The first criminal conviction through the use of DNA evidence was in 1988

The Golden State killer case spotlights how genetic testing can affect your—and your relatives'—privacy

Police managed to use consumer DNA test results to close a case 32 years after a killer was believed to have committed at least 12 murders and 50 rapes. Their "smoking gun": They compared a DNA sample from the crime scene to genetic data relatives had shared on an open-source genealogy database. The suspect was caught after investigators explored family trees on this database and connected the dots from over 100 distant relatives who had some percentage of DNA that matched the killer. (Some users may encounter a paywall.)

Ancestry testing matches DNA to known genetic variants found in specific ancestries

After a lab receives a person's sample, the DNA is separated into single strands, which are chemically cut into smaller fragments. The fragments are then fed into an array of variants of known origins, and technicians observe if a person's fragments bind to specific variants.

Half of human DNA is inherited from each parent

Within most cells reside 23 pairs of chromosomes made of tightly wound DNA, and half of each pair is inherited from each parent. The 23rd pair consists of two X-shaped chromosomes, or one such chromosome paired with a Y chromosome, and determines biological sex.

Modern genetic testing stems from a 1950s discovery about the cause of Down syndrome

Scientists found that an additional copy of chromosome 21 causes the disease and developed an approach to stain chromosomes so they could be manually sorted and counted, which is called karyotyping. The breakthrough discovery by Marthe Gautier, a young French doctor and cytogenetics researcher, was appropriated by a male colleague, who listed himself as the lead author of the study reporting the finding.

See the history of DNA sequencing

DNA sequencing evolved from manual methods to automated, high-throughput technologies. The Human Genome Project was possible in the first generation of gene sequencing technology with the "chain termination method," which won developer Fredrick Sanger a Nobel Prize.

Glowing chemicals allow scientists to read DNA like a barcode

The process of determining the order of nitrogenous bases in DNA involves first cutting the DNA into fragments, which are duplicated multiple times using bacteria. Fluorescently labeled terminator bases are added to fragments, which are sorted by length and read via laser to reconstruct the sequence.

The history of the gene: an interactive timeline

Humans didn’t need modern technology to figure out that kids tend to look like their parents. But what did humans believe about genetics before we knew about DNA or cells in general? Explore this interactive timeline to see how philosophers and scientists throughout the ages tried to explain how traits are passed from generation to generation.

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...

Here’s how different genetic disorders get passed on

The human genome is complex, as identified by the Human Genome Project. This article digs in to genetic disorders, the most common ones, and how they are diagnosed.

DNA computing allows for storage and processing of massive amounts of data

Although costly and less efficient for simpler tasks, as of 2025, DNA could hold 455 exabytes of data with near limitless parallel computation potential in small data centers. Every movie ever made would fit inside the volume of a single sugar cube.

Watch DNA replicate itself before cell division

In the average adult human, between 50 billion and 70 billion cells die daily, requiring them to replicate their genetic instructions before dividing into new cells. This process relies on various proteins to unwind, read, build, and proofread new strands, with error rates of fewer than one per 1 billion nucleotides.

Watson and Crick revealed DNA's double-helix structure using others' key findings

Their 1953 model, made from cardboard cutouts, explained how DNA stores genetic information through base pairing. Rather than experimenting and collecting their own data, they incorporated patterns and data from other scientists through trial and error.

Extremely rarely, there can be twins with different dads—but fewer than 20 such cases are documented worldwide

The non-identical twins, who would also be half-siblings, result from a rare biological phenomenon called heteropaternal superfecundation. Britain's first known twins with different dads, featured in this article, learned of each other's existence in recent years, when they were both 45. They discovered each other after taking DNA tests from Ancestry, a genealogy company.

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.

Despite privacy risks, scientists are using DNA in the air to assess ecosystem health

While DNA in soil and water samples has long been used for such analyses, airborne DNA is being incorporated into such efforts to monitor individual species abundance, detect invasive species, measure biodiversity, and determine the success of conservation actions. Future work may include detecting attacks from biological weapons.

Mitochondrial DNA swapping can occur before or after fertilization

Mitochondrial replacement therapy can be conducted with four different techniques, with varying genetic material transferred depending on the approach. Maternal spindle transfer, one common method, involves transplanting the nuclear DNA from a mother into an unfertilized egg from a donor. The donor egg is then fertilized and implanted into the mother's uterus using in vitro fertilization. Another major approach, pronuclear transfer, does the genetic swapping after the mother's egg has already been fertilized. This order of operations may be uncomfortable for some individuals, but the success rate with this technique is higher.

The 4% DNA difference between humans and chimps

On the genetic level, we’re not all that different from chimps. But those small differences in DNA can have huge effects. This 11-minute video digs in to the topic.

See a timeline of the Human Genome Project

Despite starting on October 1, 1990, the goal of mapping all the DNA found in a human being was first planned in 1984. The project would reach its goals two years ahead of schedule in 2003.

All publicly available DNA sequences are available at GenBank

The National Institutes of Health's database stores comprehensive, annotated DNA sequences as part of the International Nucleotide Sequence Database Collaboration. It encourages unrestricted data access within the scientific community while allowing submitters to retain intellectual property rights over their data.

Where do genes come from?

There are many more genes on Earth today than when microbial life first spawned on the planet about four billion years ago. Many of these newer genes grew from genetic mutations, misprints that slowly drift from the original blueprint via cellular division. If these mutations drift far enough, they can establish a new family of genes, though this process can take well over a million years.

CRISPR-Cas systems act as genetic memory banks for defending bacterial cells

When viruses called phages inject DNA into bacteria, some bacterial species store bits of this DNA in their own genomes. This allows them to recognize and destroy the same virus if it attacks again.

The first successful IVF pregnancy was in the United Kingdom in 1978

Gynecologist Patrick Steptoe and his collaborator Robert Edwards, a biologist, attempted to fertilize a human egg cell in a petri dish 101 times before finally succeeding. This resulted in the birth of Louise Brown—at the time referred to as a "test tube" baby—in 1978, who was born into the spotlight.

Everything scientists could learn by looking at your skull

Our skulls are all unique, but they also share characteristics across groups of people. In the absence of fingerprints, forensic scientists can learn a lot about you just from your skull.

A Mississippi man was tried six times for the same crime, each time before an all-white or nearly all-white jury

This podcast investigates how prosecutor Doug Evans systematically struck Black jurors across decades of cases. The team built a database of every jury strike Evans made over 20 years, uncovering a racial pattern that was later cited by the Supreme Court when it overturned Curtis Flowers' conviction in 2019.

Doctors use three key physical markers to determine biological aging

The length of the ends of chromosomes (known as "telomeres"), the gradual change in collections of DNA molecules called "methyl groups", and the secretion of inflammatory proteins are all used as indicators of biological age.

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.

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

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

The story of Dollree Mapp, whose legal challenge over her 1957 conviction for possessing "obscene material" led to a major strengthening of the Fourth Amendment

See 33 images that became central to huge scandals, including a young Charles and Camilla, Michael Jackson's baby on a hotel balcony, and Hugh Grant's mugshot.

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

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

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

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

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.

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.

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.

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

The 2026 Ebola outbreak is hampered by a lack of vaccine against the species of the virus, heightening the need for rapid tests to aid in disease control.

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

Salvador Dalí believed he was his own dead brother, who had died nine months before he was born

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.

Dozens of S&P 500 stocks, including Coca-Cola and Walmart—known as the dividend aristocrats—have increased dividends every year for 25 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.

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 first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

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.