As wildlife tourism grows, scientists are asking a bigger question: can we bring people closer to nature without reshaping the ecosystems they came to see?

PORTLAND, Maine (AP) — Sharks are the most feared predators in the sea, and their survival hinges on fearsome teeth that regrow throughout their lives. But changes in the ocean’s chemistry could put ...

You probably don’t think much about teeth until a dentist brings them up. But across the animal kingdom, tooth counts can get wild fast.