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.

All in the Family

In this Evolution Web feature, test your skills at judging who's who on the tree of life while you learn about the tools and methods of cladistics.

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.

American Chestnut Tree

This annotated slideshow adapted from KET's Electronic Field Trip to the Forest illustrates how blight decimated the American chestnut tree and the methods scientists use to identify and pollinate the remaining trees to create blight-resistant trees.

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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Animal Defenses

In nature, survival is the name of the game. This video segment explores the world of animal defense and shows that predators don't always have the upper hand.

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Are We Alone?

This video segment adapted from NOVA features a variety of scientific perspectives on the age old question, "Are we alone in the universe?" Animations make vivid the improbability that we could intercept a radio wave signaling extra terrestrial intelligence.

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Becoming a Fossil

This video segment describes how the Australopithecus afarensis skeleton known as Lucy could have been fossilized. Footage courtesy of NOVA: "In Search of Human Origins."

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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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The Birds and the Beaks

This Nature lesson explores different adaptations and variations in birds. It focuses on bird beaks, migratory patterns, and the ability of birds to co-exist with humans.

Bones of Contention

This interactive activity from NOVA invites you to do the work of scientists and use a database to classify actual fossil records of human ancestors and related species.

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.

Carnivorous Plants of Cartwheel Bay

In this video segment from NatureScene, explore Cartwheel Bay, a wetland in South Carolina, and learn about the variety of carnivorous plants native to this unique landform.

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Caves: Extreme Conditions for Life

This video segment adapted from NOVA raises the provocative idea that if life can exist in the most extreme environments on Earth — such as in dark, toxic caves — then perhaps living things can also survive in harsh environments on other planets.

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Charles Darwin

Students learn about Charles Darwin -- his personal history, his strengths as an observer and independent thinker, and how he developed the theory of evolution.

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.