Why genetic similarities between humans suggest a past near-extinction event

Studies estimating the number of years between human generations suggest there have been approximately 10,000 to 12,000 generations of humans.

Research has found that the length of human generations has varied throughout the 300,000 years that Homo sapiens have been around, ranging from about 25 to 30 years. These values come from analyzing genetic mutations, since the blend of them passed onto children changes as parents age.

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.

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.

Ancient humans and other early hominins were closer than you might think

Evidence that human ancestors and other early hominins coexisted continues to accumulate, raising the question of just how close these ancient people truly were. This article details how evidence is changing the theory that early hominins like...

Genetic analysis suggests Anopheles mosquitoes fed on humans some 1.8 million years ago

The 2026 paper, based on 11 species of Anopheles mosquitoes found in Southeast Asia, suggests that mosquitoes in the region likely developed their human blood preference between 2.9 million and 1.6 million years ago, overlapping with when scientists believe Homo erectus arrived there. (Some users may encounter a paywall.)

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?

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.

The evolution of the human diet

Could eating like our ancestors make us healthier? One estimate suggests prehistoric hunter-gatherer communities obtained 75% of their calories from meat and fish.

The lack of diversity in DNA databases limits their applications

European ancestry dominates genetic research, hindering the usage of genetic databases for precision medicine for other groups, including African Americans, who face higher health risks due to genetic variants. Many Indigenous communities have also resisted genetic research due to past exploitation. (Some readers may experience a paywall.)

Genetic analysis indicates that every organism on Earth evolved from a single cell

LUCA—the last universal common ancestor—lived about 4.2 billion years ago and likely obtained energy through the conversion of carbon dioxide and hydrogen gas consumed from atmospheric gases at the ocean's surface or hydrothermal vents—openings on the seafloor where fluid warmed and enriched with minerals by Earth's interior is expelled.

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

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

Interactive human migration map

Using archeological, genetic, and climate data, scientists have pieced together an outline of the human odyssey—the journey that took our species from Africa to all corners of the globe. Experience this 200,000-year migration using an interactive human migration map.

Why humans evolved single-child pregnancies

While birthing twins has been a rare occurrence for humans, research suggests that twins were actually the norm much further back in primate evolution. It’s proposed that single-childbearing turned out to be critical for the evolution of larger babies with larger heads. Discover more about the shift that gives insight into primate evolution.

The oldest DNA recovered so far is 2 million years old

The oldest DNA recovered so far is about 2 million years old and has given scientists an unadulterated peek into ancient history. This nine-minute video explores the findings and implications of the DNA, which was pulled from frozen soil in...

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.

See a timeline of landmark discoveries in the field of genetics

From the first genetic map of fruit fly genes in 1911 through the completion of the Human Genome Project in 2003, scientists have built upon each other's discoveries to further our knowledge of the human body and the genetic instructions that inform our traits and disease risks.

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.

Measles evolved from an ancient cattle disease as early as 3,000 years ago

Genetic analysis suggests that the closest modern relative of measles is a livestock virus known as rinderpest, with the viral strains diverging between 2,000 and 3,000 years ago. The timing coincided with the rise of major cities above 250,000 people, offering a novel transmission route for the newly mutated measles virus.

European diseases killed a massive share of the Native American population

After Western contact, epidemic diseases devastated Indigenous communities. By 1920, the Native American population of the US had fallen to roughly 270,000, compared with an estimated 1.2 to 18 million at the time of European arrival.

Early farming created population booms—and also major busts

Europe’s ancient embrace of farming took the continent on a demographic roller-coaster ride. Regional booms and busts in human numbers occurred between 8,000 and 4,000 years ago, a new study finds.

Tracing the history of the philosophy of human extinction

Global catastrophe is at the center of much contemporary debate over climate, war, science, technology, and more, and our period is marked by a lurking sense everything we know—including the human species—could end overnight. It wasn't always...

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.

De-extinction techniques create new species from existing organisms

Rather than recovering a genetic sample of a lost species and editing it with that of living creature—as has been depicted in science fiction—scientists begin with living cells from close genetic relatives and use tools like CRISPR to swap in extinct versions of specific traits to create new hybrid species.

Native, wild bees are at much greater risk of extinction than honey bees

It is estimated that there are more honey bees, which often compete with native bees for resources, on the planet than at any point in human history. Meanwhile, 40% of invertebrate pollinator species, including wild bees and butterflies, face extinction in the coming decades.

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.

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.

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.'

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

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

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.

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

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.

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

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

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

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.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

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.

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

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.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

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

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

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

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.

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