Evolution

Evolution is occurring slowly and constantly. All life evolved from the sea millions of years ago and ocean species have made adaptations over time to life underwater.

LATEST POSTS

DIVE DEEPER

Did Whale Evolution Go Backwards?

Whales swim, but their ancestors walked. Whales are mammals (like us) whose ancestors lived on land. Life probably began in...

Spirals in Time: A Walk at the Seashore

When I set out to write a book about mollusks (called Spirals in Time ), I wasn't quite prepared for just how many animals I would get to know. There are somewhere between 100,000...

In the Arctic, the Times, They Are a-Changin: You Can Pitch in to Understand How

This 1874 illustration of California gray whales ( Eschrichtius robustus ) shows a group of individuals at the edge of their modern day range in the North Pacific Ocean, blocked from traveling further east...
Riftia tubeworm (Riftia pachyptila) colonies near hot spring.

The Microbes That Keep Hydrothermal Vents Pumping

These tubeworm colonies grow where hot, mineral-laden water flows out of the seafloor in undersea hot springs. Credit: ©2003 MBARI By Lyndsy Gazda & the Ocean Portal Team Life is typically sparse on the...

Meet the Tiny Bacteria That Give Anglerfishes Their Spooky Glow

Descend two hundred meters (about 656 feet) below the surface and the ocean is reduced to total darkness. Creatures that live beyond the Twilight Zone spend their lives almost entirely in a near-limitless black...
Aquatic Locomotion of a Sea Lion

How Do Sea Lions Swim?

Sea lions generate thrust, or forward propulsion, by bringing their fore-flippers together in big sweeping motions called “claps.” When a sea lion “claps,” it stretches its flippers out to the sides and sweeps them...
Ocean Portal Logo

With Every Breath You Take, Thank the Ocean

Kelps are large, brown algae that grow along coasts around the world, especially in cooler regions. Credit: George Cathcart By Kalila Morsink When was the last time you thought about your breathing? Take a...
A narwhal breaches the surface, its tusk pointed to the sky

Why a Tusk? The real-life unicorns of the sea and the tusks that make them famous

A narwhal breaching the water's surface, his tusk points to the sky. Male narwhals will sometimes cross their tusks, a behavior called "tusking". Credit: Glenn Williams In the frigid Arctic Ocean , a mysterious...
Common cuttlefish

So You Think You're Smarter Than a Cephalopod?

Like other cephalopods, the common cuttlefish ( Sepia officials Linnaeus, 1758) possesses serious brain power. Credit: Hans Hillewaert, WoRMS for SMEBD The blanket octopus can rip a poisonous tentacle from a Portuguese man-o-war and...
An adult and juvenile killer whale frolic in the water.

Menopausal Moms: A Mammal Mystery

Killer whales ( Orcinus orca ) have something in common with humans: early menopause. Credit: Robert L. Pitman, NOAA Fisheries, USA In honor of Mother's Day, the Citizens of the Sea blog salutes ocean-going...

Did Whale Evolution Go Backwards?

Whales swim, but their ancestors walked. Whales are mammals (like us) whose ancestors lived on land. Life probably began in the ocean and then evolved to colonize the land. Yet the whale’s ancestors gradually...

Top Predators Timeline

What makes a top predator? Razor-sharp teeth? Speed? Strength? Size? Who is the most fearsome hunter? It depends on where and when you look.

Pages