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.

Function of Fever

Fevers are a sign of infection, but they may also be part of the cure. This drawing illustrates Matthew Kluger's lizard study, which supports the notion that fever can be beneficial.

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Genetic Drift and the Founder Effect

This image of polydactyly illustrates one symptom of Ellis-van Creveld syndrome, which is commonly found in the Amish. Ellis-van Creveld is one example of the founder effect and genetic drift.

Laetoli Trackways Diagram

View a diagram of the hominid footprints that archaeologist Mary Leakey's team found at Laetoli in Tanzania.

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.

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.

Tetrapod Limbs

This illustration from Evolution by Monroe W. Strickberger shows the remarkable similarities between the bones in the forelimbs of various tetrapods, all of whose limbs serve very different functions.

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