Have you ever heard of tardigrades? These tiny creatures, also known as “water bears” or “moss piglets,” are some of the most intriguing organisms on our planet. Let’s dive into their mysterious world and discover what makes them so special.
Tardigrades are microscopic creatures that are so small you usually need a microscope to see them. Imagine about 20 of them fitting on your little finger! Although they are tiny, they have a unique appearance with four pairs of legs and a face-like structure. They are part of a group of organisms that are hard to classify, sitting somewhere between nematodes and arthropods.
One of the most amazing things about tardigrades is their ability to survive in extreme conditions. They are known as extremophiles, meaning they can live in places that are too harsh for most other life forms. Whether it’s the freezing cold, boiling hot springs, or even the vacuum of outer space, tardigrades can handle it. In fact, they have even been sent to space on NASA missions and managed to survive and reproduce there!
Scientists have discovered something fascinating about tardigrades: they have a significant amount of foreign DNA. A study from the University of North Carolina found that up to 18% of their DNA comes from other sources. This foreign DNA likely comes from the algae and fungi they live with, not from outer space as some headlines might suggest. This ability to incorporate foreign DNA might help them survive in extreme environments.
Did you know that tardigrades have been intentionally sent to space? These experiments, sometimes inspired by curious school kids, aim to see how these extremophiles cope with the harsh conditions of space. Tardigrades are the only known creatures to go to space and return with all their life functions intact. This raises exciting questions about the possibilities of life beyond Earth.
Dr. Meg Leman from the California Academy of Sciences is an expert on tardigrades. She loves sharing her knowledge and enthusiasm for these tiny creatures. If you’re ever in San Francisco, you can visit her at the academy and learn more about these incredible organisms. Dr. Leman also shares information online through her website and Twitter, where she posts updates about her research.
Tardigrades are truly remarkable creatures. Whether you find them cute or not, there’s no denying their incredible ability to survive in the most extreme conditions. They challenge our understanding of life and inspire us to think about the possibilities of life in the universe. So, what do you think? Are tardigrades fascinating or what?
Don’t forget to explore more about other amazing creatures like octopuses, which can change their skin color and texture. Keep learning and stay curious!
Using clay or playdough, create a model of a tardigrade. Pay attention to their unique features such as the four pairs of legs and the face-like structure. This will help you understand their anatomy better. Share your model with the class and explain the features you included.
Research and design a simple experiment to test how tardigrades survive extreme conditions. While you may not have access to real tardigrades, you can simulate conditions like dehydration or freezing with other materials. Present your findings and discuss how these conditions relate to tardigrade survival.
Join a group discussion about the role of foreign DNA in tardigrades. How might this contribute to their survival? Prepare by reading about genetic adaptation and be ready to share your thoughts on how this might apply to other organisms.
Imagine you are a scientist planning a mission to send tardigrades to space. What experiments would you conduct? What do you hope to learn? Write a short proposal and present it to the class, explaining the significance of studying tardigrades in space.
Prepare questions for a mock interview with Dr. Meg Leman. What would you like to know about her research on tardigrades? Conduct the interview with a classmate acting as Dr. Leman, and share interesting insights with the class.
Here’s a sanitized version of the provided YouTube transcript:
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Rumor has it that tardigrades have DNA from unknown sources. Can that even be possible?
Hey everyone, I’m here with Dr. Meg Leman from the California Academy of Sciences in San Francisco, and we’re going to take a deeper look at the mysterious tiny world of tardigrades.
Welcome! Thanks for joining us.
Thank you! What fun to be here and talk about my favorite subject.
Yes! All right, let’s get right into it. So first of all, do you have a favorite pet name for tardigrades? Do you like “water bears” or “moss piglets”?
Oh, I love “water bear” because it’s so cute, but “slow walker” is technically accurate. “Moss piglet” is kind of a fun name, isn’t it?
When you need to get someone’s attention, I brought one to share with you.
It’s a little life-like but kind of large. They’re not really blue, but they are cool, aren’t they?
What do they actually look like? You can’t see them with the human eye, right?
Correct! I think about 20 could fit on my little finger. Technically, a few are large enough that you could see them if you had a hand lens, but usually, it requires a microscope to see them. That’s what’s so cool; we hardly know anything about them.
What are some of the most interesting facts about them?
They are the number one extremophile. That means they can live in extreme places. They can survive in really cold climates, hot springs, and even outer space. They sent some on one of the NASA flights, and they even had babies in space! They can go into a little ball sometimes, which is called cryptobiosis, and stay in that stage for over a hundred years. We’ve been able to find them in dried plant collections that are over a hundred years old by putting a drop of water on them and having them come back to life.
So if I were to look at one of these little guys underneath a microscope, what would I see?
Right! If you looked under a microscope, you would say, “Oh, it’s so cute!” I’m sure you would. They have four pairs of legs and what appears to be a face, but obviously, it’s not the same sense as we have. They don’t totally see, but they do have the rudiments of most systems: digestion, circulation, etc. They have variations in their shape and size. They’re situated between nematodes and arthropods, and people don’t quite know what to do with them. They’re just so unique that way.
Can you tell us a little bit about their mysterious foreign DNA?
Sure! This new discovery by a team at the University of North Carolina in Chapel Hill found that they have up to 18% foreign DNA. Scientists speculate that because tardigrades are such extremophiles, they sometimes experience conditions where the membranes break, and the DNA splits. There are all these different possibilities of how foreign DNA could get into them, more than in other organisms.
I’ve seen a couple of headlines use the term “alien DNA,” but it’s not really alien DNA. I think that was just to get your attention.
Right! The foreign DNA means it’s not water bear DNA; it’s probably from algae they live with or fungi in the droplets of water they float in, but certainly not their own DNA, which is kind of cool.
So let’s get back to the idea of tardigrades in space. Were they attached to the satellite intentionally, or were they just hitching a ride?
They were attached intentionally. There have been some really cool experiments, some of which were inspired by school kids wondering about that question. Because tardigrades are extremophiles, could they survive in outer space? Technically, they are the only creatures known to go into outer space, come back, and retain all the qualities and characteristics of life. That’s a very cool thing to think about. Could they have come from somewhere else? Could they be going to another planet? That really brings to mind a lot of creative thinking about extraterrestrial life.
Thanks so much, Dr. Leman, for joining us today! Where can our viewers find you?
I work at the California Academy of Sciences. You can always find me there; just ask for the tree-climbing lady. I do have a website, www.cancopy.com, and a Twitter handle, which is @canopymeg. I always have a lot of water bear information popping up on those sites. I would love to have young visitors come over to the academy and meet some of my fellow scientists.
I also love octopuses! Check out this video where Trace learns how these creatures change color. Most of their skin can change shape, texture, and color. They have muscles in their skin that will push out these little flaps of skin, so they can look spiky or like a rock or algae.
So what do you think? Are tardigrades cute or hideous? You better think they’re cute! Sound off in the comments below. Don’t forget to hit those like and subscribe buttons and keep coming back so you don’t miss a single episode!
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This version removes any informal language, music cues, and maintains a professional tone while preserving the content.
Tardigrades – Microscopic organisms known for their ability to survive extreme conditions, such as high radiation and temperature. – Tardigrades are fascinating creatures because they can endure environments that would be lethal to most other forms of life.
Extremophiles – Organisms that thrive in extreme environmental conditions, such as high salinity, acidity, or temperature. – Scientists study extremophiles to understand how life can exist in harsh conditions, which might be similar to those on other planets.
DNA – The molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms. – DNA is often referred to as the blueprint of life because it contains all the information needed to build and maintain an organism.
Organisms – Individual living entities that can react to stimuli, reproduce, grow, and maintain homeostasis. – All organisms, from the smallest bacteria to the largest whales, play a role in the ecosystem.
Survive – To continue to live or exist, especially in spite of challenging conditions. – Many plants have adapted to survive in arid environments by storing water in their leaves and stems.
Space – The vast, seemingly infinite expanse that exists beyond the Earth’s atmosphere, where stars, planets, and other celestial bodies are located. – Scientists are exploring the possibility of life in space by studying how organisms can survive in microgravity and radiation.
Conditions – The various factors and circumstances that affect the environment in which an organism lives. – The conditions in the deep ocean, such as high pressure and low light, require unique adaptations from the organisms that live there.
Microscopic – So small that it can only be seen with the aid of a microscope. – Microscopic algae are crucial to aquatic ecosystems because they produce oxygen through photosynthesis.
Algae – Simple, typically aquatic organisms that can perform photosynthesis and are often found in water bodies. – Algae play a vital role in the food chain, serving as a primary food source for many marine animals.
Fungi – A group of spore-producing organisms that feed on organic matter, including molds, yeast, and mushrooms. – Fungi are essential decomposers in ecosystems, breaking down dead organic material and recycling nutrients.
