The 5 Times Life on Earth Almost Ended

Kurzgesagt – In a Nutshell • 2:50 minutes • YouTube

🤖 AI-Generated Summary:

The Five Mass Extinction Events That Shaped Life on Earth

Life on Earth is a constantly evolving story, marked by periods of flourishing biodiversity and devastating mass extinctions. Throughout our planet’s history, 99% of all species that ever lived have vanished. These losses were primarily due to five major mass extinction events, each dramatically reshaping life and ecosystems. Let’s explore these pivotal moments in Earth’s history and what they reveal about the fragility and resilience of life.

1. The Earliest Extinction – The Ordovician Event (Around 445 Million Years Ago)

The first major extinction event occurred when most life was underwater. Approximately 90% of marine species, including lampshells, moss animals, and early arthropods, disappeared. The primary cause was likely a global cooling phase combined with a significant drop in ocean levels. This environmental shift disrupted marine habitats and food chains, leading to widespread species loss.

2. The Algae Annihilation – The Devonian Extinction (Around 360 Million Years Ago)

The second major die-off was somewhat paradoxical. It was triggered by an explosion of algae growth, which depleted oxygen levels in the oceans. This phenomenon was linked to the evolution of trees and flowering plants with roots that enriched soils and washed nutrients into the seas. The resulting oxygen depletion caused suffocation of many marine animals and the collapse of food chains. Around 75% of species, including the massive Dunlosta, were wiped out.

3. The Great Dying – The Permian Extinction (Around 250 Million Years Ago)

Known as the most severe extinction event, the Permian extinction eradicated more than 90% of all species. Countless insects, fin reptiles, sea urchins, starfishes, and corals vanished. This catastrophe was likely caused by massive volcanic eruptions, which released greenhouse gases and led to global warming. The resulting environmental changes made vast areas uninhabitable, fundamentally altering life on Earth.

4. The Dawn of the Dinosaurs – The Triassic Extinction (Around 200 Million Years Ago)

Around 200 million years ago, another wave of global warming caused the Triassic extinction, wiping out about 80% of species, including many marine invertebrates and large reptiles like phytosaurs. However, this extinction paved the way for the rise of the dinosaurs, who became the dominant terrestrial creatures for the next 135 million years.

5. The Dinosaur Demise – The Cretaceous Extinction (Around 66 Million Years Ago)

The most famous extinction event ended the reign of the dinosaurs. Triggered by a massive asteroid impact, this event caused fires, earthquakes, and volcanic activity, devastating life within a 1,500 km radius. Approximately 75% of all species went extinct, including non-avian dinosaurs. This extinction cleared the path for mammals and eventually humans to flourish.

Are We Facing a Sixth Mass Extinction?

Today, scientists warn that we might be on the brink of another mass extinction—this time caused by humans. Species are disappearing at rates 100 to 1,000 times faster than the natural background rate, driven by habitat destruction, pollution, climate change, and overexploitation. While the planet itself will endure, the loss of biodiversity has profound consequences for ecosystems and humanity.

Conclusion

The history of life on Earth is punctuated by dramatic extinction events that remind us of nature’s power and vulnerability. Understanding these past extinctions helps us appreciate the delicate balance that sustains life and highlights the urgent need for responsible stewardship of our planet. After all, the next extinction event could very well be ours—making it crucial to act now to protect the diversity of life that remains.

📝 Transcript (64 entries):

The circle of life always continues. 99% of the species that ever lived on Earth have died out again since. Let's have a look at the five mass extinction events that caused most of that carnage. One, the earliest extinction. Around 445 million years ago, most species lived underwater. The order extinction killed off almost 90% of them like many species of lampshells, moss animals, and anthropods. The reason was probably the onset of a global cooling phase and drops in ocean levels. Two, the algae annihilation.

The next drop in species diversity might actually have been caused by a growth boost 360 million years ago. In the Devonian extinction, algae populations suddenly ran rampant on huge scales and depleted oxygen levels in the oceans.

This might have been due to the fact that the evolution of trees and flowers with roots made the soils more nutrient-rich. Marine animals suffocated and food chains were messed up. Around 75% of all species like the massive dunlostas died. Three, the biggest breakdown. Fast forward to 250 million years ago to the perian extinction, also called the great dying. It killed off more than 90% of all species among the many insects, fin reptiles, sea urchins, starfishes, and most of all corals. This extinction was likely caused by a huge outburst of volcanic activity. It led to global warming, changing living conditions over vast areas.

Four, the dawn of the dinosaurs. Another surge of global warming 200 million years ago heralded in the Triacic extinction. Bummer for about 80% of species, from marine invertebrates to large reptiles like phytosaurs, but a huge win for everyone's prehistoric favorite, dinosaurs. This extinction likely allowed them to become the dominant inhabitants of Earth. Five, the dinosaur demise. Easy come, easy go. The next extinction then wiped dinosaurs off

the planet around 66 million years ago. The Cretaceous extinction was caused by an asteroid hitting Earth. That impact burned everything in a 1,500 km radius and triggered earthquakes and volcanic activity. Around 75% of all species died out. And since then, right now, we seem to be on the verge of the next mass extinction. And this time, we humans are the cause. Today, species are going extinct between 100 to 1,000 times faster than expected. But who knows, maybe the next extinction event will be ours. Too bad for us, but the planet won't care much.

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