The wild ancestors of dogs first mingled with humans 15,000 to 30,000 years ago

Studies suggest only 9% of a dog's personality comes from its breed

While all dogs descend from wolves domesticated and bred for specific tasks by humans at least 15,000 years ago, most behavioral characteristics result from a mix of genetics and environment, which result in diverse canine dispositions within the same breed.

The genetic links between different dog breeds

There are nearly 400 modern domestic dog breeds with unique histories and genetic profiles, many of which share genetic traits based on their geographic origin. This visualization captures the links between 150 common breeds—for example, boxers share genetic variants with 11 of 16 breeds of European Mastiff, along with five others outside of that group. Explore which breeds your pet is linked to with this chart.

The science of dogs, from wolf origins to color-blindness

This under 10-minute podcast episode dives into the rich, fascinating science behind dogs: From their world-class sense of smell to their domestication from wolves.

Cats began cozying up to humans around 10,000 years ago

The feline family is a hugely diverse group of lions, panthers, and kitties that have spread all over the world. The ancestors of the cats we love today helped solve rodent problems when humans first invented agriculture. They've been worshipped, loved, and scorned by humans since.

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 Dog Aging Project uses information from over 50,000 dogs to explore longevity

The study gathers health, lifestyle, and genetic data to understand what helps dogs live longer, healthier lives. Findings could also provide human health insights due to our shared surroundings and biology.

The genetic diversity of dogs is greater within Chernobyl than in surrounding areas

A 2023 study identified that packs of dogs located just 16 kilometers (10 miles) apart within the exclusion zone were more genetically different from one another than from stray dogs hundreds of kilometers away. Rather than radiation, this is likely the result of inbreeding within isolated packs.

What we know about aurochs, the ancestors of modern cattle

The relationship between humans and cattle is invaluable and longstanding. Evidence suggests cattle's wild, larger, and now-extinct ancestors, the aurochs, were also linked to early humans. Similarly valuable for their milk and labor power, yet significantly more threatening due to their size, aggression, and speed, auroch domestication was slow and complex. Discover new information about the fascinating ancestors of modern cows and the potential of re-introducing the species with selective breeding.

Cadaver dogs are helping archaeologists uncover decaying history

Archaeologists are increasingly relying on dogs to help find decaying bodies at burial sites, some of them up to thousands of years old. This is helping archaeologists to detect past remains without ever touching a shovel, which means there's less...

Humans are more genetically similar to cats than to dogs

While humans are not closely related to either cats or dogs from an evolutionary standpoint, scientists find that human and cat chromosomes are organized more similarly to each other than human and dog chromosomes, making cats a better model for studying human diseases.

For most of human history, property rights were in the elite’s hands

Humans learned to domesticate dogs long before they formed the concept of private property. But by the era of the ancient Greeks and Romans, property law and ownership became more sophisticated.

A thousand medieval dog names

In the Middle Ages, hunting was more than a sport—it was a vocation. Hounds were a crucial element of hunting, and wealthy landowners owned hundreds of them. A scribe in the late 15th century recorded more than 1,000 authentic names given to dogs, prompting a historian to speculate this showed just how well dog-handlers knew their animals. See the names here.

A history of belly buttons, from dinosaurs to modern dogs

Could dinosaurs have had belly buttons, just like you and me? Some researchers believe they've found evidence the ancient reptiles had the cute scar, a common feature among placental mammals (but which is also found in many more kinds of animals). Dive into their peculiar findings with this fascinating video.

The Adams family brought the first pets to the White House

When John Adams became the first president to live in the White House, Abigail brought along the family's dogs—making them the first presidential pets to reside there. Abigail was known for her love of dogs.

A gallery of famous artists and their dogs

Picasso often featured his photographer's dog, Lump, in paintings, due to an unusually close connection. George O'Keeffe adopted chow chows as companions and protectors in the New Mexico desert. See the pets of Lucian Freud, Frida Kahlo, and more.

'Hot dog' likely evolved from the common name 'dachshund sausages'

The ubiquitous handheld snack started in New York City, where vendors sold sausages in buns, calling out "Get your dachshund sausages!" Historians believe the change to "hot dog" was natural for many fans, who found the name funny and catchy.

The animals that paved the way for space travel

The history of animals in space exploration is often overlooked. Before humans first made their way to space in 1961, fruit flies, primates, and canines preceded us. Watch this video for a further appreciation of the contributions and sacrifices made by animals for scientific progress.

Dinosaurs emerged 245 million years ago when Earth’s continents were still conjoined

Once the supercontinent split apart, dinosaurs evolved into thousands of species as they adapted to their changing environments. All non-avian dinosaurs went extinct about 66 million years ago following an asteroid impact, while avian dinosaurs evolved into today’s birds.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Button boards may be the next step in human-canine communication

In a viral trend, dogs have been recorded using button boards to seemingly "talk" with humans. Researchers are divided on whether this means dogs have learned language or are engaging in sophisticated behavioral conditioning.

Biologists believe over 5,000 coyotes inhabit LA as of 2025

Panic and fear of coyotes spread in the 1980s after the first recorded instance of a human killed by the animal in American history, but LA and Chicago residents today are learning to live alongside the animal. Research shows that coyotes can even benefit urban ecosystems by helping to control populations of geese and deer, and by improving songbird survival through preying on cats.

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.

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.

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.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa

More than 70% of all new infectious diseases originate in animals. Referred to as zoonotic diseases, these are diseases that originate in animals and occasionally spill over or jump from animals to humans. Bats, mosquitoes, and primates have all been linked to spillover events. As human populations push further into previously uninhabited wilderness, animal-human contact increases, and disease spillover is inevitable.

When was the first blood transfusion?

In the 1600s, an English doctor transferred the blood from one dog to another via quills. The procedure ended when one of the dogs died. This article details the early days of blood transfusions, which turned toward humans shortly after the 1666 dog experiment and involved putting the blood of a sheep into a human recipient (who reportedly survived the encounter).

Tracing the evolution of mobile phones

The first cell phone was created in 1973, with a 2.4-pound handset and a battery life of about 30 minutes. Since then, pretty much everything about it has drastically changed, with more than 5 billion cellphone users across the globe (that's more than half of the world population). Learn about the evolution of the mobile phone and where the technology may go in the future with this four minute video.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

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.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

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

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

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.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

20,000 letters to the advice columnist 'Dear Abby' provide insight into prevailing sex, religion, and LGBTQ fears, anxieties, and concerns from the 1950s onward.

Hear 50 years of iconic hip-hop samples, the genre's foundational looped tracks

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

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

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

Meet the 56 signers of the Declaration of Independence—most of whom didn't put pen to paper until August 2, 1776—and see their original signatures.

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

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

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.