10 Indispensable Scientific Discoveries That Have Shaped Human Survival

Essential Insights

Humans are truly remarkable beings. Over millions of years, we've not only survived but thrived, growing to a population exceeding 7 billion and spreading across the globe. This is despite our inherent vulnerabilities: we lack physical strength, protective fur, or resilience against harsh environments. Our survival depends on regular access to food and water, and we remain susceptible to numerous infectious diseases.

What has allowed humanity to flourish to the extent that we no longer spend every moment fearing for our survival? The answer lies in our advanced brain, which empowers us to innovate, imagine, and collaborate on brilliant solutions to life-threatening problems. While countless inventions support modern life, some are so crucial that living without them would be nearly impossible.

10: The Wheel

The phrase "no need to reinvent the wheel" underscores the wheel's profound impact on human progress. This simple yet transformative invention revolutionized daily life, making it hard to imagine how humanity survived without it for so long.

Archaeologists continue to debate the wheel's origins. The earliest traces date back to around 3500 B.C.E. in Mesopotamia, where it was initially used for pottery rather than transportation. It wasn’t until roughly 300 years later that its potential for moving goods and people was fully realized [source: Gambino].

The evolution of the wheel unfolded in several phases, starting with logs used as rollers to ease the movement of heavy objects and progressing to wheels mounted on axles for smoother rotation [source: ThinkQuest]. By 2000 B.C.E., wheeled chariots with spoked wheels, which were both lighter and more durable, became prominent in ancient Egypt.

The wheel stands as arguably the most pivotal mechanical invention in history. Its influence permeates nearly every modern mechanical device, from cars and bicycles to factory equipment, toys, and even wristwatches. Beyond machinery, the wheel remains essential for pottery and transporting goods, applications that ancient civilizations undoubtedly valued.

9: Blade

While the wheel undoubtedly revolutionized ancient life, it couldn't replace the blade for tasks like hunting boars or skinning bears. As Crocodile Dundee famously quipped, "That's not a knife."

This brings us to the blade—and its various forms like the axe, knife, and others—as a life-saving innovation for humanity. Recent studies reveal that stone tools, including blades, not only improved human diets and clothing but also played a role in shaping the functionality of our hands 1.7 million years ago [source: Reardon].

Long before that, early humans relied on sharp stone flakes and hand axes to process meat. A 2012 excavation in Ethiopia's Afar region revealed that human ancestors were using butchering tools as far back as 3.4 million years ago [source: Viegas].

8: Clothing

The first major shift in human fashion was the loss of fur. While bare skin is trendy today, it wasn't always the norm. Scientists believe humans shed their fur around a million years ago to prevent brain overheating. Sweating became a more efficient cooling mechanism without the hindrance of thick fur [source: Connor].

After shedding our body sweaters, humans faced increased vulnerability to harsh weather, necessitating the use of clothing. Pinpointing the exact moment clothing was adopted is challenging, as animal hides, often used for garments, decompose over time [source: Upton]. (Additionally, hides served purposes beyond clothing, such as shelter.)

Researchers at the University of Florida conducted an innovative study to determine when clothing lice diverged genetically from head lice [source: Toups et al.]. (Yes, the two are distinct.) Their findings suggest that clothing lice emerged between 83,000 and 170,000 years ago, coinciding with an ice age and the likely advent of clothing. While humans enjoyed millennia of nudity, clothing—whether fur or fabric—has since been a lifesaver countless times [source: Viegas].

7: Shelter

With wheels, blades, and clothing in hand, early humans needed a way to store and protect their innovations. Carrying everything around wasn't practical, so another breakthrough was essential—not just for convenience but for survival. (And no, these discoveries didn't happen in that specific order.)

When it comes to shelter, it's important to recognize that this isn't an exclusive human innovation. Initially, humans followed the same path as many animals, seeking out safe hiding spots. For our ancient predecessors, this likely included tree nests. Naturally, caves and rocky overhangs were also favored locations.

Evidence suggests that as far back as 2.6 million years, early human communities were gathering food and tools, transporting them to preferred locations such as watering holes or resting areas [source: Smithsonian]. Around 800,000 years ago, the use of fire and hearths became evident. The oldest proof of constructed shelters dates back 400,000 years, with archaeological findings like postholes in Terra Amata, France [source: Smithsonian]. These shelters reduced human vulnerability to environmental challenges, enhancing survival in tough climates.

6: Sewage Disposal

Advancing to more recent history, a pivotal lifesaving development emerges. In a survey conducted by the British Medical Journal, experts and readers were asked to identify the top scientific breakthrough of the past 150 years. Surprisingly, it wasn't groundbreaking surgeries or digital conveniences. The clear winner was improvements in sanitation, surpassing even antibiotics and anesthesia in importance [source: Katz].

The realization that managing human waste could prevent deaths is relatively recent. In Victorian England, where the Thames River was overwhelmed with filth and streets were flooded with sewage, Edwin Chadwick, a former journalist and lawyer, championed the idea that sanitation could prevent diseases like typhus, cholera, and influenza, which thrived in such unsanitary conditions.

Chadwick proposed designs for hydraulic sewage systems and drainage pumps to eliminate waste, some of which directed sewage straight into the Thames. Despite progress, proper waste disposal remains a global challenge: one billion people, or 15% of the global population, still defecate openly, and 2.4 billion rely on inadequate sanitation facilities as of 2015 [source: WHO/UNICEF].

5: Water Purification

Contaminated water doesn't just cause discomfort like stomach pain and diarrhea, as many travelers to developing nations can confirm. Waterborne illnesses are deadly, with the World Health Organization reporting in 2005 that they are the leading cause of death, responsible for 3.4 million lives lost each year—more than war, terrorism, and weapons of mass destruction combined. Malnourished children in poor countries, with already weakened immune systems, are especially vulnerable [source: VOA].

In the past, the situation was far more dire. For centuries, even in advanced nations, unexplained and recurring cholera outbreaks, caused by water contamination, claimed thousands of lives [source: Encyclopaedia Britannica]. During the 1854 cholera epidemic, British researcher John Snow identified sewage-borne microorganisms as the culprit. He introduced the revolutionary idea of using chlorine to purify water, drastically reducing illness rates. Since then, advancements in chemical treatments and filtration have significantly improved water safety [source: Lenntech].

4: Fire

The origins of fire mastery remain a mystery, but around 790,000 years ago, individuals in Africa's Acheulian culture learned to create, control, and utilize fire. This mastery of combustion, as evidenced by findings from an Israeli archaeological team led by Nira Alperson-Afil, was crucial for human survival and migration [source: Hebrew University of Jerusalem].

Fire provided early humans with a powerful tool: flaming torches to ward off predators and protect their young. It also offered warmth, enabling survival in colder climates. Additionally, cooking expanded food options, preventing malnutrition. More than any other innovation, fire allowed humans to thrive and populate the globe.

While we no longer huddle around fires or feast on charred mammoth meat, the ability to harness and burn fuel remains essential to our survival and progress.

3: Agricultural Crops

Without farming to supply food, we would all be forced to live like ancient hunter-gatherers, spending most of our time foraging and hunting. While this lifestyle has its merits, such as adaptability and efficient resource use across diverse environments, it would require constant movement and limit group sizes. Modern society, with its militaries, factories, and shopping centers, would be impossible without agriculture, making its development vital to our survival.

Agriculture represents a series of scientific and technical innovations, including irrigation technologies, crop rotation, and fertilizers, developed over millennia. It began when humans learned to collect seeds from wild plants, cultivate them, and harvest the results. DNA studies of modern crops trace the origins of staple foods like wheat, barley, chickpeas, lentils, and flax back 9,000 to 10,000 years in southwest Asia [source: Harris].

2: Antibiotics

Throughout much of history, bacterial epidemics posed a deadly threat to populations worldwide. The bubonic plague, or "Black Death," for instance, claimed around 200 million lives in the 14th century alone [source: BBC].

In the late 1920s, Dr. Alexander Fleming, a London-based physician, discovered that mold contaminating a petri dish prevented the growth of a pathogen he was studying. His findings, published in 1929, led to the development of penicillin by his student, Dr. Cecil Paine, who first demonstrated its effectiveness in treating bacterial infections in humans [source: Wong]. Since then, antibiotics like penicillin have drastically reduced mortality rates from diseases such as syphilis, septicemia, and bubonic plague [source: Hemminki and Paakkulainen]. However, other advancements, such as clean water systems, have also contributed to this decline [source: Hemminki and Paakkulainen].

1: Food Preservation

The cans of refried beans in your cupboard may seem like a simple innovation, but they play a critical role in survival during emergencies. Preserving foodstuffs without refrigeration allows people to endure disasters that disrupt electrical grids and access to fresh food.

Canning emerged in the late 18th century as a solution to military challenges. Napoleon's army faced more deaths from starvation and scurvy than from battle, prompting the French government to offer a 12,000-franc reward for a food preservation method [source: Can Manufacturers Institute]. Nicholas Appert, a Parisian with experience as a candy maker, chef, and beer brewer, devised a technique involving partially cooking food, sealing it in corked bottles, and boiling them to remove air, which he believed caused spoilage. (Louis Pasteur later proved that heat killed microorganisms responsible for spoilage and disease.)

French soldiers tested Appert's preserved poultry, vegetables, and gravy during a four-month voyage and found the food still edible. In 1810, Peter Durand patented an improved container with a soldered lid, and by 1812, Bryan Donkin and John Hall established a factory to produce food in metal cans [source: Can Manufacturers Institute].