A tiny sliver of crystal quartz no larger than a raisin has shed extraordinary new light on the unique adaptations that set humans apart from all other primates.
Though tool-use has long been hailed as trademark of humanity, we’re not the only species to do this; chimpanzees and macaques, for example, are known to use rocks to smash apart hard objects such as nuts or oyster shells.
But, our fixation on miniaturization is unlike anything seen elsewhere in the primate family tree.
Experts say the crystal quartz flake found at Boomplaas Cave in South Africa and previously dismissed as waste was likely a poisoned arrowhead used to take down small prey such as hares and tortoises 17,000 years ago.
The remarkable discovery of the tiny tool indicates our ancestors were not simple-minded brutes, but ‘masters of aerodynamics,’ highlighting a key milestone in human evolution.
A tiny sliver of crystal quartz no larger than a raisin has shed extraordinary new light on the unique adaptations that set humans apart from all other primates. According to the researcher, this tip could have been laced with poison and affixed to an arrow shaft
WHY HUMANS MADE TINY TOOLS
Researchers have traced the miniaturization of technology as far back as 2.6 million years ago.
The development of high-speed weaponry, such as the bow and arrow, played a key role in changing tool size.
These weapons required lightweight stone tips in order to succeed.
Changing climate and scarcity of resources also played a role, researchers say.
Human ancestors may have started making tools smaller and more efficient as a way to conserve their resources.
Toward the end of the Ice Age, humans were also hunting smaller prey, such as hares and tortoises.
Smaller tools allowed them to be mobile and take down prey with greater efficiency.
Hominin technology experienced at least three waves of miniaturization, with the first occurring at about 2.6 million years ago, according to the researchers behind a new study published to the journal Evolutionary Anthropology.
And, it’s a trend that still dominates our culture today.
‘It’s a need that we’ve been perennially faced with and driven by,’ says lead author Justin Pargeter, an anthropologist at Emory University. ‘Miniaturization is the thing that we do.’
According to Pargeter, evidence of tiny stone tools can be found throughout the archaeological record. Many of these tools measure less than an inch in length.
In the first miniaturization spike, human ancestors two million years ago used stone flakes to cut, slice, and pierce – tasks they previously relied on their teeth or fingernails for.
In a second surge after 100,000 years ago, the development of the bow and arrow and other forms of high-speed weaponry necessitated light-weight stone components.
And, toward the end of the last Ice Age 17,000 years ago, humans were forced to adapt to a changing climate and had to conserve their resources, including rocks used to make tools.
‘When other apes used stone tools, they chose to go big and stayed in the forests where they evolved,’ says co-author John Shea, professor of anthropology at Stony Brook University.
‘Hominins chose to go small, went everywhere, and transformed otherwise hostile habitats to suit our changing needs.’
The iconic, tear-drop shaped hand axe (left) required a large toolkit to produce (left), in contrast to a toolkit for tiny flakes. Examples of miniaturized stone tools (right) have appeared over the last 2.6 million years, showing mastery of aerodynamics
Until Pargeter rediscovered the tiny quartz tool, it sat in storage at the Iziko Museum in Cape Town after it was collected with other artifacts from Boomplaas
‘It was diminutive, about the size of a small raisin, and weighed less than half a penny,’ Pargeter said.
‘You could literally blow it off your finger.’
‘It suddenly occurred to me that archaeologists may have missed a major component of our stone tool record,’ Pargeter says.
‘In our desire to make “big” discoveries we may have overlooked tiny, but important, details.
‘A whole technology could lay hidden behind our methods, relegated to bags considered waste material.’
Miniaturization is ‘a need that we’ve been perennially faced with and driven by,’ says lead author Justin Pargeter, an anthropologist at Emory University. ‘Miniaturization is the thing that we do’
WHEN DID HUMANS START USING TOOLS?
It is hard for scientists to say precisely when humans started making tools because the more primitive remains look like a natural object rather than a human artefact.
The oldest-known instruments are the Oldowan stone tools from Ethiopia, which date back about 2.6 million years.
The Acheulean tool technology period – up to 1.76 million years ago – featured large stone hand axes made from flint and quartzite.
Towards the end of this period, the tools became more refined and then followed the so-called Levallois technique, which saw the creation of scrapers, slicers, needled and flattened needles.
About 50,000 years ago more refined and specialised flint tools were made and used by Neanderthals and it is believed it was at this stage tools were constructed out of bone.
As human culture advanced, artefacts such as fish hooks, buttons and bone needles were used.
Cut marks have found on animal bones that have been dated to be 3.4 million years old – around the time that a squat ape-like ancestor called Australopithecus afarensis – known as Lucy – roamed Africa.
According to the researcher, this type of arrow-tip could have been affixed to an arrow shaft using a plant-based resin.
And, laced with poison from a plant or insect, it could take down prey without wasting much material.
‘The link shaft goes into the animal, sacrificing the small blade, but the arrow shaft pops out so you can retain this more costly component,’ Pargeter says.
‘Our ancestors were masters of aerodynamics and acted like engineers, rather than what we think of as “cave people.”
The crystal quartz flake found at Boomplaas Cave in South Africa was previously dismissed as waste
‘They built redundancy into their technological systems, allowing them to easily repair their tools and to reduce the impact of errors.’
This type of small-scale tool making is vastly different than other forms of tool use among primates.
‘The hands of other primates are not evolved for repeated fine manipulation in high-force tasks,’ Pargeter says.
‘We’re evolved a unique precision grip that ratchets up our ability for miniaturized technology.’
‘Smaller tools are the choice of technology for a mobile, dispersing population,’ Pargeter says.
‘When Homo sapiens left Africa they weren’t carrying bulky hand axes, but bows and arrows and smaller stone implements.’
WHAT DO WE KNOW ABOUT THE HISTORY OF THE STONE AGE?
The stone age is a period in human prehistory distinguished by the original development of stone tools that covers more than 95 per cent of human technological prehistory.
It begins with the earliest known use of stone tools by hominins, ancient ancestors to humans, during the Old Stone Age – beginning around 3.3 million years ago.
Between roughly 400,000 and 200,000 years ago, the pace of innovation in stone technology began to accelerate very slightly, a period known as the Middle Stone Age.
By the beginning of this time, handaxes were made with exquisite craftsmanship. This eventually gave way to smaller, more diverse toolkits, with an emphasis on flake tools rather than larger core tools.
The stone age is a period in human prehistory distinguished by the original development of stone tools that covers more than 95 per cent of human technological prehistory. This image shows neolithic jadeitite axes from the Museum of Toulouse
These toolkits were established by at least 285,000 years in some parts of Africa, and by 250,000 to 200,000 years in Europe and parts of western Asia. These toolkits last until at least 50,000 to 28,000 years ago.
During the Later Stone Age the pace of innovations rose and the level of craftsmanship increased.
Groups of Homo sapiens experimented with diverse raw materials, including bone, ivory, and antler, as well as stone.
The period, between 50,000 and 39,000 years ago, is also associated with the advent of modern human behaviour in Africa.
Different groups sought their own distinct cultural identity and adopted their own ways of making things.
Later Stone Age peoples and their technologies spread out of Africa over the next several thousand years.