Charles Q. Choi

Why are dogs, especially puppies, in endless pursuit of their tails?

Mountains form in a variety of ways, some of which geologists are now just starting to understand.

Skulls housed in a German hospital's collection for a century were stolen from Africa during the colonial period. They have now been genetically matched with living relatives.

Radioactive metals and even certain gases may be capable of the kinds of reactions needed to spur life, new research suggests.

The human population may have lingered at about 1,300 for more than 100,000 years, and that population bottleneck could have fueled the divergence between modern humans, Neanderthals and Denisovans.

A newly described fossil suggests that the ancestor of humans and apes arose in Europe, not in Africa.

Fossil found in France is not quite modern human and not quite Neanderthal.

Previously, researchers thought that humans arrived in North America 13,000 years ago, but now they're finding much older evidence.

Gold is the most malleable element, but what's the science behind it?

How can you get the right mixture of sand, water and air for your sandcastle?

NASA's Perseverance rover has found an intriguing menagerie of organic molecules in a Martian crater, but their source remains unclear.

Strange, never-before-seen movements in the East Africa Rift Valley appear to be driven by super-heated rock from deep beneath Earth's surface.

Did our last common ancestor swing from trees or walk on all fours in the savanna?

Will the East African Rift split the continent and create a new ocean, or will it fizzle out?

Hair grays because pigment-producing cells get stuck within the hair follicle, research suggests.

If a cat kneads on your lap, it's likely because it feels safe around you. But why do they knead in the first place?

Scientists estimate the mass of the 1,084,954 buildings within the five boroughs of New York City is 1.68 trillion pounds.

Modern humans may descend from two or more genetically distinct streams that split but continued to occasionally mix over time in Africa.

The first wave of humans into the Americas during the last ice age may have hailed partly from northern China, according to a DNA study of ancient and modern Indigenous people.

Modern humans migrated into Europe in three waves: 54,000, 45,000 and 42,000 years ago, a new study claims.

The eruption was the most powerful natural explosion in over a century, triggering a tsunami hundreds of feet high.

The moon is slowly creeping away from Earth, but will we actually lose the moon before the sun turns into a red giant and destroys us both?

Here's why hurricanes, also known as tropical cyclones and typhoons, don't form at the equator and why it would be rare for them to cross it.

Dogs commonly tilt their heads, but is it a sign of intelligence, or does it mean something else entirely?