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.

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.

Accessibility features: Long Description

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."

Accessibility features: Caption

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.

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.

Accessibility features: Caption

Finch Beak Data Sheet

This graphic from Ecology and Evolution of Darwin's Finches by Peter Grant presents data from the Galapagos Islands, showing that a severe drought put selective pressure on the population of Darwin's finches and resulted in a change in the average beak size in the next generation.

Floral Arrangements

Explore a few of the ways plants pollinate each other in this video segment from Sexual Encounters of a Floral Kind.

Accessibility features: Audio Description, Caption, Transcript

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.

Accessibility features: Caption

Genetically Engineering the Avian Flu

In this video segment adapted from NOVA scienceNOW, learn about a radical biotechnology experiment aimed at figuring out how to stop the avian flu virus.

Accessibility features: Caption

Geneticist Pardis Sabeti

In this video profile adapted from NOVA scienceNOW, learn about geneticist and rock musician Pardis Sabeti, whose innovative insights into natural selection demonstrated how beneficial mutations spread quickly through a population.

Accessibility features: Caption

Human Chromosome 2

In this video segment adapted from NOVA: "Judgment Day: Intelligent Design on Trial," learn how modern genetics and molecular biology offer compelling support for evolution. The video features an interview with biologist Ken Miller.

Accessibility features: Caption

Investigating Neanderthals

This video excerpt from NOVA scienceNOW looks at how head shapes of Neanderthals and modern humans differ.

Accessibility features: Caption, Transcript

Killer Microbe

Learn how biotechnology is used to analyze the evolution of a formerly harmless bacterium into a highly drug-resistant and lethal pathogen in this video segment adapted from NOVA scienceNOW.

Accessibility features: Caption

Leafy Spurge

This video segment from Evolution: "Extinction!" shows how biological control is successfully combating North Dakota's infestation of leafy spurge, a non-native plant.

Accessibility features: Caption

Masters of Disguise

In the face of danger, what's a spineless animal to do? This video segment introduces the concept of camouflage -- how animals achieve it and how this form of disguise benefits both predators and prey. Footage from NOVA: "Animal Impostors."

Accessibility features: Audio Description, Caption, Transcript

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.

Molecular Clocks: Proteins That Evolve at Different Rates

From The Human Evolution Coloring Book by Adrienne Zihlman, four different proteins from humans and horses are compared in this graphic and article, and the reasons each protein evolves at its own characteristic rate are discussed. Each protein is useful for measuring evolutionary change over a different time scale.

Accessibility features: Long Description

The Reproductive Role of Flowers

In this video segment adapted from NOVA, learn about the critical role of flowers in seed plant reproductive biology.

Accessibility features: Caption

Saving the World’s Potatoes

This audio segment from PRI's The World Science Podcast explores the extraordinary variety of potatoes native to the Andes in South America, and the current mission to protect this biodiversity.

Shape of Trees: The Frustration Principle

This series of images shows the work of biologist Karl Niklas on the adaptations and evolution of plants. From The Evolutionary Biology of Plants.