1900 Air Pollution

Examine this graph from FRONTLINE/NOVA: "What's Up with the Weather?" Web site to see dramatic increases in three greenhouse gases over the last two hundred years.

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.

Amazing Heart Facts

This feature from the NOVA "Cut to the Heart" Web site highlights facts about the heart -- including its size and placement -- and will help you to understand the importance of this wondrous organ in our bodies.

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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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Astronauts in Hard Hats

This media-rich series of interviews from the NOVA Web site explores the unique challenges faced by astronauts doing construction work in outer space.

Atmospheric Carbon Dioxide Levels

Earth is warming because of an increase in greenhouse gases, including carbon dioxide (CO₂). Explore what can be done to slow or stop continued climate change.

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Atmospheric Pressure

Did you know that air has weight? This illustrated essay from the NOVA Web site explores conditions that affect air density and atmospheric pressure.

The Beginnings of the Telescope

This animated essay from the NOVA Web site examines the design of Galileo's refracting telescope and Sir Isaac Newton's reflecting telescope.

Buoyancy Basics

This illustrated demonstration from the NOVA Web site explains the concepts of buoyancy and density by showing what happens when different kinds of wood blocks are dropped in water.

Chernobyl: What Really Happened?

This text excerpted from Richard Rhodes' book, Nuclear Renewal and reprinted on the FRONTLINE Web site examines the causes of the Chernobyl accident.

Chris Schneider: Rethinking Conservation

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

CO₂ Concentrations at Mauna Loa Observatory, Hawaiʻi

This resource, adapted from the Carbon Dioxide Information Analysis Center, provides a graph of monthly average carbon dioxide (CO₂) concentration from 1958 to 2000 at the Mauna Loa Observatory in Hawaiʻi.

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.

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.

Dab of DNA Helps Keep Counterfeiters at Bay

Find out in this USA Today article how DNA sequences can vouch for a souvenir's authenticity.

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.

The Dating Game: Radioactive Carbon

In this media-rich essay from the NOVA Web site, learn about the atomic structure of radioactive carbon and how it can be used to determine the age of organic remains, such as bones and teeth.

Decreasing California Snowpack

Approximately 40 percent of California's surface water supply originates from the snowpack in the Sierra Nevada Mountains. However, climate change is significantly altering this precious water source.

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Demolition Woman

Find out how controlled explosions are used to demolish multi-story buildings in this interview from the NOVA Web site.

Diamonds: The Science Behind the Sparkle

This illustrated essay from the NOVA Web site explains why the atomic structure of a diamond slows down light and produces a sparkle more brilliant than from any other colorless substance.

Discovering Air

Our understanding about the air we breathe has changed dramatically through time. This illustrated timeline from the NOVA Web site tracks the changing thought on air and the creation of the Periodic Table of the Elements.

DNA Fingerprint Photos

These photographs supplied by Genelex Corporation depict actual DNA fingerprints and show the types of information that can be gleaned from them.

DNA Makes History

Read how DNA was used to solve the mystery of the Romanov family's execution. From Human Genetics: Concepts and Applications by Ricki Lewis.

DNA on the Witness Stand

In this article, Dr. Eric Lander of the Human Genome Project comments on the use of DNA as an identification tool -- the theoretical versus the practical results.

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Dr. Jay Giedd: The Adolescent Brain

In this transcript from FRONTLINE: "Inside the Teenage Brain," neuroscientist Dr. Jay Giedd discusses new research on brain development in teenagers.

Einstein: A Timeline of His Life

This illustrated timeline from the NOVA Web site follows Albert Einstein's life, including 1905, his "Miracle Year," during which he developed his Special Theory of Relativity and the equation, E=mc².

Einstein: How Smart Was He?

This essay from the NOVA Web site explores the impact Einstein made on physics and most everything we know about the cosmos.

Evidence for Evolution

In this Evolution WebQuest you will investigate a variety of types of evidence for evolution.

Evolution on Double Time

This excerpt from Evolution: The Triumph of an Idea by Carl Zimmer describes how gene duplication may have been the key to the rapid evolution of the early stages of life on Earth.

Facts About Radiation

This document from the FRONTLINE Web site offers examples of everyday exposure to radiation.

FAQs About Nuclear Power

Nuclear physicist, Dr. Charles Till, answers questions about nuclear power in this interview from the FRONTLINE Web site.

Farallon Islands Map

With this map from QUEST produced by KQED, explore what it is like to live on the rocky remote Farallon Islands for both birds and the scientists who explore them.

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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.

Fission and Reprocessing: How They Work

This video-enhanced document from the FRONTLINE Web site explains how nuclear fission and nuclear reprocessing work.

Forecasting Suitable Habitat for North American Wolverines From the Present to 2100

Learn what plants and animals must do in order to survive significant environmental changes.

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Forensics

Find out how DNA profilers analyze bits of tissue to identify human remains. From NOVA: "Lost on Everest" Web site.

Galileo: His Place in Science

Einstein called Galileo the "father of modern physics." This media-rich essay from the NOVA Web site looks at Galileo's quest to understand the mathematics of motion.

Galileo: Timeline of His Life

This illustrated timeline from the NOVA Web site turns back the clock to the late 1500's to relive the dramatic life of one of the world's most renowned scientists.

Genetic Art

Take a peek at the artistic side of science in this virtual exhibit, featuring work by Eva Sutton, Alexis Rockman and Sidney Harris.

Genetics Case Studies

Wrestle with ethical issues concerning genetic rights and practices from the NOVA: "Cracking the Code of Life" Web site.

Genome Facts

This list from NOVA: "Cracking the Code of Life" Web site provides some of the basic, yet impressive, facts and figures about the Human Genome Project.

Get Close to a Nuclear Fission Reaction!

Learn how scientists regulate a nuclear reactor in this animation-enhanced essay from the FRONTLINE Web site.

Global Warming: Beyond Fossil Fuels

Martin Hoffert, professor of physics at New York University, discusses global warming and alternative energies in this interview from the NOVA/FRONTLINE Web site.

Global Warming: Graphs Tell the Story

Examine graphs from the NOVA/FRONTLINE Web site to see dramatic changes in the temperature of Earth's surface and in the levels of greenhouse gases in the atmosphere.

Global Warming: Graphs Tell the Story

Examine these graphs from the NOVA/ FRONTLINE Web site to see dramatic increases in the temperature of Earth's surface and greenhouse gases in the atmosphere.

Global Weather Machine

In this illustrated essay from NOVA Online, explore the cyclical process of weather creation and the effects of El Niño on the global weather system.

The Greenhouse Effect and Greenhouse Gases

Increasing greenhouse gases are contributing to global warming, which is changing our climate.

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How Big Is the Universe?

In this media-rich essay from the NOVA Web site, astronomer Brent Tully of the University of Hawaiʻi walks you through the latest scientific theories about the size of the universe.

How DNA Evidence Works

In this article by An Meeker-O'Connell, discover how DNA evidence is processed before it goes to court.

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