen leaves. And leaves on a plate would probably look and smell a lot like fallen leaves to a koala. So ignoring those leaves is actually pretty clever.
[Koala] OK, well speaking of eucalyptus, apparently I’m lethargic all the time because eucalyptus leaves are toxic.
[Cameron] To be fair, you are pretty slow, and that is totally because of your food. But you are not getting high. Eucalyptus leaves are toxic to most animals, but not to koalas. That’s because koalas have super-long digestive tracts – including a six-foot long caecum – full of specialized gut bacteria that detoxify the leaves. But all that digestion takes a lot of time and energy – and remember, the leaves aren’t that nutritious to start with – so koalas have to be energy efficient, which does make you act kind of lethargic.
[Koala] Apparently, we wear our teeth down to the point where we can’t chew anymore, and then starve and die.
[Cameron] This isn’t fair. Many other plant eaters wear their teeth down over time by near-constant chewing, but they all tend to die before their ground-down teeth become an issue. But koalas have so few natural predators that many live long enough for chewing to become difficult. At that point, koalas compensate by regurgitating partially-digested food to chew it again, which, I assure you, is not your grossest behavior.
[Koala] No, it’s not – I once ate my mom’s feces. The internet also makes fun of us for that.
[Cameron] Yeah, that…the technical term is “fecal pap.” Remember those detoxifying gut bacteria? Baby koalas aren’t born with them; they have to eat their mother’s feces to colonize their digestive tracts. And that is unusual, but it’s not uniquely unusual. Baby elephants do basically the same thing, but they don’t get the same criticism. Same goes for panda babies, which I’m pretty sure the internet has determined to be the cutest things around.
So hey, koala, don’t let the negativity get you down. Sure, you’re sleepy, slow, and a bit quirky, but as far as animals go, you’re pretty remarkable. I’d like to thank our friend Toby from the channel Tibees for voicing the koala in this video. If you’re interested in deep dives into mathematics, astronomy, and the history of science, make sure to check out her channel Tibees. She’s doing great work over there. Bye!
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This version removes any inappropriate language and maintains a respectful tone throughout the transcript.
Koalas – Koalas are marsupial mammals native to Australia, known for their tree-dwelling habits and diet of eucalyptus leaves. – Koalas spend most of their time in eucalyptus trees, where they eat and sleep.
Brains – The brain is an organ in animals that serves as the center of the nervous system, responsible for processing sensory information and controlling behavior. – The human brain is capable of complex thought processes, allowing us to solve problems and make decisions.
Eucalyptus – Eucalyptus is a type of tree native to Australia, known for its aromatic leaves that are a primary food source for koalas. – The strong scent of eucalyptus leaves can be detected from a distance, and they are often used in medicinal products.
Leaves – Leaves are the flat, typically green parts of a plant that are involved in photosynthesis and gas exchange. – The leaves of the plant capture sunlight and convert it into energy through photosynthesis.
Bacteria – Bacteria are microscopic single-celled organisms that can be found in various environments, some of which are beneficial while others can cause disease. – Certain bacteria in the soil help plants grow by breaking down organic matter and releasing nutrients.
Digest – To digest means to break down food into smaller components that can be absorbed and used by the body. – Humans rely on enzymes in their stomachs to digest the food they eat.
Mammals – Mammals are a class of warm-blooded vertebrates characterized by the presence of mammary glands, hair, and three middle ear bones. – Whales, despite living in the ocean, are mammals because they breathe air and nurse their young.
Predators – Predators are animals that hunt and eat other animals for food. – Lions are apex predators, meaning they are at the top of the food chain in their ecosystem.
Adaptations – Adaptations are traits or behaviors that help an organism survive and reproduce in its environment. – The thick fur of polar bears is an adaptation that allows them to stay warm in the Arctic climate.
Nutrients – Nutrients are substances that provide the necessary components for growth and maintenance of life. – Plants absorb nutrients from the soil, which are essential for their growth and development.
