For Intro to Anthropology, we read the second part of Chapter 6, “The Other Humans and Us” (sections 6.3-6.4) from The Human Story (Commissions earned). This follows our discussion of human origins and dispersal.
Key Concepts: What Happened to the Neanderthals
- At 40,000 years ago, Neandertals and Homo sapiens were more like each other than either is like us. The “us” in “the other humans and us” is a trap—we’ve kept evolving too, so don’t picture modern people interbreeding with Neandertals (184).
- Neandertals were not dumb, and not our ancestors. They emerged ~400,000 years ago, ranged across cold Europe and western Asia until ~35,000 years ago, controlled fire, and made their own Mousterian tools—a separate lineage, not a rung below us (184-186).
- Bigger brains ≠ smarter. Neandertal brains were larger on average, likely a scaling effect of stockier bodies. Organization and complexity matter more than raw size (185).
- They had symbolic culture. Body paint, shell and bone jewelry, possible intentional burial, and care for group members who couldn’t contribute—behaviors shared with contemporary Homo sapiens (186).
- What limited them was connection, not intelligence. Smaller groups, more local material sourcing, no clear fitted clothing, and far less long-distance trade than Homo sapiens.
- Denisovans were discovered through DNA. Known mainly from a few bones in Denisova Cave, Siberia; genetics shows a cousin lineage to Neandertals, sharing a common ancestor ~450,000 years ago (186).
- The other humans are literally still part of us. Many people carry 1-4% Neandertal DNA, and some populations carry Denisovan DNA, through a process called introgression (187-190).
- Don’t overread that DNA. Most introgressed genes sit outside coding regions; claims that Neandertal DNA causes specific modern conditions outrun the evidence.
- Other Homo experiments ran in parallel. Homo naledi (small-brained, sophisticated, South Africa) and Homo floresiensis (the “hobbits,” product of insular dwarfism on Flores)—no evidence either interbred with us (188).
- Extinction of the fittest. Gigantopithecus, Paranthropus, and the Neandertals were all well-adapted and all went extinct. What carried Homo sapiens through was flexibility, diversity, and interconnection—survival of the generalist (191).
The Other Humans Were More Like Us Than We Think
The textbook calls this section “The Other Humans and Us” (184), but that framing requires a caution. If we rewound the clock to 40,000 years ago, we wouldn’t look at early Homo sapiens and think “that’s my team” while rejecting Neandertals. Both would seem strange to us. The Neandertals and Homo sapiens of that era were more similar to each other—genetically and behaviorally—than either would be to modern humans. We’ve been changing and evolving too. It’s the same trap as saying “we became bipedal”: we didn’t—some creatures that looked nothing like us did, and we descend from them. We should be just as careful not to project ourselves back onto the Homo sapiens of 40,000 years ago.
When Homo sapiens emerged from Africa around 200,000 years ago and spread into other regions, they encountered a world with multiple intelligent bipedal species. Today we interact only with other Homo sapiens—we’re a genetically very similar species. But early Homo sapiens would have encountered Neandertals, Denisovans, and possibly other groups we haven’t yet identified. The differences we now call races and ethnicities emerged only in the last 40-50,000 years, after all these other human species had disappeared.
Neandertals: Not Dumb, Not Our Ancestors
Neandertals are the most famous of our close relatives (184-186). They emerged from Homo erectus populations around 400,000 years ago and lived across Europe and western Asia until about 35,000 years ago. The name comes from the Neander Valley (“Tal” in German) in Germany where the first skeletons were discovered. Early researchers thought they were directly ancestral to modern humans, but genetic evidence shows they were not—they coexisted with Homo sapiens as a separate lineage, weirdly close to us but not us.
Despite the stereotype of the “dumb Neandertal,” their brains were actually larger on average than Homo sapiens brains (185). This doesn’t mean they were smarter—the size difference is likely a scaling effect related to their larger, stockier bodies rather than an indication of superior cognition. Having a big brain doesn’t automatically do anything for you; Homo sapiens made it and Neandertals didn’t. But they were certainly intelligent. They controlled fire, cooked food, hunted effectively, and developed their own distinctive Mousterian tool style.
There’s evidence they may have buried their dead intentionally—though this is debated—and cared for injured group members rather than abandoning them (186). They made body decorations, jewelry, beadwork, and bone necklaces, suggesting some form of symbolic capacity and perhaps a sense of self. This care for non-contributing members appears among Homo sapiens of the period too: some of the earliest Homo sapiens burials are of people who would today be considered disabled, who lived longer than they could have without care. Whether Neandertals learned some of these practices from Homo sapiens, developed them independently, or even taught Homo sapiens, remains debated.
What Limited the Neandertals?
If Neandertals were so capable, why did they disappear while Homo sapiens survived? Part of the answer is that we never know for certain why one lineage persists and another doesn’t—it can come down to luck. But several factors seem relevant. Neandertals had smaller population sizes and more limited movement across their range. The materials they used for tools typically came from within a few miles of where they lived—they didn’t trade over long distances the way Homo sapiens did from the beginning.
We also don’t see evidence of fitted clothing among Neandertals. How do we know Homo sapiens wore fitted clothing? From lice. Around 83,000 years ago, head lice and body lice diverged into separate species, and body lice can only survive in clothing. Neandertals probably used animal skins for warmth, but the stitched, fitted garments that allowed Homo sapiens to thrive in extreme climates seem to have been a Homo sapiens innovation.
The Neandertals were well-adapted to cold climates—perhaps too well-adapted. When environments shifted, their specialization may have become a liability. This pattern appears throughout evolution: sometimes the “fittest” go extinct precisely because they’re so well-suited to conditions that no longer exist.
Denisovans: Discovered Through DNA
The Denisovans represent a remarkable scientific discovery (186). We know they existed primarily through genetic analysis of a few bones found in Denisova Cave in Siberia—not through extensive fossil or archaeological evidence. In an earlier era those bones might simply have been lumped in with the Neandertals. DNA analysis instead revealed a distinct sequence: a cousin group to the Neandertals, sharing a common ancestor from around 450,000 years ago. While Neandertals lived mainly in western Eurasia, Denisovans seem to have inhabited the eastern part of the range. The research is still emerging, and the picture may be revised as more evidence appears.
Genetic Introgression: They’re Still Part of Us
For a long time, the assimilation model suggested Homo sapiens simply replaced other human species without interbreeding. More sophisticated genetic analysis—emerging only about 15 years ago—revealed a more complex picture (187). There was interbreeding: with Neandertals, Denisovans, and probably other groups we haven’t yet identified.
People with ancestry across Europe and Asia carry from 1 to 4% Neandertal DNA. Most of this interbreeding probably occurred in what is now the Middle East, where Homo sapiens and Neandertals coexisted—which fits the fact that Neandertal DNA later shows up in both Europe and Asia. Denisovan DNA appears most prominently in populations from Oceania and Southeast Asia.
This mixing occurred through a process called genetic introgression (190)—sporadic interbreeding over time that leaves marks in the DNA even though the gene pools never fully merged. The other humans are literally still part of us (188). We are genetic mosaics carrying traces of these ancient encounters.
Since this evidence emerged, people have made all kinds of claims—that Neandertal DNA causes asthma, or susceptibility to particular illnesses. These claims outrun the evidence. Most of the genetic material we carry from Neandertals and Denisovans lies outside the coding regions that determine traits like language or cognition, and whether you carry it doesn’t influence your capacity to be human. It may shape some other traits; we don’t yet know.
Other Human Species: Hobbits and More
Several other Homo species existed during this period, though there’s no evidence of genetic mixing with Homo sapiens.
Homo naledi (188) was a small-bodied, small-brained species that lived in South Africa around 230,000-340,000 years ago. Some of the most complete hominin skeletons ever discovered belong to this species. They display a mosaic of traits—some Homo sapiens-like features combined with more archaic elements—and there is debate over whether they intentionally buried their dead, which would be striking for such small-brained creatures. There’s no evidence they interbred with Homo sapiens, though they may have overlapped with other emerging Homo types.
Homo floresiensis (188), nicknamed “the Hobbits,” were discovered on Flores island in Indonesia. Standing about three feet tall with small brains, they appear to be descendants of an early Homo erectus migration who became isolated on the island. Their small size likely resulted from insular dwarfism—an evolutionary process where island-bound populations shrink over generations, the same way large mainland elephants can give rise to dwarf island elephants. They could apparently hunt small animals and perhaps use fire, and they survived until relatively recently.
These species remind us that human evolution wasn’t a single line of progress. Multiple experiments in being human occurred simultaneously across different regions.
Extinction of the Fittest
We often hear about “survival of the fittest,” but evolution frequently produces what might better be called extinction of the fittest. Rewind the clock and ask which creatures you’d bet on. At the time of the dinosaurs you’d have bet on dinosaurs over the small mammals—then an asteroid changed the conditions. Consider Gigantopithecus, a massive ape that lived in China around 300,000 years ago, big and strong and well-adapted; you’d have picked it to win, but it went extinct, leaving teeth that survived only because the rest was eaten. The robust australopithecines (Paranthropus) were bipedal, powerful-jawed, and superbly adapted to their environment for a very long run—and went extinct when that environment changed.
The Neandertals themselves were bigger, stronger, and better adapted to cold climates than Homo sapiens. Encountering them, you might have bet against the comparatively puny Homo sapiens. They went extinct, and we didn’t. Being well-adapted to current conditions can become a liability when conditions change.
Evolutionary Lessons for Our Future
The textbook ends with “From Our Pasts to Our Futures” (191), asking what lessons evolution offers. Environments have always changed and will continue changing—we face unprecedented climate shifts ahead. Homo sapiens have adapted to many climate changes before, and there’s reason for cautious optimism. But that hope depends on learning the right lessons from our evolutionary past.
Which creatures survived? Not necessarily the biggest or strongest or most specialized. What human beings excel at, some have argued, is survival of the generalist—the capacity to learn many things, adapt, and avoid over-specialization, the value of a broad, general education. The survivors were those most open to change and flexibility, those who maintained diversity and varied perspectives, and those who stayed interconnected.
Migration has been central to human success from the beginning. When populations get cut off and isolated, they tend to struggle—resources fail, and there’s no one to trade with or learn from. The Neandertals’ more limited movement and smaller trade networks may have contributed to their disappearance. Homo sapiens, by contrast, traded genes and goods and ideas across vast distances from the very beginning. That interconnection—not isolation—characterized our species’ expansion.
When we think about building resilient societies for the challenges ahead—a crowded world, climate change, weapons that can destroy whole populations—evolution offers clear guidance: value flexibility over rigid adaptation, diversity over homogeneity, connection over isolation, movement over boundaries. The species that survived weren’t the ones that stayed put and kept to themselves. We might ask which societies today are embracing those lessons, and what the alternative sets us up for.
Frequently Asked Questions
What happened to the Neandertals?
They went extinct around 35,000 years ago, but not because they were unintelligent—they controlled fire, made Mousterian tools, and had symbolic culture. The likely factors were smaller populations, limited movement, no fitted clothing, and far less long-distance trade than Homo sapiens. Specialization to cold climates may have become a liability when conditions shifted (184-186).
Did humans interbreed with Neandertals?
Yes. Many people of Eurasian ancestry carry 1-4% Neandertal DNA, and some populations carry Denisovan DNA, through a process called introgression. Most of this interbreeding likely occurred in the Middle East. But the gene pools never fully merged, and most introgressed DNA lies outside the regions that shape traits like cognition (187-190).
Who were the Denisovans?
The Denisovans were a cousin lineage to the Neandertals, identified primarily through DNA from a few bones in Denisova Cave, Siberia. They shared a common ancestor with Neandertals around 450,000 years ago and seem to have lived across eastern Eurasia. The evidence is still emerging (186).
Are Neandertals our ancestors?
No. We descend from Homo sapiens, and Neandertals were a separate lineage that coexisted with us. We carry some Neandertal DNA from interbreeding, but they are cousins, not direct ancestors—and at 40,000 years ago, Neandertals and Homo sapiens were more like each other than either is like people today (184).
What is “extinction of the fittest”?
It’s the observation that being superbly adapted to current conditions can be a liability when conditions change. Gigantopithecus, Paranthropus, and the cold-adapted Neandertals were all well-suited to their environments and all went extinct. Homo sapiens survived through flexibility, diversity, and interconnection—”survival of the generalist” (191).
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