'Artificial embryos': The hidden steps in forming a spine

In vitro gametogenesis: using induced stem cells to fertilize eggs

Using stem cells from skin and mouth cells could save hopeful parents time and money and spare egg donors from significant amounts of discomfort throughout the process. There are potential consequences, not just for infertility treatment, but for the ability to create customized cells of any type.

The science and ethics of artificial wombs

Artificial wombs may be able to help preterm babies survive their early entry into the world and possibly curb the long-term adverse health effects associated with such premature birth. This article dives into the current ethics and science behind artificial wombs and ectogenesis, which is when a fetus develops in artificial conditions.

The human body in 3D

Zygote Body is a free human anatomy tool that allows users to explore the intricacies of the human body in stunning detail. With the click of a mouse, users can isolate by body system or view anatomical structures from any angle. Check out this...

Watch a salamander grow from fertilization to hatching

New microscopy techniques have allowed scientists to image the development of animal embryos with unprecedented detail. This six-minute time-lapse reveals the development of a salamander from initial fertilization to hatching from an egg.

How 3D printing inside cells paves the way for microscopic machines

In 2026, scientists in Slovenia developed a method to 3D print a small elephant, several microscopic geometric objects, and barcodes for cell labeling within living human cells, which continued to grow and divide thereafter. The experiment opens the door to fabricating devices within cells to study and manipulate cellular functions.

Stem cells develop into a wide range of other specialized cells in the human body

Stem cells are different from other cells because they are capable of creating copies of themselves and producing other types of cells. For example, the ones found in our brains, bones, or muscles. Curious about stem cells? Here's a breakdown of how they work.

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.

How the heart achieves its first beat

Scientists observed zebrafish embryos as they grew and isolated the several-second-long initial heartbeats to better understand this crucial moment in every heart's life. The zebrafish's heart starts beating 20 hours into their existence. Each heart cell activates electrically at random, without rhythm. As these cells mature, they become more sensitive to electrical charges; as they all fire, a rhythm is established and a pulse is born.

Scientists first observed a sperm and an egg uniting in 1876

Throughout human history, scholars and researchers have speculated on the origin of human reproduction. It wasn't until the late-19th century that the physical process of egg fertilization via sperm cells was observed (in sea urchins), forming the basis for modern fertility research.

What happens during the first eight weeks of pregnancy?

The first weeks of embryonic development, known as embryogenesis, are one of the most critical phases during pregnancy. This simple breakdown from the Khan Academy illustrates what we know about how the complex process unfolds.

Fruit fly experiments helped identify genes responsible for major body development

The insects' fast life cycle and affordability have allowed geneticists to quickly identify which genes are responsible for limbs, eyes, and other body structures by inducing mutations. The same genes may be responsible for different parts of a species' body, such as limb-building genes being responsible for wing pigmentation in butterflies.

What a tiny marine worm can tell us about our brains

Meet the amphioxus, a small eel-like animal that has a lot to teach us about brain evolution. The genetic roots of our brains can be seen in these unusual creatures. This three-minute educational video focuses on the evolutionary history of the human brain through these odd little critters with a 500-million-year-old history.

Some animals may speak because of duplicated connections in the brain

Neuroscience suggests that connections responsible for motion made during embryonic brain development—such as those connecting hearing and movement pathways that allow reactive motion when started—are duplicated and connected to the larynx in some animals. This allows some mammals and song-learning birds to speak, provided they have the necessary physiological structures.

How to repair a baby’s broken heart

A rare disorder that prevents some babies from getting enough oxygen to their organs can be repaired through a series of three intricate surgeries. This article and graphic explain the process behind correcting single-ventricle defects, also known as SVDs.This disorder happens when one of the heart's lower chambers doesn't work correctly, resulting in deoxygenated and oxygenated blood circulating the body rather than just the latter.

Exploring the link between history, art, and anatomy

Throughout centuries, art has played a vital role in sharing—and furthering—scientific understanding. This largely began in 1543 when physician Andreas Vesalius worked with an artist and engraver to transform learnings from his dissections into...

Goose bumps require a surprisingly complex series of steps

Watch an anatomical breakdown of how goose bumps work—featuring real skin from a human cadaver, a segmented brain, and a detailed anatomical model of the skin—to learn about all the jargon behind goose bump science. (Warning: Includes graphic footage of cadaver skin.)

Pig brain cellular activity was restarted hours after death in study published in 2019

Yale University scientists restored basic cellular activity and circulatory function in pig brains about four hours after death with a synthetic cocktail of preservatives and nutrients. This work— which didn't restart electricity activity in the brain or consciousness—could help advance future human stroke and brain injury treatments.

Anthropic's interpretability team discusses how AI models' thinking mimics biology

Just as humans engage in complex behaviors to survive and reproduce, teams of experts in neuroscience, virology, mathematics, and other disciplines argue that large language models develop complex mechanisms to achieve their goals. These mechanisms can be manipulated to assess how they modify outputs—much like stimulating individual neurons—to uncover how LLMs "think."

The basics of synthetic meat

Lab-grown meat companies promise to remove animal slaughter from the production process. But they have run into a few road bumps along the way.

Limb regeneration research may lead to treatments for arthritis

For scientists pursuing the cure for arthritis, the holy grail of discoveries lies in how to regrow healthy cartilage inside human joints. While this feat has so far resisted our best scientific attempts, there are plenty of other human tissues—such as the liver and fingertips—that will successfully regenerate.

People learned to fly in VR, and their brains then accepted wings as body parts

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts. The brain research has potential implications for how VR training may help people adapt to prostheses. (Free with email.)

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

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

Snakes move around by coordinating hundreds of muscles

These muscles connect to their vertebrae, and allow the creature to move in various unique ways. Snakes can slither, move in a straight line, swim, jump and even "fly."

Why do dreamers twitch?

This thought-provoking piece highlights newer research suggesting sleep twitches may not be random dream leftovers, but instead a crucial way our brains map and understand our bodies. From sleeping rat pups to dreaming octopi, this biological mapping system appears universal across animal species.

The halting of human bone growth helps manage heat produced from metabolism

While fish, amphibians and reptiles get bigger throughout their lives until they die, their slower metabolisms allow their bodies to regulate the resulting smaller temperature increases. In humans, hormones triggered during puberty harden growth plates, ending bone lengthening.

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 syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

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

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

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

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

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.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

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

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.

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

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

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

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.

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.

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

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.

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

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.

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.

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

A Yale student wrote a profound essay about the consulting industry's influence on elite college students that was published in a book of her writing after she died in a post-graduation car accident.