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Seven Discoveries that Changed the Course of Human Evolution

rafting

The best early evidence of a modern human voyage across large stretches of open water is the colonisation of Australia at least 50,000 years ago, navigating 50–90 km stretches of water where land could not be seen. Credit: Jamie Tufrey

By Paul Taçon

Seven discoveries made by our ancient ancestors were key cultural drivers that changed the course of human evolution in extraordinary ways.

When we ask people what they think are the top discoveries or inventions that transformed human evolution we get an interesting range of responses. Many people focus on things from relatively recent times, from cars to computers, the discovery of electricity or maybe the atom, from agriculture to the cotton gin, and even sliced bread and bottled beer!

But there are much earlier discoveries that led to all of these, as well as to understanding who we are as 21st century modern humans who are distinctly different from our earliest ancestors and other creatures.

Human evolution has always been shaped by the environment and environmental change, but over the past few million years culture has played an increasingly prominent role. But what were the key cultural drivers that helped transform our archaic ancestors into us? I argue that seven pivotal discoveries by our ancient ancestors changed the course of their and our evolution in what would have been unimaginable ways.

1. Stone Tools

Our earliest human ancestors in Africa probably initially used a few basic wooden tools for foraging, primarily some form of stick. For instance, both chimps and gorillas have been observed using sticks to get food and for other purposes.

Unfortunately, early wooden tools do not survive in the archaeological record, but an early ancestral woman could easily have fashioned the first “digging stick” from a tree branch, allowing her to access underground tubers and to ward off overly aggressive males. Once stone was used for tools the world of our ancient ancestors was set on a totally new course.

The oldest evidence of stone tool use comes from Ethiopia, and dates to about 3.4 million years ago. Bones with cut marks similar to those made when stone is used to carve off meat and percussion marks suggestive of marrow extraction were found, leading to the conclusion that Australopithecines similar to the famous “Lucy” both made stone tools and ate meat. However, the oldest unambiguous evidence of stone tool use, in the form of the tools themselves, dates to about 2.6 million years ago and comes from another part of Ethiopia.

Whenever stone tools were first made, they soon transformed the diet of our earliest ancestors as more protein could be consumed, which was beneficial to the brain. And stone tools were useful for making an increasing range of wooden and bone tools that allowed archaic humans to better exploit new environments and food resources. Sharp-edged stone artefacts could also be used for cutting animal skins and tendons to make leather strips for tying, hides and eventually clothing.

2. The Baby Sling

Unlike artefacts made of stone, organic material does not survive long in the archaeological record, but animal skin could have easily been tied to form a pouch to be suspended from the neck or shoulders for carrying babies. Archaeologist Timothy Taylor argues that this occurred at least 1.8 million years ago, and possibly as early as 2.2 million years ago. Besides allowing parents greater ease of movement, it made long distance travel possible, helping Homo erectus to reach Indonesia on Australia’s doorstep.

Taylor suggests the baby sling gave babies an extended period of helplessness outside the womb, allowing them to take in information about the world from a calm and safe environment, much like kangaroo joeys in their mother’s pouches.

Babies thrived in the calmness of gently rocking slings, with their energy focused toward physical and behavioural development. This promoted brain development, resulting in increasingly smarter offspring who were better able to cope with the challenges of new or changing environments.

3. Control of Fire

At least a million years ago fire was purposely controlled and probably used for cooking, as suggested by evidence discovered in 2012 at Wonderwerk Cave in South Africa. Some scientists believe it might have begun as much as 1.8 million years ago with Homo erectus, as Richard Wrangham proposed in 1999. However, undisputable evidence of the use of fire for cooking dates to 400,000 years ago and is associated with the common ancestor of Neanderthals and modern humans.

Cooking made food more digestible, easier to chew and safer to eat, and gave ancient humans more calories in their diet. And better diet equals better brain development.

Fire could also be used for warmth, warding off predators and managing landscapes (as Aboriginal Australians have done for thousands of years). Eventually, the controlled use of fire developed into the fuel industries that power manufacturing today, trips to outer space and our daily lives. Cooking has also gone on to define cultures worldwide.

4. Watercraft

Cooking, stone tools and baby slings all would have increased cognition, leading to many more discoveries and inventions, including how to travel across water. The oldest surviving boat is the “Pesse canoe”, a dugout made from a hollowed tree trunk found in The Netherlands. It is about 10,000 years old but it is unlikely that ancient watercraft would last much longer so we do not know exactly when they were first invented.

Homo erectus was probably the first to create some form of sea-faring vessel. Perhaps it began with crude rafts made from bundles of reeds or logs lashed together to travel short distances along creeks and rivers, but coastal regions might also have been colonised this way as much as 1.8 million years ago.

The best indirect evidence of ancient sea journeys comes from stone tools of the type used by Homo erectus on the island of Flores, Indonesia. These tools date to about 800,000 years ago, and to reach Flores required crossing three channels, the widest about 19 km.

Neanderthal tools believed to be more than 100,000 years old from the Mediterranean island of Crete suggest they journeyed over water as well. Some archaeologists, such as George Ferentinos, have concluded this indicates Neanderthals made some type of boat with sails. The best early evidence of a modern human voyage across large stretches of open water is the colonisation of Australia at least 50,000 years ago, navigating 50–90 km stretches of water where land could not be seen.

The mastering of long ocean voyages eventually led to the colonisation of the Pacific. It also underpinned a human desire to travel long distances quickly, leading to new forms of land transport, the tall ships of former European and Asian empires and eventually motor vehicles, aircraft and ships for travel beyond the Earth.

5. Picture-Making

None of this could have happened without plans and pictures. The earliest accepted human-made design was recovered from Blombos Cave in South Africa. It consists of engraved lines arranged in geometric patterns on pieces of red ochre about 75,000–77,000 years old.

In 2012, a red disc painted on the wall of the El Castillo rock art site in northern Spain was assigned a minimum age of about 40,000 years and a hand stencil to about 36,000 years.

In October 2014, uranium-series dating expert Maxime Aubert and his team shocked the world with definitive evidence of equally old rock art in Sulawesi, Indonesia. There a hand stencil has a minimum age of 40,000 years and naturalistic paintings of animals are at least 35,000 years of age.

This suggests that figurative painting most likely began tens of thousands of years earlier in Africa and that modern humans brought the practice to both Europe and South-East Asia, and then to Australia.

Art is a powerful communication tool that can be used to tell stories and convey experiences, memory and history. It involves creativity and imagination, but can be used to express social change, religious belief, political viewpoints, conflict, change and emotion.

The creation of art and its placement in enduring landscape locations allowed ancient humans to convey information outside their brains. This “symbolic storage” revolutionised the way humans passed on knowledge,

leading to full-blown modern human culture as we know it, and eventually to great art traditions, books, television and iPads.

6. Domestication of the Dog

The transformation of wolves into dogs changed the human world in many unexpected ways. Some researchers suggest this occurred at varying times in places as widespread as South-East Asia/China, the Middle East, central Asia, Europe and even Africa and the Americas, or some combination thereof.

However, archaeological evidence for dog domestication is much more recent, with the earliest potential physical evidence for large dogs from the Altai Mountains of Siberia about 33,000 years ago and Goyet, Belgium, close to 31,700 years ago. The footprints of a large canid argued to be part-wolf, part-dog were found alongside those of an 8–10-year-old boy along a 50-metre tunnel floor in Chauvet Cave, southern France, when the cave’s famous rock art was documented. Soot and smudge marks left by the boy’s torch have been dated to 25,000–26,000 years ago. This could be the earliest surviving evidence of a close human/wolf-dog relationship.

This relationship continues today in many different forms, from protection to companionship, from helping with hunting to mobile garbage disposal. Certainly dogs gave early humans a competitive advantage over those without them. Most importantly, the process of domesticating wolves into dogs eventually led to other animals and plants being domesticated. Full-blown agriculture then propelled our ancestors in a totally new direction, forever changing the planet in the process.

7. Mathematics

Once our early hunter-gatherer ancestors began to perform basic counting, perhaps on their fingers, new possibilities emerged. When they first recorded tallies is another matter, but some people argue that engraved ochre pieces in Blombos Cave may be the earliest evidence. Other suggestions include early geometric rock art designs and notched bones in Europe, but the most convincing is the Ishango bone.

This engraved bone tool from the headwaters of the Nile is about 20,000 years old and has a series of engraved lines that look like tally marks. These lines have been interpreted as sequences of prime numbers or some sort of lunar calendar. One end has a piece of quartz embedded in it, perhaps for making further tally marks or mathematical deductions on other materials.

In a brilliant book called How Mathematics Happened: The First 50,000 Years, Peter Rudman shows how rudimentary counting developed into the complex mathematical systems of the ancient Egyptians, Babylonians, Greeks, Chinese and other peoples. From these, the global mathematical system we use today formed, laying the foundation for computers, iPhones and everything we take for granted in our digital era of human existence.

Summary and Conclusions

These seven discoveries made by our ancestors at different times in the past underpin all subsequent major human discoveries and inventions. Stone tools allowed us to make new wooden tools, and both led to the harvesting of new food resources, while fire enabled us to cook them. More varied and nutritious food fired up our ancestors’ brains, leading to new inventions for survival. Baby slings allowed ancient people to move great distances much more easily, eventually leading to long journeys out of Africa by both archaic and modern human groups. Watercraft, at first basic rafts but later more complex vessels, allowed early humans to travel across water as well as land, giving access to new resources such as deep water fish as well as enabling fast journeys over great distances, such as the first human voyages to Australia. Watercraft as transport eventually led to the wheel, trains, motor vehicles and aircraft.

The capacity to make pictures, symbols and representational systems changed the way early modern humans passed on information from one person to the next, and from one generation to the next. The production of art more than 77,000 years ago and rock art at least 40,000 years ago underpins every way we have communicated with each other since.

Once people learned to domesticate the dog it was an easy next step to domesticate other animals and plants. Subsequent agriculture totally transformed the human world – from hunter-gatherers living a mobile existence to peoples tied to the land, eventually constructing and settling in villages, towns and cities. The dog helped transform humans in many other ways, and today is considered part of the human family for many people.

Mathematics underpins everything in the digital world we live in today. Along with picture-making it gives us iPhones,

television, computers and the ability to travel deep into outer space. Interestingly, the first animal to orbit the Earth was Laika, a dog. There is a strong relationship between mathematics, astronomy and music, and through music and song humans have long reinforced and passed on the most important aspects of human existence and experience, often in combination with pictures and performance.

There may be new discoveries in the future that will be equally revolutionary but we have to look at the world of science fiction to imagine what they may be – for instance, a time machine, encounters with aliens, a human-induced apocalypse or a way of living outside our physical bodies. But then we might no longer be human as we know it!

Paul Taçon is Chair in Rock Art Research and Director of the Place, Evolution and Rock Art Heritage Unit in Griffith University’s School of Humanities.