Why our ancestors didn't have crooked teeth

What ancient goat teeth reveal about ancient human-animal relationships

About 4,000 years ago, several goats with terrible teeth managed to outlive their better-teethed brethren. With such intense dental damage, the goats were likely fed higher-quality feed than the more dentally gifted herd members, a dietary shift that would've contributed to the difference in life span. These goat teeth underscore the hard truth that humans may inflict harm on the animals they care about most, regardless of intention.

How do we know what prehistoric humans ate?

Without recourse to ancient menus, how can historians know what our ancient human ancestors—as far as 3 million years ago—ate on a daily basis? Researchers evaluate several factors, including the type of teeth the species had evolved, chemical analysis of the teeth, patterns of wear and tear on teeth, as well as food scraps found in the vicinity of ancient remains. Learn the approach to discovering ancient hominin diets.

The messy story of humanity's genealogical past

For decades, scientists viewed the human fossil record and concluded Neanderthals, an early hominin, came before homo sapiens, or modern humans. The story became more complicated as technology advanced and ancient DNA samples were analyzed. This video breaks down the evidence, concluding the development of humanity was a lot messier than previously believed.

The Paranthropus genus, our mysterious extinct cousins

In the last century, skull and jaw fragments have been discovered in East Africa suggesting an ancient hominin species lived, evolved, and died alongside humanity's ancestors. With large, broad skulls and strong jaws, the Paranthropus genus—which includes several related species—is an absorbing case of the effects of niche partitioning, where species coexist by adapting differently to the environment. Paranthropus died out and human ancestors endured. Find out why here.

Vikings had pretty bad teeth

Vikings, the medieval marauders of northern European land and seas, were actually famous for their excellent hygiene. Despite this, evidence from Viking burial grounds points to one exception: their teeth. Roughly 60% of those Vikings studied had at...

Why human brains were bigger 3,000 years ago

Our modern civilisation may be the most advanced to ever exist on Earth, but around 100 generations ago, our ancestors had brains that were larger than our own.

Evidence of cancer has been found in a 1.7-million-year-old fossil

Cancer has existed as long as humans have, with some of the earliest evidence found among fossilized bone tumors, human mummies in ancient Egypt, and ancient manuscripts. The oldest example was uncovered in a toe—millions of years old—from an ancestor of modern-day humans.

Ritual Maya dental ornaments may have prevented tooth decay

Analysis of Maya dental sealants shows they used plant resins and gums—some derived from pine with antibacterial properties—suggesting gemstone tooth inlays may have helped reduce infection while serving ritual and symbolic purposes.

How dentistry evolved from carnival sideshow to respected medicine

The field, which has remained siloed from other medical care, also has a separate insurance system. This podcast walks through how and why dental insurance often remains capped at $1,500 primarily to cover cleanings, and it wouldn't cover catastrophes—unlike many other medical or housing insurance models.

Variations in beak shape helped birds survive the dinosaur extinction event

The asteroid that struck Earth 66 million years ago killed some avian dinosaurs. The smaller species endured by reproducing more quickly and adapting to the environment. Their different beaks allowed them to eat more varied foods for survival.

Humans won't develop more than 5 fingers because it would impact too many body parts

All modern animals have five or fewer digits on each of their limbs. Roughly 348 million years ago, at least two species had eight: the Ichthyostega and the Acanthostega. According to Dollo's law, complex evolved features are very unlikely to recur in evolution. Researchers believe humans won't develop more than five digits because it would impact other body parts too much.

The history of skull modification

The ancient Maya people sometimes modified their skulls to appear more conical. Body modification has been a human pastime for literal ages, from piercings to bindings and everything in between. Modifying one's skull shape may have been a way to symbolize status, beauty, belonging, or belief. The health impacts of such practices are still debated. This article explores the history and health impacts of skull modification, also known as artificial cranial deformation.

The purpose of narwhal tusks has mystified researchers for centuries

Nicknamed the "unicorn of the sea," narwhals have no teeth aside from two canines that grow directly forward as tusks. For roughly 85% of females, they stay embedded in the bone. For males, they grow into large, spirally tusks that are full of nerve endings and blood vessels. Scientists today believe that tusks likely formed for sexual selection purposes and eventually evolved to assist in other processes, such as hunting.

When did humans start kissing romantically?

This article explores the ancient roots of romantic kissing. Current archaeological evidence dates sexual and romantic lip kissing to about 2,500 BCE. A Mesopotamian clay tablet from the time shares a tale of two deities locking lips. There's also...

Why surgeons implant teeth into eyes

What if the thing that restored your vision… was your own tooth? That’s exactly what happened to Brent Chapman. After 20 years without sight, a bizarre surgery using his tooth as a lens restored his vision.

Some animals have little or no bacterial populations in their gut

Gut microbiomes are essential to human health, but many animals have a much smaller, transient, or even nonexistent microbiome. The discoveries have advanced our understanding of the evolution of the human microbiome.

Unlike the roars in movies, dinosaurs likely cooed, rumbled, and boomed

Fossil evidence and CT scans suggest that many dinosaurs produced low-frequency sounds using resonating crests, closed-mouth vocalizations, or organs similar to those of birds and crocodiles. Larger sounds would not have been helpful for sneakily hunting prey.

Why some people have allergies

Why do some people have allergies while others don’t? One theory suggests allergies are a relic of our evolutionary past. Our immune system, once primed to fight parasites, now mistakes harmless substances for threats.

The ancient engineers inspiring modern building practices

Modern concrete structures need replacing every 50 to 100 years, so why are buildings by the Maya, ancient Rome, and ancient China still standing strong? This article details how scientists are looking into humanity's past for clues on how to craft long-lasting structures. Part of the problem is adopting old material recipes to hold up to modern demands.

Flossing may lower the risk of strokes

Flossing is known to advance teeth and gum health, but it also betters one’s brain and heart health. According to data from the American Heart Association, taking care of your teeth has cardiovascular benefits. A recent study showed that regular flossers experienced lower risks of strokes, highlighting a link between oral bacteria and stroke risk.

Cats have a mutation preventing them from tasting sugar

When certain tastes (sweet, umami, bitter) become irrelevant due to a species' diet or lifestyle, the genes for those tastes degrade. In felines, scientists believe a shift to a protein-heavy diet put evolutionary pressure on the genes responsible for tasting sweetness. (Some users may encounter a paywall.)

The gene that changes sharks to skates

Sharks and skates (similar to stingrays, without the stinger) look different enough that it's reasonable to assume they aren't related. However, a new study suggests that a microscopic change at the cellular level caused skates to branch off from sharks as they evolved. Scientists believe roughly 285 million years ago, the 3D structure of shark DNA shifted, disrupting the relationships between key genes, and resulting in the flat, symmetrical shape of modern skates.

The anatomy of coral polyps, whose mouths consume food and expel waste

The mouth is surrounded by tentacles that help clear away debris and defend the organism, using stinging cells called nematocysts that resemble those of jellyfish. Connective tissue called coenosarc connects individual polyps within colonies and allows them to share nutrients.

How flowering plants took over the world

Flowering plants are relatively young in the evolutionary scheme of things, only arriving after the dinosaurs had already been wiped out. Their evolution has long puzzled scientists, but recent research indicates their success is due to smaller,...

The science of symmetry | The Royal Society

Nature is full of symmetries, from spiral galaxies to florets of broccoli. So why do complex creatures break the pattern?This short video discusses why symmetry came to dominate life on Earth, and how many complex life forms, such as humans, transitioned from radial to lateral symmetry.

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

The Brothers Grimm were lawyers before they were storytellers, and became interested in fairy tales as they began investigating how rules and customs had been passed down through cultures.

The animatronic shark from Steven Spielberg's 'Jaws,' the first modern blockbuster, was a complex underwater apparatus called 'Bruce.'

Despite being favored by 87% of Americans, Congress does not have term limits.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'