This discussion explores how artificial boundaries can decrease mate choice, with a specific example of highways limiting mate choice for bighorn sheep.
Lesson Plan, Educator Guide
This worksheet prepares students to compare this historic food web of the Chesapeake Bay to the food web of the present day.
Some scientists believe the fate of humankind was changed when humans first began to tame the wild horse. Learn more about how horses have shaped our world.
Not all dinosaurs were enormous like the 84-foot-long, 30-ton Apatosaurus. TheCompsognathus, for example, approximated an eight-pound chicken. Size up two others.
Did you know that squamates have a third eye? Or that the Gila Monster and the Bearded Lizard are the only two known venomous lizards? Discover more interesting facts about squamates.
It's not surprising that the larger the world's population grows, the more fresh water we consume. But what is surprising is just how much of this precious commodity we've depleted in recent years.
With unblinking eyes the size of soccer balls and a body that can stretch the length of a bowling alley, the giant squid has long fascinated humans. Investigate the largest invertebrate on Earth.
Did you know that the world's deserts keep expanding each year? Or that islands have the highest animal extinction rate—75 percent? Take a closer look at the major habitats found on Earth.
Travel to the Galápagos Islands and follow in Charles Darwin’s footsteps with this interactive investigation. You’ll have the chance to collect clues as you investigate the islands’ species.
Gravity helps form the stars and planets and helps keep them in orbit. Yet, it can also cause these objects to collide. Explore the many ways gravity shapes—and reshapes—the universe.
More than likely with a good guess you could detect a heart-shaped leaf from one that's oval or narrow. But do you know how to recognize a leaf that has a lobed or divided shape? Learn how.
Go beyond petals and leaves! Learn how to identify a flower's stamen, anther, filament, stigma, and more with this illustrated look at the parts of a flower.
What can scientists know about a creature by examining its bones? And what can they only guess at? Show students with this hands-on activity.
Unicorns and dragons and Sasquatch, oh my! Continue the investigation of fantastic creatures with this mythological menagerie of books.
For centuries, people around the world have told stories about dragons, unicorns, and mermaids. See what may have inspired people to believe in these legends.