At least eight distinct species belong to the genus Homo, and our species, Homo sapiens, is the only one still alive. The others lived across Africa, Europe, and Asia over a span of nearly two million years, and several of them overlapped in time with us. Some left traces in our DNA that persist today.
The Major Human Species
The Smithsonian Institution’s Human Origins Program recognizes seven other species in the genus Homo alongside Homo sapiens: Homo erectus, Homo habilis, Homo rudolfensis, Homo heidelbergensis, Homo neanderthalensis, Homo naledi, and Homo floresiensis. The exact count is debated because fossil evidence is incomplete and researchers sometimes disagree on where to draw the line between species, but these are the most widely accepted.
Some of these species were direct ancestors of ours. Others were more like evolutionary cousins, branching off and following their own path for hundreds of thousands of years before dying out. A few were alive at the same time as early Homo sapiens, meaning our ancestors shared the planet with other kinds of humans.
Homo Erectus: The Long Survivor
Homo erectus lived between about 1.89 million and 110,000 years ago, making it the longest-lasting human species by a wide margin. It was likely the first human species to expand beyond Africa, spreading into western Asia (including the area of modern-day Georgia), China, and Indonesia. Some evidence suggests populations in Indonesia may have survived until around 40,000 years ago, which would mean they overlapped with Homo sapiens.
Homo erectus was also the first human species to look broadly similar to us in body proportions, walking fully upright with long legs. They used stone tools and controlled fire, and their success across two continents over nearly two million years makes them one of the most consequential species in our lineage.
Neanderthals: Our Closest Relatives
Neanderthals lived across Europe and parts of southwestern to central Asia from about 400,000 to 40,000 years ago. They were shorter and stockier than modern humans, with males averaging about 5 feet 5 inches and females about 5 feet 1 inch. Their bodies were built for cold climates: compact and muscular, with large noses adapted to warm and humidify frigid air. Their skulls had a distinctive oval shape with heavy brow ridges, a low forehead, and thick, strong bones.
Their brains were as large as ours and often larger, proportional to their heavier builds. They made complex tools, used fire, and buried their dead. DNA comparisons suggest Neanderthals and Homo sapiens diverged from a common ancestor, most likely Homo heidelbergensis, sometime between 350,000 and 400,000 years ago. The European branch became Neanderthals; the African branch became us.
The last Neanderthals disappeared around 40,000 years ago. Their final holdouts appear to have been small pockets of western Europe and the Near East. But before they vanished, they interbred with Homo sapiens. People of European or Asian descent carry about 1 to 2 percent Neanderthal DNA today. People of primarily African descent carry zero or close to zero.
Denisovans: Known Mainly From DNA
Denisovans are one of the strangest entries on this list because we know more about their genetics than their physical appearance. For years, the entire fossil record consisted of just five tiny, fragmented bones from Denisova Cave in Siberia: a few worn molars, partial finger bones, and small bone chips. A jawbone found at Baishiya Cave in China was later identified as Denisovan through protein analysis.
What we lack in fossils, DNA has filled in. Denisovans split from a common ancestor with Neanderthals between 440,000 and 390,000 years ago, and the oldest securely dated Denisovan remains go back roughly 200,000 years. They appear to have been widespread across continental Asia, island Southeast Asia, and near Oceania. Modern humans encountered and interbred with at least two distinct Denisovan populations. Melanesian populations today carry the highest proportion of Denisovan DNA, at 4 to 6 percent. Lower amounts appear in other Southeast Asian and Pacific Islander groups.
In 2021, a large, thick-browed skull from Harbin, China, was named “Dragon Man” and proposed as a new species called Homo longi. Genetic material recovered from the skull has since confirmed it as Denisovan, finally giving researchers a better picture of what this elusive group looked like.
Homo Floresiensis: The “Hobbits”
Homo floresiensis was discovered on the Indonesian island of Flores and immediately earned the nickname “the hobbit.” A female skeleton stood just 3 feet 6 inches tall, and her brain was about a third the size of a modern human’s. Despite their tiny stature and small brains, they made stone tools and hunted small animals. How a human species became so small remains debated, though island dwarfism, a well-documented phenomenon where isolated populations shrink over generations, is a leading explanation.
Homo Naledi: Small Brains, Complex Behavior
Homo naledi was discovered in the Rising Star Cave system in South Africa, where the remains of more than 30 individuals were found in chambers that are extremely difficult to access. The fossils date to roughly 250,000 to 350,000 years ago. What makes Homo naledi remarkable is the combination of a very small brain, with volumes ranging from 450 to 610 milliliters (overlapping with much older, more ape-like ancestors and far smaller than our roughly 1,400 ml average), and behavior that looks surprisingly complex.
The placement of bodies deep inside the cave system suggests deliberate transport of the dead, something that, in modern humans, would be called mortuary behavior. If confirmed, this challenges the long-held assumption that complex symbolic behavior required a large brain.
Homo Heidelbergensis and Homo Habilis
Homo heidelbergensis lived in Africa and Europe and is widely considered the common ancestor of both Neanderthals and Homo sapiens. This species bridges the gap between the older Homo erectus and the more recent lineages that eventually led to us and our Neanderthal cousins.
Homo habilis, living roughly 2.4 to 1.4 million years ago, is one of the earliest members of our genus. Its name means “handy man,” a reference to the simple stone tools found alongside its fossils. Homo rudolfensis lived around the same time and is similar enough to Homo habilis that some researchers question whether they’re truly separate species.
Ghost Species We Haven’t Found Yet
DNA analysis has revealed the fingerprints of human species that left no known fossils at all. A 2020 study found that multiple West African populations carry genetic ancestry, averaging around 6 to 7 percent of their genomes, from an unknown archaic human population. This “ghost” population diverged from the ancestors of both modern humans and Neanderthals somewhere between 360,000 years and over a million years ago, and interbred with the ancestors of present-day West Africans within the last 124,000 years. We have no bones, no tools, and no name for this group. We only know they existed because their DNA survives in living people.
This discovery suggests the true number of human species is likely higher than what the fossil record shows. Africa in particular, where our own species evolved, almost certainly hosted more lineages than we’ve identified so far.
A Crowded Family Tree
For most of our evolutionary history, being the only human species on Earth was not normal. As recently as 100,000 years ago, Homo sapiens shared the planet with Neanderthals in Europe, Denisovans across Asia, possibly late-surviving Homo erectus in Southeast Asia, Homo floresiensis on Flores, and Homo naledi in southern Africa. Several of these groups met and interbred with us, leaving genetic legacies that influence human biology today, from immune function to altitude adaptation. Our current situation, one human species alone on the planet, is the exception rather than the rule.