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ANDREW BERRY: Evolution by natural selection. This is an idea that has been sought after since the dawn of human thought. And it was a theory that was discovered by two people, and we've...

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The malaria parasite is an ancient organism. It has been with us since before we were human. Famous victims include Alexander the Great Genghis Khan and George, Washington. The malaria lifecy...

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Many years ago,a young man named Giovanni Guasconti left his home in Naples to study in northern Italy.He rented a small room on the top floor of a dark and ancient palace.Long ago, the building had b...

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[NARRATOR:] Mosquitoes are usually vegetarian, preferring to drink nectar, fruit juices, and honeydew. Only a pregnant mosquito will bite humans, seeking nutrients from blood to nourish he...

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SEAN CARROLL: For tens of thousands of years, much of North America lay buried under ice up to a mile thick. Then the massive ice sheets receded. In what is now Alaska, ocean bound stream...

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So the basic concept is that heat inside the Earth drives motions. We have convection currents, through which heat is dissipated from the interior of the Earth. Those convection current...

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TYLER LYSON: Even though I've collected thousands and thousands of dinosaur bones and other fossils, every fossil that I find, it's just quite a thrill because you're the first person ...

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Earth’s temperature is affected by a process called the greenhouse effect, which is how the atmosphere keeps our planet’s surface warm. This process begins with energy from the sun, which is m...