Tiktaalik: A Fish Out of Water

In this lesson designed to enhance literacy skills, students learn that transitional fossils provide scientists with evidence to establish how major animal groups are related to one another.

Adaptive Radiation: Darwin's Finches

Finches on the Galapagos Islands have evolved to exploit almost every possible niche. This diagram shows the range of food sources available on the island and the different beak shapes adapted to exploit each of them.

The Advantage of Sex

Why did sex evolve? The likely answers, in this essay for the Evolution Web site by science journalist Matt Ridley, may surprise you.

Allopatric Speciation

These images from the Smithsonian Institution depict Nancy Knowlton's work with snapping shrimp in Panama. Knowlton found that the closing of the isthmus -- dividing the Pacific Ocean from the Caribbean -- resulted in new species of shrimp.

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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Animal Body Plans: Homeobox Genes

The homeobox genes that define the basic body plan of mice and fruit flies are illustrated in this graphic from The Human Evolution Coloring Book by Adrienne Zihlman. The accompanying article describes how these genes act as "molecular architects" in all animal species.

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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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Chris Schneider: Rethinking Conservation

In this interview filmed for Evolution: "Darwin's Dangerous Idea," biologist Chris Schneider discusses the relationship between conservation and speciation.

Climate and Human Evolution

In this video segment adapted from NOVA: "Becoming Human," learn how the analysis of rock layers and ocean sediments supports the theory that rapid climate change may have jump-started human evolution two million years ago.

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Co-Evolution

Students explore different types of symbiotic relationships that exist between species.

The Common Genetic Code

Paul Nurse describes his research that showed that humans share some genes with organisms as different from us as simple brewer's yeast. Footage from Secret of Life: "Immortal Thread."

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Complex Relations

In this text excerpted from chapter 3, "Struggle for Existence," of Charles Darwin's On the Origin of Species, Darwin draws on firsthand and historical information for his observations about evolution.

Convergence: Marsupials and Placentals

This graphic illustrates some of the marsupial mammals in Australia and placental mammals in North America. Even though they are not closely related, these mammals look alike because they have adapted to similar ecological roles. From The Human Evolution Coloring Book by by Adrienne Zihlman.

Coral Reef Connections

Dive in and explore what makes this beautiful world so fragile. In this Evolution Web feature, discover how coevolution has shaped the ecological relationships among reef creatures.

Engineering Biofuels

In this video segment adapted from KQED's QUEST, find out how synthetic biologists use the techniques of metabolic engineering and directed evolution to make more effective biofuels.

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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."

Evolution of Camouflage

This video segment from Evolution: "Darwin's Dangerous Idea" illustrates the remarkable camouflage of a praying mantis against its leafy backdrop.

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Evolution of the Eye

Zoologist Dan-Erik Nilsson demonstrates how the complex human eye could have evolved from simple light-sensitive cells. From Evolution: "Darwin's Dangerous Idea."

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Evolution on Double Time

This excerpt from Evolution: The Triumph of an Idea by Carl Zimmer describes how gene duplication may have been the key to the rapid evolution of the early stages of life on Earth.

Evolving Ideas: How Does Evolution Really Work?

The process of evolution through natural selection is the focus of this video segment from Evolution, which presents a field study of hummingbird speciation in Ecuador.

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