The 4% DNA difference between humans and chimps

All humans share 99.9% of the same DNA

Of the 3 billion base pairs that make up the human genome—the complete set of genetic material for the species—the diversity of humans is the result of variations in about 3 million molecular bases. The closest nonhuman genetic match is the chimp, with 98.8% similar genetics.

Where are humans on the evolutionary tree?

This interactive tree-shaped map explores the evolutionary connections between more than two million species. According to this map, humans are on the same branch as great apes, tarsiers, and treeshrews. That branch then splits into even smaller branches, with humans appearing on the same twig-like branch as chimpanzees and bonobos.

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.

Around 5 million of our 3 billion DNA letters differ between individuals

Genetic testing examines gene variants to help explain disease symptoms. It explores how genetic differences between individuals can be used to understand risks of developing diseases like Huntington's Disease or passing variants linked to disease onto offspring.

What percent Neanderthal are you?

Many of us carry around 2% Neanderthal DNA in our genes. Museum human evolution expert Prof. Chris Stringer discusses why and what it means.

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.

Explore different living beings' sizes, from DNA to whales and the Pando clone

The Pando is actually a single organism in Utah, comprising more than 47,000 stems connected by a vast root system. It spans roughly 108 acres. Meanwhile, the average human stands at 5 feet and 7 inches. DNA, the genetic instructions for life, stands at a height of 3.5 nanometers.

Sex determination isn’t all XX and XY

We’re generally taught that chromosomes determine an animal’s sex, but it is way more nuanced than that. Watch this 12-minute video to find out how.

Up to 8% of the human genome consists of ancient viral DNA

Human endogenous retroviruses are remnants of infections that affected human primate ancestors millions of years ago and were passed on by infiltrating sperm and egg cells. Studies have shown that this DNA may play a role in immune responses and in placental formation.

Chimpanzees are dying from human colds

For some great apes, the threat of human-borne diseases outweighs poaching or habitat loss. This article details the danger of reverse zoonoses, which refers to diseases that spread from humans to animals.

Why your dog’s DNA isn’t destiny

DNA tests tell people about their pet’s breed and attempt to predict things about its behavior and health. But for all that these tests might provide some interesting results, they need to be taken with caution. Here's a look at what we can and can't learn from our pets' DNA.

Organisms can possess multiple unique sets of DNA in one body

Genetic chimeras can result when cells with different DNA combine, such as when two sperm cells fertilize two egg cells, creating two embryos that then merge. In mosaicism, mutations arise within an organism after conception and can spread through cell division, resulting in diseases and forming genetically distinct anatomy.

Humans may have evolved to need less sleep

Humans sleep less than most primates—but more efficiently. Chimps sleep 9.5 hours with 5% in REM, while humans get seven hours with 25% in REM. Some predict we may one day need just five hours, but for now, our sleep patterns balance rest and function, shaped by evolution and environmental stability.

Watch how DNA is packaged to a 10,000th of its original size in a cell

In humans, the 2-meter (6.56-foot) molecule wraps around spool-like proteins called histones, forming beads—nucleosomes—that fold up into fibers. These fibers—chromatin—form loops through folding that compress into larger fibers, which tightly coil together to form a chromosome.

The features that make our voices unique

Human voices are about as unique as fingerprints: similar instruments but with endless variations. We each produce sound in the same physiological way, but when we talk we’re dropping clues about who we are, what we do, and where we’re from.

An interesting perspective on whether (and how) brain size matters in cognitive ability

Some brains are bigger than others, but what is the relevance, if any, to brain size and intelligence? This Scientific American article explores the question and offers examples. It also visually compares frontal slices of several mammals' brains, showing that humans don't necessarily have the biggest cerebrums on the block.

Is human evolution speeding up or slowing down?

In the past 3,000 years, many populations have evolved genetic adaptations to their local environments. People in Siberia and the high arctic are uniquely adapted to survive extreme cold. The Bajau people can dive 70 meters and stay underwater for almost 15 minutes. So what are other recent changes? And will our technological innovations impact our evolution?

Humanity's reduced body hair slows down wound healing

Cuts to human skin take twice as long to heal compared to chimps and other mammals. Scientists argue this is due to the reduced number of hair follicles on human bodies. Hair follicles contain stem cells which help repair skin cells faster, so as humanity shed its hair over time, so to speak, it also slowed its wound healing.

Twin studies helped scientists understand why mosquitoes like some of us more than others

A combination of carbon dioxide output, skin chemistry, genetic factors, hormones, and clothing choice can make us particularly vulnerable to mosquito bites. Watch how mosquitoes responded to one man in the video versus his wife, a research approach typically conducted with identical and fraternal twins to test mosquito attractiveness.

Humans have existed for just 0.004% of Earth’s history

Born from the remains of the molecular cloud that birthed the sun, Earth experienced planetary-scale collisions, asteroid impacts, and lava seas. Life became possible after the planet cooled and formed a thin crust, atmosphere, and oceans.

The complexity of classifying a tree

It may seem obvious to us when we see a tree, but very specific characteristics cause scientists to distinguish trees from other types of plants. This video provides a visual and verbal explanation of distinctions that separate trees from other plants like shrubs or herbs. See a scientific breakdown of these traits.

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.

A student researcher working on the Human Genome Project shares their perspective

In a conversation with Ewan Birney, Director of the European Bio-informatics Institute, he discusses what it was like to be a PhD student working on the Human Genome Project in the months before the draft announcement and its impact on him and the field of genetics.

Can animals understand fairness?

Academics have long wondered if fairness is solely a concern of humans. In the largest meta-analysis to date, UC Berkeley researchers tested whether monkeys felt jealousy after receiving unequal rewards. The patterns showed low evidence for inequity aversion and instead frustration due to their expectations not being met by humans. These findings suggest that pursuing fairness and equality is uniquely human.

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.

A primer on human tears

Tears are one of the many behaviors that differentiate humans from the rest of the animal kingdom. Why do we cry? This comprehensive and well-written essay explores various theories about why we cry, observes tear fluid as the only one that does not elicit disgust, and attempts to interpret the meaning of tears in different circumstances. See what all the fuss is about here.

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

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

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

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

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

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

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.'

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.

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

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Watch how algorithms can be designed to train themselves and self-improve without human input, to the point where the optimized code is too complex for programmers to understand.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

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.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

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

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

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.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

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.

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.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

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

Watch this video that uses Lego bricks to explain how venture capital works.

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.