Ancient Farmers of the Amazon

This video segment from Evolution: "Evolutionary Arms Race" tells the story of the leafcutter ant and the fungus it farms -- an example of mutually beneficial symbiosis.

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Arctic Tundra

This video segment from Wild Europe: "Wild Arctic" explores the struggle for survival in one of Earth's most extreme environments.

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Biological Invaders

This video segment from Evolution: "Extinction!" shows the impact of invasive species on native ecosystems.

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Build-a-Fish

In this interactive activity from Shedd Aquarium, build a fish and then release it into the reef to search for food and evade predators. Try different combinations and observe how each kind of fish has unique adaptations that help it survive in its habitat.

Desert Biome

This video segment from NOVA: "A Desert Place" describes the physical characteristics and organisms that define the desert biome.

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Energy Flow in the Coral Reef Ecosystem

This video segment, adapted from NOVA, describes the energy flow in a coral reef, including its food web.

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E. O. Wilson: Ants and Ecosystems

This segment is from an interview with ant specialist and biologist E.O. Wilson, filmed for Evolution: "Evolutionary Arms Race."

Frozen Frogs

This video segment adapted from NOVA scienceNOW shows how the common wood frog freezes solid every winter, an adaptation that allows the organism to survive the cold winter.

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Hummingbird Species in the Transitional Zones

This video segment from Evolution: "Darwin's Dangerous Idea" shows biologists Chris Schneider and Tom Smith studying hummingbirds and other animals in Ecuador. Their research is investigating the processes by which new species are formed.

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Is Love in Our DNA?

Did evolution shape your taste in a mate? Take our interactive poll from Evolution.

Isolating Mechanisms: Lacewing Songs

Hear the different songs of three lacewing flies, which serve as reproductive isolating mechanisms between species and determine mate choice. Lacewing audio song from Charles Henry.

The Kemps Ridley Sea Turtle

This video adapted from Texas Parks and Wildlife Department describes how humans are helping restore safe nesting grounds for the critically endangered Kemp's ridley sea turtle to ensure its successful repopulation.

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Mimicry: The Orchid and the Bee

In this photograph from Oxford Scientific Films, a horned bee attempts to mate with an Ophrys orchid, which has evolved to resemble a female bee.

Mouse Party

In this interactive activity from The University of Utah, examine the molecular mechanisms that affect the brains of mice on drugs. Learn how different drugs create different responses in the brain and alter the natural state of a mouse.

A Night in the Coral Reef

Coral reefs are often portrayed as brightly lit, bustling underwater marvels full of colorful creatures. This video segment, adapted from NOVA, paints a different picture as it explores the nocturnal behavior of organisms in the reef.

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Nihoa Island

This video segment adapted from the NOW-RAMP 2002 Expedition documents a research expedition to Nihoa Island. It showcases Nihoa's unique birds and plants, the threat posed by invading grasshoppers, and restoration efforts.

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Penguin Response to Climate Change

Find out how climate change is affecting Antarctic Adélie penguins and their ecosystem in this video segment adapted from Lloyd Fales and Sweetspot Pictures, Inc.

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Polar Bears and Climate Change

In this video from the World Wildlife Fund, learn how rising temperatures in the southern Arctic could lead to polar bear extinction.

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The Red Queen

An example of the Red Queen hypothesis, the sexual population of Mexican Poeciliid fish are able to keep up with a changing environment, while the asexual populations are not as successful. From Evolution: "Why Sex?"

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Riddle of the Bones

In this Evolution Web feature, piece together clues to how one of our early ancestors looked as you examine images from four significant fossil finds of Australopithecus afarensis.