Why human brains were bigger 3,000 years ago

The evolution of the human brain

The human brain, in all its staggering complexity, is the product of millions of years of evolution. Read on to find out about brain size and intelligence, language and brain development, and more.

The role of fire in the evolution of humanity's big brains

Roughly 1.5 million years ago, the brain size of our hominin ancestors exploded. To understand why, Richard Wrangham posited the cooking hypothesis, arguing the adoption of fire as a means to cook food had a lasting impact on our ability to digest...

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.

Why humans survived and smarter species did not

This interview with Joseph Henrich, a renowned professor of human evolutionary biology, unpacks human history. Henrich shares interesting information about why humans succeeded as a species (the answer isn't IQ), how cultural evolution works, why the human brain is shrinking, and how the Catholic Church played a role in the Industrial Revolution. Listen and watch for a deep dive into human evolution.

Human origins 101

Learn about the over 20 early human species that belong in our family tree and how the natural selection of certain physical and behavioral traits defined what it means to be human.

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...

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.

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 our ancestors didn't have crooked teeth

The ancient human fossil record is filled with specimens with pretty nice teeth. So why do modern humans have dental problems? Scientists can't be certain, but one hypothesis suggests the evolutionary shrinking of the human jaw crowded our mouths,...

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.

Why do humans have such long childhoods?

Humans have over twice as long childhoods than other animals with similar lifespans like whales and elephants. A human child can grow for nearly 20 years before they become a reproducing adult. Researchers believe there's a connection between long childhoods and human's unusually large brain size, though the science is not totally clear. Dive into what scientists know here.

How humans evolved from single-cell organisms

Humans have had a long history. 3.8 billion years in the making, to be precise. From the primordial puddle to the modern day, here's how humans have evolved from the first life.

The archaeological discovery that shifted scientists' understanding of human evolution

In 2003, archaeologists in Indonesia uncovered the remains of a 3-foot-tall skeleton that appeared to belong to a new type of human. Read this article to learn how the discovery of this 50,000-year-old skeleton upended the idea that human evolution...

Human ancestors: a guide

Modern humans are not the only creatures classified as part of the Homo genus. This article examines the eight other humans that fall under the Homo umbrella.

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

Researchers have found that low genetic diversity among humans—even those on opposite sides of the planet—may result from a breeding population of as few as 1,280 adults, estimated to have existed 930,000 years ago. This genetic bottleneck may have resulted from a near-extinction or from a small population of human ancestors, from which we all descend, that broke off from a larger population.

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.

Three examples of how humans are still evolving

For much of nature, natural selection and "survival of the fittest" still play a dominant role; only the strongest can survive in the wild. As little as a few hundred years ago, the same was true for humans, but what about now?

Even in recent history, adaptations to the environment drove human evolution

Through genetics, environmental pressures, and cultural influences, humans have evolved to tolerate lactose, develop varying skin pigmentation, and acquire genetic resistance to diseases like bubonic plague. The metabolic and digestive systems of Indigenous peoples have adapted to their diet, which is influenced by the availability of food and water.

Here's how early humans lived

Explore the evidence of early human behavior—from ancient footprints to stone tools and the earliest symbols and art – along with similarities and differences in the behavior of other primate species.

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.

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.

Watch the history of human migration that led to civilizations

Starting in Africa where they hunted with spears and fires, humans would gradually move out of the continent over thousands of years as they navigated crossing deserts, rivers, uneven terrain, and shifting climates. Development of technology, language, farming, and other societal structures helped build up the first civilizations.

Homo sapiens may have migrated into Europe earlier than previously believed

Archaeologists used to believe that Homo sapiens migrated to Europe from Africa about 42,000 years ago, at about the time that Neanderthals went extinct. This 27-minute podcast episode explores new evidence that suggests Homo sapiens migrated about...

How do we know what prehistoric humans ate?

Without recourse to ancient menus, how can historians know what our ancient human ancestors—as far as 3 million years ago—ate on a daily basis? Researchers evaluate several factors, including the type of teeth the species had evolved, chemical analysis of the teeth, patterns of wear and tear on teeth, as well as food scraps found in the vicinity of ancient remains. Learn the approach to discovering ancient hominin diets.

The lifestyles of early humans

For 2.5 million years, humans lived on Earth without leaving a written record of their lives—but they left behind other kinds of remains and artifacts.

Were humans the only hominin to walk upright?

When you imagine the line human evolution has taken, you might picture the March of Progress, an image of several chimp-like ancestors marching toward the implied final form: the upright bipedal Homo sapiens. Turns out this image, popularized in the...

A historical tree of technological advancement

Starting from stone tools millions of years ago and culminating in today's cutting-edge tech, this thorough genealogy lays out how humanity has progressed in its use of tools over thousands of years. See descriptions, links to further info, and how each tech fits in the larger tree.

What ancient goat teeth reveal about ancient human-animal relationships

About 4,000 years ago, several goats with terrible teeth managed to outlive their better-teethed brethren. With such intense dental damage, the goats were likely fed higher-quality feed than the more dentally gifted herd members, a dietary shift that would've contributed to the difference in life span. These goat teeth underscore the hard truth that humans may inflict harm on the animals they care about most, regardless of intention.

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.

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.

The history of skull modification

The ancient Maya people sometimes modified their skulls to appear more conical. Body modification has been a human pastime for literal ages, from piercings to bindings and everything in between. Modifying one's skull shape may have been a way to symbolize status, beauty, belonging, or belief. The health impacts of such practices are still debated. This article explores the history and health impacts of skull modification, also known as artificial cranial deformation.

Why portraits of Neanderthals vary so drastically

Neanderthals, humanity's long-lost genealogical cousins, are often portrayed as bumbling, hairy, cave-dwelling misogynists. But other efforts show tall, dignified creatures not too different from contemporary people. This article explores why most visual interpretations of Neanderthals are more in the service of social or political beliefs instead of science.

When humans discovered fire

Fire has proven crucial for the development of human civilization, but there was a time when our hominin ancestors could not make effective use of it. This article traces the major milestones in humanity's journey with fire based on evidence from...

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

Here's how humans migrated across the world

From our deepest origins in Africa all the way to the Americas, by looking at the fossils and archaeological materials we have been able to trace the path our ancestors took during thee short window of time when we took over the world.

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.

Neanderthals 101

Who were the neanderthals? Do humans really share some of their DNA? Learn facts about Neanderthal man, the traits and tools of Homo neanderthalensis, and how the species fits into our evolution story.

Like fingerprints, brain anatomy is unique too

Researchers have discovered that a combination of experiences and genetic factors shape the anatomy of the human brain. They found even quick experiences affect the brain’s genetic makeup, which—over time—means every person develops a completely unique brain anatomy. While brain imaging could be used to identify individuals, it remains much more expensive than fingerprinting for now. Read to found out more about this study from the University of Zurich.

Humans may be the ultimate invasive species

Originating in East Africa, Homo sapiens migrated across the world beginning about 60,000 years ago and directly harmed countless species by consuming resources and modifying ecosystems to serve our needs. While meeting the definition of an invasive species, some ecologists argue the opposite, claiming that humans have helped preserve numerous species.

Ancient humans settled Australia more than 50,000 years ago

Archaeological evidence shows that modern humans reached Southeast Asia about 70,000 years ago and they spread to Australia by at least 50,000 years ago. It marks the oldest evidence of open-sea migration by humans on record.

Human anatomy provides evidence for evolution

Throughout history, scientists have used anatomy to support the Theory of Evolution in three main ways. Homologous structures, or similar physical features in organisms that serve different functions, can help scientists understand common ancestors....

The Ishango bone suggests mathematics was born about 20,000 years ago

Ancient civilizations developed mathematical systems for various purposes, including the Egyptians for the construction of the pyramids and the Ancient Greeks for logical reasoning in theorems. However, these systems were predated by the Ishango bone—found in the Democratic Republic of the Congo—whose notches suggest a base ten system, prime numbers, and simple mathematical operations.

Without dinosaurs, plants could produce fleshy fruits with bigger seeds

Previously disturbed by massive herbivores, denser and darker forests shifted plant evolution, reaching the greatest diversity of seed sizes, fruit sizes, and fruit types about 50 million years ago.

Uncovering the evolution of history's largest dinosaurs

This article details how sauropods—the dinosaurs that Little Foot would call longnecks—repeatedly evolved to attain such colossal sizes, towering over other land critters, including tyrannosaurs and mammoths. Sauropods were giant, long-necked...

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.

A timeline of human fossil discoveries

A key part of writing a coherent story about our origins is finding and identifying the remains of our ancestors and understanding their significance. Scientists will not always agree on identifications and opinions will change as new find are made and new ways of studying them are developed.

The earliest evidence of cancer was found in a 1.7-million-year-old fossil—discovered in the toe of an ancestor of modern-day humans.

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.

Can you guess which ancient human skull is which?

When scientists discover a new fossil skull, they compare it to skulls that have already been identified as particular early human species. In this activity, you get the chance to be the scientist! Choose a mystery skull to identify by clicking on it.

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.