The Third Chimpanzee Summary

How different are we really from our closest cousins, the chimpanzees? Understanding our shared traits and history could unlock answers to questions about human nature.

1. Humans and chimpanzees share surprising genetic similarities.

The bond between humans and chimpanzees runs deeper than the eye can see. Genetic research demonstrates that humans share an astounding 98.6% of their DNA with chimpanzees, making them our closest cousins. Even with gorillas and orangutans, the shared DNA percentages remain high, at 97.7% and 96.4%, respectively, emphasizing a shared ancestry.

This genetic overlap challenges traditional taxonomy, where chimpanzees and humans are classified into separate families. Advocates of cladistics suggest that humans and chimps should belong to the same genus, Homo. According to this view, the three species within this genus—Homo sapiens (humans), Homo troglodytes (common chimpanzees), and Homo paniscus (bonobos)—are closer relatives than many bird species sharing a genus.

Such closeness blurs the lines between us, yet the 1.4% DNA difference results in unique human traits. This small percentage allows for language, advanced technology, and art—defining characteristics that distinguish humans from even our closest relatives.

Examples

• Humans and chimps are genetically closer than chiffchaffs and willow warblers, which share 97.7% DNA but are in separate genera.
• Comparisons of larynx structures reveal a subtle human anatomical change responsible for speech.
• Advances in genome mapping verified humans' genetic links to primates with high precision.

2. The development of speech revolutionized human evolution.

The ability to speak was a transformational moment in human history. Speech gave Homo sapiens a decisive edge over other hominids, enabling more efficient communication of ideas, instructions, and stories. Language shaped art, culture, and technological innovation.

Three million years ago, our ancestors were already diverging from great apes. The species Australopithecus africanus and Australopithecus robustus emerged, followed by evolutionary developments to Homo habilis, Homo erectus, and eventually Homo sapiens. Despite these anatomical changes, the control of speech muscles—a larynx, tongue, and other structures—was absent for much of Homo sapiens' early existence.

Finally, around 40,000 years ago, humans underwent a "great leap forward." Anatomical alterations enabled complex vocalizations. Language now became a tool for advancing cooperation, resource management, and social bonding, marking a turning point in human evolution.

Examples

• Early Homo erectus expanded to Europe and Asia well before developing speech capabilities.
• Modern larynx placement allows humans, but not apes, to pronounce nuanced sounds necessary for language.
• Art and tools from 40,000 years ago coincide with archaeological evidence of speech emergence.

3. Early human languages likely formed like pidgins and creoles.

Human language did not emerge perfectly formed. Instead, ancient languages developed over time through improvisation and adaptation. Historical models, like pidgin languages born in trade hubs, demonstrate how human societies may have communicated in their earliest days.

Pidgins arose when people from different linguistic backgrounds met, such as during the European colonial era. These simplified languages combined basic vocabulary and rules from different tongues. Over generations, these pidgins transformed into creoles, incorporating a richer structure with more advanced grammar.

Interestingly, creoles around the world—from the Caribbean to Africa—share similarities despite geographical separations. These common traits reflect how humans naturally structure communication and provide a glimpse into the origins of the very first languages.

Examples

• Vervet monkeys demonstrate proto-language capabilities, using calls to signal specific predators.
• Subject-verb-object structures and prepositions are universal in creoles, mirroring early human speech patterns.
• Pidgins and creoles confirm humans' capacity for creating unified communication systems.

4. Human physical diversity evolved through natural and sexual selection.

Distinct racial characteristics, like skin tone or hair type, are the result of both natural and sexual selection. Natural selection emphasizes survival—traits that help humans adapt to their environments are passed down. For example, darker skin in sunny regions helps protect against UV damage.

However, natural selection does not explain every variation. Differences in hair or eye color may have developed due to sexual selection. In this process, traits deemed attractive within a group increase the odds of mating success, spreading those features over generations.

The interplay between natural and sexual selection likely shaped human diversity. Tall Andean natives, darker sun-exposed populations, and lighter pigmentation in northern regions all arose through both functional adaptation and social preferences across millennia.

Examples

• Large lungs in high-altitude communities help absorb thin oxygen.
• Blonde hair and light-colored eyes in Europe evolved as sexually desirable traits.
• Different shades of skin accommodate varying sunlight exposures worldwide.

5. The shift to agriculture diminished overall quality of life.

Contrary to popular belief, the transition from hunting and gathering to agriculture did not immediately improve life for early humans. Studies of hunter-gatherers suggest they had more leisure time and healthier diets compared to early farming communities.

Hunter-gatherer skeletons from Turkey and Greece, dated to the Ice Age, show these individuals were taller and healthier than agricultural societies that succeeded them. Meanwhile, evidence from Kalahari bushmen today shows that subsistence living can require fewer work hours than farming.

Farming populations grew larger thanks to stable food supplies. However, this size advantage came at the cost of health and more grueling labor. Over time, agriculture's ability to sustain higher populations made it dominant, paving the way for technological advancements and societal complexity.

Examples

• Pre-agriculture humans averaged 172 cm in height, dropping to 157 cm as farmers.
• Modern Kalahari bushmen work fewer hours acquiring food than most farmers.
• Rapid population growth favored farming societies despite initial drawbacks.

6. Genocide is a recurring, disturbing part of human history.

Genocide is not an anomaly committed by "monsters." Research shows it is a recurring pattern across human history, driven by territorial disputes, racism, religion, and politics. Often, perpetrators rationalize such killings by dehumanizing victims.

The 26 documented genocides of the 20th century include the Armenian massacres in Turkey and the Rwandan genocide, where over 800,000 Tutsi were killed. In many cases, economic and population pressures fueled such atrocities.

Understanding genocide as deeply rooted in human tendencies—not limited to unique instances—may help people recognize and prevent future tragedies.

Examples

• The Tasmanian Aboriginal population fell from 5,000 to three due to British settlers by 1869.
• Hutu leaders framed the Tutsi as a threat in pre-1994 Rwanda, sparking mass killings.
• Dehumanization strategies, like referring to victims as "rats," justify genocidal acts.

7. Humans have always altered—and sometimes destroyed—the environment.

The idea of humans living harmoniously with nature is a myth. Throughout history, societies have exploited their environments, often with catastrophic results. This reinforces that environmental destruction is not a modern issue but part of humanity's long-standing behavior.

Consider the Māori in New Zealand, who hunted the moa bird to extinction for food and tools. Another example is the Ancient Ones of New Mexico, who clear-cut woodlands around their settlements. Without trees, their irrigation systems failed, dooming their societal infrastructure.

Today's environmental challenges aren’t new. But unlike our ancestors, modern societies are fully aware of the consequences of unsustainable practices.

Examples

• Moa skeletons found in archaeological sites reveal human hunting habits.
• 100,000 years of hunting reshaped global animal populations.
• The deforestation-caused collapse of the Ancient Ones highlights resource dependency.

8. Human technological progress leapt forward with larger populations.

With agriculture came larger human populations. More people meant more innovation, as societies had the numbers to experiment with new ideas or technologies. This population growth simplified building civilizations.

Technological breakthroughs—from metalworking to written language—were supported by denser agricultural communities. While hunter-gatherers were healthier and less encumbered, their smaller numbers limited the ability to create and sustain significant advancements.

Human history illustrates that there are trade-offs: larger populations fueled creativity but required more from their environment to sustain development.

Examples

• Early agricultural societies pioneered irrigation systems supporting large populations.
• Written communication emerged when agricultural trade increased.
• Hunter-gatherer innovation rates lagged behind farming civilizations due to limited size.

9. Understanding human evolution fosters empathy and responsibility.

Examining our shared roots with other species reveals the astonishing complexity and shared traits that make us human. But this same understanding also highlights behaviors—like violence or environmental damage—that we need to address.

By reflecting on our evolutionary past, individuals and societies might develop perspectives that promote both collaboration and conservation. It reminds us that human potential for good can outweigh destructive tendencies when properly aligned with understanding.

Examples

• Genetic studies reveal our ability to cooperate stems from primate heritage.
• Observing genocide patterns motivates social efforts to counteract dehumanization.
• Past environmental damage serves as a cautionary tale for current practices.

Takeaways

1. Spend time in nature to appreciate alternative ways humans have interacted with the environment throughout history.
2. Reflect on how small personal choices, like supporting conservation efforts, connect to humanity's broader behaviors.
3. Commit to learning from history—its triumphs and disasters—to make informed decisions for the future.