Enjoy five days' worth of comprehensive daily lesson plans, engaging activity worksheets, graphic organizers and more!

Deep-sea fish adapt to some of the most extreme conditions on Earth. New research analyzing their evolution finds the same mutation across fish species that have evolved on separate timelines — ...

Imagine a world where the boundaries between “fish” and “not-fish” blur, where the ancestors of birds and mammals once swam ...

Imagine a fish that spends more time out of water than in it, a creature that blurs the boundary between land and sea with a ...

It's a world full of organisms with unique adaptations to such a challenging environment. Welcome to the abyss. The viperfish (pictured above) is a fierce predator, with fangs so big that its mouth ...

But once on land, the animals found their limbs a survival advantage there, too. Evolution frequently produces adaptations that come to be useful in the future for a different purpose.

Fish at the other end of Earth ... In each case, evolutionary adaptations allow them to exploit a food niche of ants and termites, but the developments occurred independently.

The infamous box jellyfish developed its frighteningly powerful venom to instantly stun or kill prey, like fish and shrimp, so their struggle to escape wouldn’t damage its delicate tentacles.