Subtopic: Processes of Evolution

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.

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.

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

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."

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.

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 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."

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.

Evolving Ideas: Why Does Evolution Matter Now?
In this video from Evolution, an exploration of multi-drug resistant tuberculosis in the Russian prison system highlights one reason it is important to understand evolution.

Fish with Fingers
In this video segment from Evolution: "Great Transformations," paleontologist Jenny Clack explains that vertebrates evolved fingers before they invaded land.

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.

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.

Genetic Variation
This video segment from NOVA: "Cracking the Code of Life" explores the genetic similarities and differences among organisms.

How Evolution Works
Students learn about natural selection by discussing the evolution of the eye, genetic variation, adaptation, sexual selection, and the Galapagos finches.

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.

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.

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."

Microbe Clock
In this Evolution Web feature, learn how mutation and fast reproductive rates can allow deadly microbes to outpace medical breakthroughs.

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.

A Mutation Story
This video segment describes the role of the sickle cell gene in natural selection. Footage courtesy of the PBS series Secret of Life: "Accidents of Creation."

Permian-Triassic Extinction
In this video segment from Evolution: "Extinction!", geologist Peter Ward discusses evidence for a Permian-Triassic mass extinction.

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

Sex and the Single Guppy
Play in our streams and see how exhibitionism has an evolutionary payoff in this Evolution simulation of Endler's experiment.

Tale of the Peacock
The peacock provides a classic example of sexual selection, the force behind nature's extravagances. From Evolution: "Why Sex?"

Ted Daeschler and Neil Shubin: Early Tetrapod Fossils
In this transcript of an interview filmed for Evolution: "Great Transformations," Ted Daeschler and Neil Shubin describe the discovery and significance of some of their key fossil finds.

Toxic Newts
The father and son team of Brodie and Brodie track down the predator able to stomach a mysteriously hyper-toxic newt, an example of an evolutionary arms race in action. From Evolution: "Evolutionary Arms Race."

Transitional Tetrapod Fossil
In this video segment from NOVA: "Judgment Day: Intelligent Design on Trial," learn about the discovery of a well-preserved transitional fossil and how such transitional fossils support the theory of evolution.

Whales in the Making
This graphic from Evolution, traces the evolution of whales from land-dwelling mammals to the aquatic creatures we know today.