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.

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.

Accessibility features: Caption

Biological Invaders

This video segment from Evolution: "Extinction!" shows the impact of invasive species on native ecosystems.

Accessibility features: Caption

Bt Corn

This video segment from FRONTLINE/NOVA: "Harvest of Fear" looks at corn that has been genetically modified to resist one insect pest, and the multiple concerns it raises.

Accessibility features: Caption

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 Texas

In this video adapted from Texas Parks and Wildlife Department, learn about carnivorous plants that act as both producers and consumers in an ecosystem. See sundews and blatterworts capture and digest insects.

Accessibility features: Caption

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.

Accessibility features: Audio Description, Caption

Chris Schneider: Rethinking Conservation

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

Classical vs. Transgenic Breeding

This video segment from FRONTLINE/NOVA: "Harvest of Fear" explains that genetic engineering and classical breeding both alter the genetic makeup of crop plants.

Accessibility features: Caption

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

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.

Continental Divide: The Breakup of Pangaea

Examine geological evidence found in fossils, rock deposits, and ancient mountains that supports the theory of continental drift in this interactive activity adapted from the Exploratorium.

Darwin: Reluctant Rebel

This video segment from Evolution: "Darwin's Dangerous Idea," together with interviews with Daniel Dennett and James Moore, depicts Darwin struggling with publicizing his revolutionary theory.

Accessibility features: Caption

Darwin's Diary

Delve into the private thoughts of a reluctant revolutionary in this Evolution Web feature.

Darwin's Letters: Collecting Evidence

This group of letters is a sample of the extensive correspondence Darwin carried on with a wide group of friends and colleagues as he collected evidence to support his theory of evolution by natural selection. From Charles Darwin's Letters: A Selection 1825-1859.

Darwin's Letters to Lyell

In this letter written to his friend and mentor Charles Lyell less than three weeks after the publication of On the Origin of Species, Darwin describes the reaction of the great anatomist Richard Owen to his theory. From Charles Darwin's Letters: A Selection 1825-1859.

Deep Sea Vents and Life's Origins

Deep-sea vents are home to strange, luminescent life forms that thrive through chemosynthesis. This video segment from NOVA: "Volcanoes of the Deep" hypothesizes life's beginnings in this extreme environment.

Accessibility features: Audio Description, Caption, Transcript

Deep Time

Explore 4 billion years of life on Earth and discover major transformations, geological changes, and extinction episodes in this Evolution Web feature.