Evolution

For a tiny, soft-bodied worm, seeking shelter by way of hermiting behavior likely protected it from predators.

Penis Worms May Have Been the First Real Hermits

Hermit crabs may have evolved hermiting behavior 180 million years ago, but penis worms beat them by more than 300 million years

Poaching was amplified during Mozambique’s civil war between 1977 to 1992 to finance the war efforts. Elephant population numbers dropped from 2,500 individuals to around 200 in the early 2000s.
 

Female Elephants Are Evolving Without Tusks in Mozambique

The genetic mutation causing tusklessness in females seems to be lethal in males

Using micro-CT scans, the team visualized the crab's body in 3-D and even imaged its mouthparts lined with fine hairs. It is unknown if the five-millimeter-long crab is a full-grown adult, a juvenile or a baby.

This Tiny Crustacean Trapped in Amber Tells a Different Story About Crab Evolution

The Cretaceous-era fossil suggests that crabs left the sea some 50 million years earlier than scientists previously thought

After comparing all genomes, the researchers found that the Japanese wolf is part of an evolutionary branch of wolves that arose 20,000 to 40,000 years ago. Some of the wolves from this branch evolved into the Japanese wolves while others branched off and gave rise to modern dogs.

Ancient Japanese Wolves May Be the Closest Wild Relative of Modern Dogs

The results challenge previous theories about the origin of dog domestication

The 'Ubeidiya site today is an expanse of grasses. Concealed from this view are slabs of fossilized pebbly clay, a source of ancient finds that have helped scholars learn about the journeys of Homo erectus.

What Drove Homo Erectus Out of Africa?

Excavations at a site in northern Israel are at the heart of a debate about the species' migrations

A gharial has the same skull shape as some extinct crocodiles. This skull shape has likely evolved three different times during the history of crocodiles.

Modern Crocodiles Are Evolving at a Rapid Rate

Despite their reputation as "living fossils," crocodiles have changed dramatically in the last two million years

A mutation in a gene called TBXT be behind the sudden loss of great ape's tails, according to researchers.

Why Humans Don't Have Tails

Scientists pinpointed a gene that could explain why monkeys have the extra appendage, while people don’t

A thermal image shows a parrot releasing heat through its beak and talons. Researchers have found that since 1871 some parrots have increased their beak area up to 10 percent.

Animals Are Changing Shape to Cope With Rising Temperatures

Birds, bats, rabbits, mice and other creatures are growing bigger body parts to cool themselves off

Tardigrades use their claws like grappling hooks and pull their bodies forward to move.

Scientists Discover Tiny Tardigrades Trot Around Like Insects

The microscopic organism's gait may have evolved to adapt to unpredictable terrains

Though considered a whale, Phiomicetus anubis had legs with webbed feet to pursue prey on both land and sea with its powerful jaws and sharp teeth 43 million years ago.

New Research

'God of Death' Whale Was Scourge of Land and Sea 43 Million Years Ago

The prehistoric mammal possessed a powerful jaw and likely had a raptor-like feeding style

Around 20 percent of female white-necked jacobins have evolved to share the vibrant plumage characteristic of males.

Female Hummingbirds Masquerade as Males to Avoid Harassment

One-fifth of female white-necked jacobins sport flashy male-like plumage, which may help them access more food

Cane toad tadpoles are observed eating other tadpoles in South America, their native habitat. However, the cannibalistic behavior occurs more often in Australia.

Without Predators, Cannibalistic Cane Toads Eat Their Young—and It's Rapidly Accelerating the Species' Evolution

Hatchlings in Australia have halved their vulnerable growth stage to avoid becoming their pal's next meal

A spotted skunk does a handstand.

Scientists Identify Seven Species of Spotted Skunks, and They All Do Handstands Before They Spray

Researchers analyzed hundreds of spotted skunk specimens to classify the animals

Both beer and wine are thought to predate distilled spirits.

Ask Smithsonian

'Which Came First: Beer or Wine?' and More Questions From Our Readers

You've got questions. We've got experts

Before engaging in social behaviors like grooming, bonobos (pictured) employed a "hello" greeting during 90 percent of observed interactions and bid their peers farewell 92 percent  of the time.

Bonobos and Chimps Appear to Have 'Hello' and 'Goodbye' Greetings

Like humans, these apes share salutations to start and end interactions

Olympic runners compete during the 10,000 meters race in Tokyo. In ancient times, running was likely used to push animals to exhaustion during hunting.

Five Ways Humans Evolved to Be Athletes

An archaeologist explores how our prowess in sport has deep roots in evolution

This is the 93-year-old Xerces blue butterfly specimen that researchers collected tissue samples from for this study.

New Research

This Butterfly Is the First U.S. Insect to Be Wiped Out by Humans

Genetic tests using museum specimens suggest that the Xerces blue was a distinct species and that it disappeared in 1941

After analyzing the mitochondrial genome, the team discovered that the island-dwelling elephant is the descendant of straight-tusked elephants and was possibly isolated on Sicily between 50,000 and 175,500 years ago.

Ancient Elephants the Size of Shetland Ponies Once Roamed Sicily

The animals' size reduction is comparable to if humans were to shrink down to the size of a rhesus monkey

An illustration depicting some of the dinosaurs that roamed the Earth during the Late Cretaceous.

New Research

Dinosaurs May Have Been Declining Before the Asteroid Struck Earth

The researchers say the cataclysmic impact may have simply been the final nail in the dinos’ coffin

A Chinese mountain cat photographed in a field of grass.

New Research

Elusive Chinese Mountain Cats Aren't Domestic Cats' Ancestors

Past genetic studies on feline domestication hadn't included this wildcat native to the Tibetan Plateau

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