Hi there! I’m Emily from MinuteEarth, and today we’re diving into the fascinating world of size in nature. We’ll explore why some things are huge, others are tiny, and why size is important in the natural world. Let’s get started with four intriguing stories!
First, let’s talk about the biggest living things on our planet. You might think the blue whale, which weighs over 150 tons, is the largest. It’s true that blue whales are the biggest animals ever, even bigger than the largest dinosaurs. But when it comes to the biggest living organism, it depends on how you define “biggest.”
The tallest living thing is a California redwood tree named “Hyperion,” which stands at a whopping 115 meters tall, taller than the Statue of Liberty! But the most extensive organism is a massive fungus in Oregon that covers about 2,385 acres. This fungus mostly lives underground, with only clusters of honey mushrooms visible above ground. It’s like if apple trees grew underground, and only the apples popped up!
When it comes to weight, the heaviest organism is a quaking aspen called “Pando.” It weighs over 6,000 tons, which is like 40 blue whales! Pando looks like a forest of regular trees, but genetic tests show it’s actually one giant organism. All 47,000 trees are connected by a single root system, making them one big family.
Animals don’t just become gigantic overnight. Something special has to happen for them to grow so large. Most animals stay about the same size over time, but sometimes extraordinary events allow them to grow bigger.
For example, insects and other arthropods are small because they breathe through their exoskeletons, and oxygen can only travel so far. About 300 million years ago, Earth’s oxygen levels increased, allowing insects to grow much larger. Imagine dragonflies the size of eagles!
Dinosaurs grew large without any outside help, but they faced a limit due to the “square-cube law.” As animals grow, their weight increases faster than their strength. Dinosaurs found a way around this by developing air pockets in their skeletons, allowing them to grow larger without getting too heavy.
Some animals returned to the water, where buoyancy helped them grow even bigger. A few million years ago, changes in ocean currents brought nutrients to the surface, leading to an abundance of food for blue whales. This allowed them to become the largest animals ever.
In the ocean, life comes in all sizes, and it turns out we should be eating more of the small stuff. When fishing, it’s important to let big fish escape. Large fish produce the most successful offspring, so removing them can harm the population’s ability to replenish.
There’s a new idea called “balanced harvesting” that suggests catching a smaller number of fish across different sizes to maintain a balanced population. This approach could help ensure a sustainable future for fish populations.
Have you ever wondered how many water molecules it takes to make a drop? Inside every raindrop is a tiny impurity, like a speck of dust, that helps water vapor condense into droplets. Water molecules stick together but also break apart due to heat. When the air cools to the “dew point,” clusters of water molecules can grow into droplets.
If a cluster is too small, it might lose molecules instead of gaining them. Luckily, tiny particles in the atmosphere help clusters reach the critical size needed for droplet formation. These particles surrounded by water make life possible on Earth.
Thanks for joining me on this journey through the science of size!
Research and create a chart comparing the sizes of the largest organisms discussed in the article: the blue whale, Hyperion, the Oregon fungus, and Pando. Use visuals to represent their size differences. This will help you understand the concept of size in nature better.
Conduct a simple experiment to understand the square-cube law. Use clay or playdough to create models of animals at different sizes. Measure their surface area and volume to see how size affects weight and strength. This will give you insight into why animals can’t grow indefinitely large.
Research how oxygen levels in Earth’s history affected the size of insects. Create a timeline showing the changes in oxygen levels and the corresponding sizes of insects. This will help you grasp the relationship between environmental factors and animal size.
Imagine you are a marine biologist tasked with creating a balanced harvesting plan. Use the concept of balanced harvesting to propose a sustainable fishing strategy that maintains fish populations. Present your plan to the class and discuss its potential impact on marine ecosystems.
Create a model to demonstrate how water droplets form around impurities in the atmosphere. Use materials like cotton balls and beads to represent water molecules and impurities. This hands-on activity will help you visualize the process of droplet formation and its importance in nature.
Sure! Here’s a sanitized version of the transcript:
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Hi! I’m Emily from MinuteEarth. Today, we have four short stories about the science of size, exploring why big things are big, small things are small, and how size matters in nature.
First up, a quest for the biggest organism on the planet. Blue whales are the largest animals ever to exist on Earth, weighing upwards of 150 tons, more than the largest dinosaurs. However, the blue whale is not the biggest living thing. The title depends on how you define “biggest.” The tallest living organism may be a California redwood nicknamed “Hyperion,” which stands at an impressive 115 meters, taller than the Statue of Liberty. The most extensive organism is a very old humongous fungus that covers about 2,385 acres in a national forest in Oregon. At the base of trees, clusters of honey mushrooms appear, which are the fruiting bodies of the fungus that lives mostly out of sight. Imagine if apple trees grew underground and only the apples were visible; that’s similar to how this fungus operates, spreading its mycelia through soil and tree roots, sometimes attacking them to steal nutrients.
If we consider the heaviest organism, that title goes to a quaking aspen named “Pando,” which weighs over 6,000 tons, equivalent to 40 blue whales. If you visit Fish Lake National Forest, you won’t see a giant tree trunk; instead, you’ll find a forest of regular-sized trees. Genetic testing has revealed that this stand of aspen, covering 106 acres, is actually a single clonal organism that originated from one seed long ago. Its roots send up shoots that grow into what appear to be individual trees. Since all 47,000 trees are part of the same organism, the forest behaves unusually, transitioning simultaneously from winter to spring and using its extensive root network to distribute water and nutrients.
When considering water in the weight of these giant organisms, the humongous fungus might weigh more than Pando, but foresters typically focus on the dry mass produced during growth. Since fungi are mostly water, Pando takes the win. It’s likely that some underground connections have been severed over time, meaning these giants are probably made up of smaller, genetically identical patches. Due to the extensive testing required to confirm “biggest” claims, the fungus and aspen can only claim to be the largest living organisms ever found. There may be even bigger organisms waiting to be discovered.
Animals don’t just become gigantic overnight; something unusual must occur for them to grow to such sizes. Animals come in various sizes, but typically, each type remains roughly the same size over evolutionary time. Occasionally, something extraordinary happens that allows an animal to grow significantly larger. For example, insects and other arthropods have small bodies partly because they breathe through their exoskeletons, and the available oxygen can only diffuse so far. About 300 million years ago, Earth’s atmospheric oxygen levels spiked, allowing arthropods to grow much larger, leading to mega-bugs like dragonflies the size of eagles.
Dinosaurs, on the other hand, grew large without external help but eventually hit a limit due to the “square-cube law.” As animals grow, their weight increases faster than their strength, which is based on cross-sectional area. Fossil evidence suggests that dinosaurs were nearing a size limit when they discovered a breakthrough: a system of air pockets and sacs in their skeletons that allowed them to grow larger without becoming heavier. Eventually, some land animals returned to the water, buoyed by it, which enabled them to grow almost twice as large as the biggest fish.
A few million years ago, changing ocean currents brought nutrients up from the depths, fueling phytoplankton blooms that attracted large concentrations of zooplankton. With this new nutrient-rich diet, blue whales tripled in size, becoming the largest animals to have ever lived.
In the ocean, life comes in all sizes, and it turns out we humans should be eating more of the small stuff. Anyone who goes fishing likely has a story about the one that got away. It’s important that big fish escape, both for the fish population and fishermen. Laws often protect juvenile fish, allowing them to grow and reproduce before being caught. However, this approach doesn’t always work. Large individuals produce the most successful offspring, and by removing them, we reduce the population’s ability to replenish itself. Additionally, if only the largest fish are removed, smaller fish are more likely to survive and reproduce, leading to a population of smaller fish over time. This size-selective fishing has resulted in a significant decrease in the body mass of large commercial fish over the last 40 years.
There’s a new idea called “balanced harvesting” that aims to address this issue. Instead of only catching the largest fish, fishermen would catch a smaller number across a wider range of sizes, maintaining a balanced population. However, changing established practices can be challenging, and it’s essential to let some of the big ones get away to ensure a sustainable future for fish populations.
Now, let’s talk about tiny water. How many water molecules does it take to make a drop? Inside every raindrop is a tiny impurity—a touch of salt, a speck of soot—that is crucial for the raindrop’s existence. Without these microscopic particles, water vapor can’t condense into droplets. Water molecules tend to cling to each other, but they also break apart due to heat energy. Only when the air cools past a certain point, called the “dew point,” do clusters of water molecules grow into droplets. However, if a cluster is too small, it has a higher chance of losing molecules than gaining them, making it difficult to reach the critical size needed for droplet formation.
Fortunately, clusters can start at that critical size by condensing onto tiny particles in the atmosphere, allowing them to grow into droplets in a rain cloud. Ultimately, it’s these tiny particles surrounded by water that make life possible on our planet.
Thank you for watching!
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This version maintains the essence of the original transcript while removing any informal language and ensuring clarity.
Size – The physical dimensions or magnitude of an object or organism. – The size of an elephant is much larger than that of a mouse.
Organisms – Living things that have the ability to act or function independently. – Bacteria and fungi are examples of organisms that play important roles in ecosystems.
Animals – Multicellular organisms that are typically capable of movement and responsive to their environment. – Lions, tigers, and bears are all animals that live in the wild.
Oxygen – A chemical element that is essential for most forms of life on Earth, used in respiration. – Plants release oxygen into the air during the process of photosynthesis.
Insects – Small arthropods with a segmented body, six legs, and usually wings. – Bees are insects that play a crucial role in pollinating flowers.
Fish – Aquatic animals that have gills and fins, and are typically covered with scales. – Salmon are fish that migrate upstream to spawn in freshwater rivers.
Population – A group of individuals of the same species living in a specific area. – The population of deer in the forest has increased over the past decade.
Water – A transparent, tasteless, odorless, and nearly colorless chemical substance, essential for life. – Water is vital for all living organisms to survive and thrive.
Molecules – Groups of atoms bonded together, representing the smallest fundamental unit of a chemical compound. – Water molecules consist of two hydrogen atoms and one oxygen atom.
Droplets – Small drops of liquid, often formed by condensation. – Tiny droplets of water formed on the leaves after the morning dew.
