A Stone Age boat building site has been discovered underwater

A Stone Age boat building site has been discovered underwater

This is an oblique view of site from the north showing eroding edge of the peat platform. Credit: Maritime Archaeological Trust

The Maritime Archaeological Trust has discovered a new 8,000 year old structure next to what is believed to be the oldest boat building site in the world on the Isle of Wight.

Director of the Maritime Archaeological Trust, Garry Momber, said "This new discovery is particularly important as the wooden platform is part of a site that doubles the amount of worked wood found in the UK from a period that lasted 5,500 years."

The site lies east of Yarmouth, and the new platform is the most intact, wooden Middle Stone Age structure ever found in the UK. The site is now 11 meters below sea level and during the period there was human activity on the site, it was dry land with lush vegetation. Importantly, it was at a time before the North Sea was fully formed and the Isle of Wight was still connected to mainland Europe.

The site was first discovered in 2005 and contains an arrangement of trimmed timbers that could be platforms, walkways or collapsed structures. However, these were difficult to interpret until the Maritime Archaeological Trust used state of the art photogrammetry techniques to record the remains. During the late spring the new structure was spotted eroding from within the drowned forest. The first task was to create a 3D digital model of the landscape so it could be experienced by non-divers. It was then excavated by the Maritime Archaeological Trust during the summer and has revealed a cohesive platform consisting of split timbers, several layers thick, resting on horizontally laid round-wood foundations.

Garry continued "The site contains a wealth of evidence for technological skills that were not thought to have been developed for a further couple of thousand years, such as advanced wood working. This site shows the value of marine archaeology for understanding the development of civilisation.

Yet, being underwater, there are no regulations that can protect it. Therefore, it is down to our charity, with the help of our donors, to save it before it is lost forever."

The Maritime Archaeological Trust is working with the National Oceanography Centre (NOC) to record and study, reconstruct and display the collection of timbers. Many of the wooden artefacts are being stored in the British Ocean Sediment Core Research facility (BOSCORF), operated by the National Oceanography Centre.

Stone Age boat
This is the structure following reconstruction. Credit: Maritime Archaeological Trust

As with sediment cores, ancient wood will degrade more quickly if it is not kept in a dark, wet and cold setting. While being kept cold, dark and wet, the aim is to remove salt from within wood cells of the timber, allowing it to be analysed and recorded. This is important because archaeological information, such as cut marks or engravings, are most often found on the surface of the wood and are lost quickly when timber degrades. Once the timbers have been recorded and have desalinated, the wood can be conserved for display.

Dr Suzanne Maclachlan, the curator at BOSCORF, said "It has been really exciting for us to assist the Trust's work with such unique and historically important artefacts. This is a great example of how the BOSCORF repository is able to support the delivery of a wide range of marine science."

When diving on the submerged landscape Dan Snow, the history broadcaster and host of History Hit, one of the world's biggest history podcasts, commented that he was both awestruck by the incredible remains and shocked by the rate of erosion.

This material, coupled with advanced wood working skills and finely crafted tools suggests a European, Neolithic (New Stone Age) influence. The problem is that it is all being lost. As the Solent evolves, sections of the ancient land surface are being eroded by up to half a metre per year and the archaeological evidence is disappearing.

Research in 2019 was funded by the Scorpion Trust, the Butley Research Group, the Edward Fort Foundation and the Maritime Archaeology Trust. Work was conducted with the help of volunteers and many individuals who gave their time and often money, to ensure the material was recovered successfully.

Stone Age boat
This is historian Dan Snow inspecting the site. Credit: Maritime Archaeological Trust

Press release from National Oceanography Centre


East Africa

Ancient DNA tells the story of the first herders and farmers in east Africa

Ancient DNA tells the story of the first herders and farmers in east Africa

A collaborative study that includes a SLU-Madrid archaeologist provides new insights on early human interaction

East Africa
Herders move goats through the Engaruka Basin in northern Tanzania's Rift Valley. Ancient DNA shows that this way of life spread to East Africa through multiple population movements. Credit: Katherine Grillo

ST. LOUIS, MO (May 30, 2019) - A collaborative study led by archaeologists, geneticists and museum curators is providing answers to previously unsolved questions about life in sub-Saharan Africa thousands of years ago. The results were published online in the journal Science Thursday, May 30.

Researchers from North American, European and African institutions analyzed ancient DNA from 41 human skeletons curated in the National Museums of Kenya and Tanzania, and the Livingstone Museum in Zambia.

"The origins of food producers in East Africa have remained elusive because of gaps in the archaeological record," said co-first author Mary Prendergast, Ph.D., professor of anthropology and chair of humanities at Saint Louis University's campus in Madrid, Spain.

"This study uses DNA to answer previously unresolvable questions about how people were moving and interacting," added Prendergast.

The research provides a look at the origins and movements of early African food producers.

The first form of food production to spread through most of Africa was the herding of cattle, sheep and goats. This way of life continues to support millions of people living on the arid grasslands that cover much of sub-Saharan Africa.

"Today, East Africa is one of the most genetically, linguistically, and culturally diverse places in the world," explains Elizabeth Sawchuk, Ph.D., a bioarchaeologist at Stony Brook University and co-first author of the study. "Our findings trace the roots of this mosaic back several millennia. Distinct peoples have coexisted in the Rift Valley for a very long time."

Previous archaeological research shows that the Great Rift Valley of Kenya and Tanzania was a key site for the transition from foraging to herding. Herders of livestock first appeared in northern Kenya around 5000 years ago, associated with elaborate monumental cemeteries, and then spread south into the Rift Valley, where Pastoral Neolithic cultures developed.

The new genetic results reveal that this spread of herding into Kenya and Tanzania involved groups with ancestry derived from northeast Africa, who appeared in East Africa and mixed with local foragers there between about 4500-3500 years ago. Previously, the origins and timing of these population shifts were unclear, and some archaeologists hypothesized that domestic animals spread through exchange networks, rather than by movement of people.

After around 3500 years ago, herders and foragers became genetically isolated in East Africa, even though they continued to live side by side. Archaeologists have hypothesized substantial interaction among foraging and herding groups, but the new results reveal that there were strong and persistent social barriers that lasted long after the initial encounters.

Another major genetic shift occurred during the Iron Age around 1200 years ago, with movement into the region of additional peoples from both northeastern and western Africa. These groups contributed to ancient ancestry profiles similar to those of many East Africans today. This genetic shift parallels two major cultural changes: farming and iron-working.

The study provided insight into the history of East Africa as an independent center of evolution of lactase persistence, which enables people to digest milk into adulthood. This genetic adaptation is found in high proportions among Kenyan and Tanzanian herders today.

Co-first author Mary Prendergast, Ph.D., is a professor of anthropology and chair of humanities at Saint Louis University's campus in Madrid, Spain. Credit: Mary Prendergast

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Traces of crawling in Italian cave give clues to ancient humans' social behavior

Traces of crawling in Italian cave give clues to ancient humans' social behavior

Using multiple methods of analysis, researchers have identified the movements of a group of humans as they explored an Italian cave system during the late Stone Age

The video shows a virtual exploration of the Bàsura cave, with a reconstruction of the group of ancient humans that proceeded via the 'Corridoio delle Impronte' to reach the inner rooms. Credit: MUSE - Isabella Salvador and Filippo Menolli

cave of Bàsura Toirano Liguria
In the cave of Bàsura, a preliminary survey of fossil traces is carried out on glossy sheets as a reference for more detailed analyses. Credit: Isabella Salvador

Evidence of crawling in an Italian cave system sheds new light on how late Stone Age humans behaved as a group, especially when exploring new grounds, says a study published today in eLife.

The cave of Bàsura at Toirano and its human and animal fossil traces have been known since the 1950s, with the first studies conducted by Italian archaeologist Virginia Chiappella. In the current study, promoted by the Archaeological Heritage Office of Liguria, researchers from Italy, Argentina and South Africa used multiple approaches to analyse the human traces and identified for the first time crawling behaviours from around 14,000 years ago.

"In our study, we wanted to see how ancient humans explored this fascinating cave system," says first author Marco Romano, Postdoctoral Fellow at the University of the Witwatersrand, South Africa. "Specifically, we set out to discover how many people entered the cave, whether they explored as individuals or as a group, their age, gender and what kind of route they took once inside the cave."

To answer these questions, the multidisciplinary team studied 180 tracks from within the cave, including foot and handprints on the clay-rich floor. They applied various modern dating methods, software that analyses the structure of the tracks, and different types of 3D modelling. "Together, these approaches allowed us to construct a narrative of how the humans entered and exited the cave, and their activities once they were inside," Romano explains.

The team determined that five individuals, including two adults, an adolescent of about 11 years old, and two children of three and six years old, entered the cave barefoot and illuminated the way using wooden sticks. This suggests that young children were active group members during the late Stone Age, even when carrying out apparently dangerous activities.

The researchers reported the first evidence of crawling in footprints from a low tunnel - a route that was taken to access the inner part of the cave. Anatomical details in the footprints suggest that the explorers went bare-legged as they navigated this pathway.

When analysing the various handprints, the team found that some of them appear 'unintentional' and relate to exploring the cave only, while others are more 'intentional' and suggest that social or symbolic activities took place within the inner chambers. "Hunter-gatherers may therefore have been driven by fun activities during exploration, as well as simply the need to find food," Romano adds.

"Together, our results show how a varied approach to studying our ancestors' tracks can provide detailed insights on their behaviour," concludes senior author Marco Avanzini, head of the geology department at MUSE - Trento Museum of Science, Italy. "We hope our approach will be useful for painting similar pictures of how humans behaved in other parts of the world and during different periods of time."

cave of Bàsura Toirano Liguria
These are ancient human footprints impressed on different surfaces in the cave of Bàsura. Credit: Marco Avanzini

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Reference

The paper 'A multidisciplinary approach to a unique Palaeolithic human ichnological record from Italy (Bàsura Cave)' can be freely accessed online at https://doi.org/10.7554/eLife.45204.

Press release from eLife


Megalith tombs were family graves in European Stone Age

Megalith tombs were family graves in European Stone Age

In a new study published in the Proceedings of the National Academy of Sciences, an international research team, led from Uppsala University, discovered kin relationships among Stone Age individuals buried in megalithic tombs on Ireland and in Sweden. The kin relations can be traced for more than ten generations and suggests that megaliths were graves for kindred groups in Stone Age northwestern Europe.

Agriculture spread with migrants from the Fertile Crescent into Europe around 9,000 BCE, reaching northwestern Europe by 4,000 BCE. Starting around 4,500 BCE, a new phenomenon of constructing megalithic monuments, particularly for funerary practices, emerged along the Atlantic façade. These constructions have been enigmatic to the scientific community, and the origin and social structure of the groups that erected them has remained largely unknown. The international team sequenced and analysed the genomes from the human remains of 24 individuals from five megalithic burial sites, encompassing the widespread tradition of megalithic construction in northern and western Europe.

The team collected human remains of 24 individuals from megaliths on Ireland, in Scotland and the Baltic island of Gotland, Sweden. The remains were radiocarbon-dated to between 3,800 and 2,600 BCE. DNA was extracted from bones and teeth for genome sequencing. The team compared the genomic data to the genetic variation of Stone Age groups and individuals from other parts of Europe. The individuals in the megaliths were closely related to Neolithic farmers in northern and western Europe, and also to some groups in Iberia, but less related to farmer groups in central Europe.

Paternal continuity through time

The team found an overrepresentation of males compared to females in the megalith tombs on the British Isles. Credit: Göran Burenhult

The team found an overrepresentation of males compared to females in the megalith tombs on the British Isles.

"We found paternal continuity through time, including the same Y-chromosome haplotypes reoccurring over and over again," says archaeogeneticist Helena Malmström of Uppsala University and co-first author. "However, female kindred members were not excluded from the megalith burials as three of the six kinship relationships in these megaliths involved females."

A likely parent-offspring relation was discovered for individuals in the Listhogil Tomb at the Carrowmore site and Tomb 1 at Primrose Grange, about 2 km distance away from each other. Credit: Göran Burenhult

The genetic data show close kin relationships among the individuals buried within the megaliths. A likely parent-offspring relation was discovered for individuals in the Listhogil Tomb at the Carrowmore site and Tomb 1 at Primrose Grange, about 2 km distance away from each other. "This came as a surprise. It appears as these Neolithic societies were tightly knit with very close kin relations across burial sites," says population-geneticist Federico Sanchez-Quinto of Uppsala University and co-first author.

The Ansarve tomb was used by distinct groups

Megalith tombs Ansarve site Listhogil site Primrose Grange Carrowmore site archaeogenetics
The Ansarve site on the island of Gotland in the Baltic Sea is embedded in an area with mostly hunter-gathers at the time. Credit: Magdalena Fraser

The Ansarve site on the island of Gotland in the Baltic Sea is embedded in an area with mostly hunter-gathers at the time. "The people buried in the Ansarve tomb are remarkably different on a genetic level compared to the contemporaneous individuals excavated from hunter-gather-contexts, showing that the burial tradition in this megalithic tomb, which lasted for over 700 years, was performed by distinct groups with roots in the European Neolithic expansion," says archaeogeneticist Magdalena Fraser of Uppsala University and co-first author.

"That we find distinct paternal lineages among the people in the megaliths, an overrepresentation of males in some tombs, and the clear kindred relationships point to towards the individuals being part of a patrilineal segment of the society rather than representing a random sample from a larger Neolithic farmer community," says Mattias Jakobsson, population-geneticist at Uppsala University and senior author of the study.

"Our study demonstrates the potential in archaeogenetics to not only reveal large-scale migrations, but also inform about Stone Age societies and the role of particular phenomena in those times such as the megalith phenomena," says Federico Sanchez-Quinto.

"The patterns that we observe could be unique to the Primrose, Carrowmore, and Ansarve burials, and future studies of other megaliths are needed to tell whether this is a general pattern for megalith burials," says osteoarchaeologist Jan Storå of Stockholm University.

 

 

Publication

Sánchez-Quinto et al. (2019) Megalithic tombs in western and northern Neolithic Europe were linked to a kindred society, PNAS, DOI: 10.1073/pnas.1818037116 (Open access)
www.pnas.org/cgi/doi/10.1073/pnas.1818037116

Facts

This study is part of the Atlas project, a multidisciplinary effort to understand Eurasian and Scandinavian prehistory, funded by Riksbankens Jubileumsfond and the Knut and Alice Wallenberg foundation.

Press release from Uppsala University, by Linda Koffmar.


barley Sweden Finland agriculture farming hunter gatherers Pitted Ware Culture

A 5,000-year-old barley grain discovered in Finland changes understanding of livelihoods

A 5,000-year-old barley grain discovered in Finland changes understanding of livelihoods

barley Sweden Finland agriculture farming hunter gatherers Pitted Ware Culture
Researchers determined the age of millennia-old barley grains using radiocarbon dating. Credit: photo by Santeri Vanhanen, CC-BY 4.0 licence

New findings reveal that hunter-gatherers took to farming already 5,000 years ago in eastern Sweden, and on the Aland Islands, located on the southwest coast of Finland

On the basis of prior research, representatives of the Pitted Ware Culture from the Stone Age have been known as hard-core sealers, or even Inuits of the Baltic Sea. Now, researchers have discovered barley and wheat grains in areas previously inhabited by this culture, leading to the conclusion that the Pitted Ware Culture adopted agriculture on a small scale.

A study carried out in cooperation with parties representing the discipline of archaeology and the Department of Chemistry at the University of Helsinki, as well as Swedish operators in the field of archaeology (The Archaeologists, a governmental consultant agency, and Arkeologikonsult, a business), found grains of barley and wheat in Pitted Ware settlements on Finland's Aland Islands and in the region of modern Stockholm.

The age of the grains was ascertained using radiocarbon dating. Based on the results, the grains originated in the period of the Pitted Ware culture, thus being approximately 4,300-5,300 years old. In addition to the cereal grains, the plant remnants found in the sites included hazelnut shells, apple seeds, tuberous roots of lesser celandine and rose hips.

The study suggests that small-scale farming was adopted by the Pitted Ware Culture by learning the trade from farmers of the Funnel Beaker Culture, the latter having expanded from continental Europe to Scandinavia.

Other archaeological artefacts are also evidence of close contact between these two cultures.

"The grains found on Aland are proof that the Pitted Ware Culture introduced cultivation to places where it had not yet been practised," says Santeri Vanhanen, a doctoral student of archaeology at the University of Helsinki.

In the study, the age of cereal grains found at the sites tagged with numbers in the map were determined with radiocarbon dating. These findings demonstrate that hunter-gatherers adopted farming on the Åland Islands on the southwestern coast of Finland and in eastern Sweden already 5,000 years ago. Credit: Santeri Vanhanen, CC-BY 4.0 licence

Cereal perhaps used to brew beer?

The 5,000-year-old barley grain found on Aland is the oldest grain of cereal ever found in Finland. The researchers also found a handful of barley and wheat grains a few hundred years younger, representing either common wheat or club wheat.

"We also dated one barley grain found in Raseborg, southern Finland. This grain and the other earliest grains found in mainland Finland date back some 3,500 years, some 1,500 years behind Aland according to current knowledge," Vanhanen explains.

In prior studies, it has been extremely difficult to demonstrate that the hunter-gatherer population would have adopted farming during recorded history, let alone in the Stone Age. Research on ancient DNA has in recent years proven that the spread of agriculture in Europe was almost exclusively down to migrants.

"We find it possible that this population, which was primarily specialised in marine hunting, continued to grow plants as the practice provided the community with social significance."

From time to time, an abundance of pig bones are found at Pitted Ware sites, even though pigs were not an important part of their daily nourishment. For instance, the bones of more than 30 pigs were found in a grave located on the island of Gotland.

"Members of the Pitted Ware culture may have held ritual feasts where pigs and cereal products were consumed. It's not inconceivable that grains might even have been used to brew beer, but the evidence is yet to be found," Vanhanen continues.

Santeri Vanhanen is a doctoral student of archaeology at the University of Helsinki. Credit: Marko Marila

Grain age determined through radiocarbon dating

The research relies primarily on archaeobotanical methodology, which helps examine plant remains preserved in archaeological sites. In this study, soil samples were collected from the sites, from which plant remains were extracted using a flotation method. The plant remains are charred; in other words, the grains and seeds have turned into carbon after having come to contact with fire.

Plant remains can be identified by examining them through a microscope and comparing them to modern plant parts. The age of individual grains can be determined with radiocarbon dating, based on the fractionation of the radioactive carbon-14 isotope. This way, the age of a grain aged several millennia can be determined with a precision of a few centuries.

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The study was published in the Scientific Reports journal on 20 March 2019. The research article, entitled "Maritime Hunter-Gatherers Adopt Cultivation at the Farming Extreme of Northern Europe 5000 Years Ago", is freely available on the journal's website: https://www.nature.com/articles/s41598-019-41293-z

This is how the Inuit culture of the Baltic Sea was born. Read more on the University of Helsinki website: https://www.helsinki.fi/en/news/language-culture/a-5000-year-old-barley-grain-discovered-in-aland-southern-finland-turns-researchers-understanding-of-ancient-northern-livelihoods-upside-down

Press release from the University of Helsinki


From Stone Age chips to microchips: How tiny tools may have made us human

From Stone Age chips to microchips: How tiny tools may have made us human

The technology of miniaturization set hominins apart from other primates

The iconic, tear-drop shaped hand axe, which filled a human palm, required a large toolkit to produce (left), in contrast to a toolkit for tiny flakes. Credit: Emory University

Anthropologists have long made the case that tool-making is one of the key behaviors that separated our human ancestors from other primates. A new paper, however, argues that it was not tool-making that set hominins apart -- it was the miniaturization of tools.

Just as tiny transistors transformed telecommunications a few decades ago, and scientists are now challenged to make them even smaller, our Stone Age ancestors felt the urge to make tiny tools. "It's a need that we've been perennially faced with and driven by," says Justin Pargeter, an anthropologist at Emory University and lead author of the paper. "Miniaturization is the thing that we do."

Stone Age miniaturization stone tools prehistory
Going small may have helped some humans survive the last period of rapid climate change, 17,000 years ago, says Emory anthropologist Justin Pargeter. Credit: Emory University

The journal Evolutionary Anthropology is publishing the paper -- the first comprehensive overview of prehistoric tool miniaturization. It proposes that miniaturization is a central tendency in hominin technologies going back at least 2.6 million years.

"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 paper reviews how stone flakes less than an inch in length -- used for piercing, cutting and scraping -- pop up in the archeological record at sites on every continent, going back to some of the earliest known stone tool assemblages. These small stone flakes, Pargeter says, were like the disposable razor blades or paperclips of today -- pervasive, easy to make and easily replaced.

He identifies three inflection points for miniaturization in hominin evolution. The first spike occurred around two million years ago, driven by our ancestors' increasing dependence on stone flakes in place of nails and teeth for cutting, slicing and piercing tasks. A second spike occurred sometime after 100,000 years ago with the development of high-speed weaponry, such as the bow and arrow, which required light-weight stone inserts. A third spike in miniaturization occurred about 17,000 years ago. The last Ice Age was ending, forcing some humans to adapt to rapid climate change, rising sea levels and increased population densities. These changes increased the need to conserve resources, including the rocks and minerals needed to make tools.

A native of South Africa, Pargeter co-directs field work in that country along its rugged and remote Indian Ocean coastline and nearby inland mountains. He is also a post-doctoral fellow in Emory University's Center for Mind, Brain and Culture and the Department of Anthropology's Paleolithic Technology Laboratory. The lab members actually make stone tools to better understand how our ancestors learned these skills, and how that process shaped our evolution. The lab's director, Dietrich Stout, focuses on hand axes, dating back more than 500,000 years. These larger tools are considered a turning point in human biological and cognitive evolution, due to the complexity involved in making them.

Pargeter's work on tiny tools adds another facet to the investigation of human evolution. "He's exploring what may have led to the compulsion to produce these tiny instruments -- essentially the relationship between the tools and the human body, brain and the probable uses of the tools," Stout says.

When looking for a PhD thesis topic, Pargeter first focused on collections of larger implements, considered typical of the Stone Age tool kit. He pored over artifacts from a South African site called Boomplaas that were being held in storage at the Iziko Museum in Cape Town. As he rummaged through a bag labelled as waste -- containing small flakes thought to be left over from making larger tools -- something caught his eye. A sliver of crystal quartz looked like it had been shaped using a highly technical method called pressure flaking.

"It was diminutive, about the size of a small raisin, and weighed less than half a penny," he recalls. "You could literally blow it off your finger."

Pargeter examined the flake under a magnifying glass. He noticed it had a distinctive, stair-step fracture on its tip that previous experimental research showed to be associated with damage caused in hunting.

"It suddenly occurred to me that archeologists 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."

So how to interpret the use of a tool so tiny that you could easily blow it off your finger?

Pargeter began thinking of this question in terms of the age of the flake -- about 17,000 years -- and the environment at the time. The last Ice Age was ending and massive melting of ice at the poles caused the global sea-level to rise. In parts of South Africa, the rising oceans swallowed an area the size of Ireland. As the coastal marshes and grasslands disappeared -- along with much of the game and aquatic life -- the hunter-gatherers living there fled inland to sites like Boomplaas, currently located about 80 kilometers inland. The mountains around Boomplaas provided permanent springs and other dependable freshwater sources.

The climate, however, was less predictable, with sudden shifts in temperature and rainfall. Vegetation was shifting dramatically, temperatures were rising and large mammals were increasingly scarce. Archaeology from Boomplaas shows that people ate small game like hares and tortoises. These small animals would have been easy to catch, but they provided limited nutritional packages.

"These are low-reward food sources, indicating a foraging stress signal," Pargeter says. "Boomplaas might have even served as a type of refugee camp, with groups of hunter-gatherers moving away from the coast, trying to survive in marginal environments as resources rapidly depleted and climate change ratcheted up."

Arrow points a little less than an inch across were already in the archaeological literature, but the Boomplaas crystal quartz flake was half that size. In order to bring down an animal, Pargeter hypothesized, the Boomplaas flake would need poison on its tip -- derived either from plants or insects -- and a high-speed delivery system, such as a bow and arrow.

The tiny crystal flake, from a site in South Africa called Boomplaas, that sparked Justin Pargeter to investigate Stone Age miniaturization. Credit: Justin Pargeter

Pargeter used his own extensive knowledge of prehistoric tool-making and archaeology to hypothesize that the tiny flake could have been hafted, using a plant-based resin, onto a link shaft, also likely made of a plant-based material, such as a reed. That link shaft, about the length of a finger, would in turn fit onto a light arrow shaft.

"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," he says. "Our ancestors were masters of aerodynamics and acted like engineers, rather than what we think of as 'cave people.' They built redundancy into their technological systems, allowing them to easily repair their tools and to reduce the impact of errors."

Our ancestors were also connoisseurs of the type of fine-grained rocks needed for tool-making.

Supplies of such vital toolmaking raw materials, however, were likely diminished as the rising oceans consumed land and people became more crowded together, driving them to more carefully conserve what they could find on the landscape.

As paleoanthropologists are faced with more than three million years of hominin "stuff," one of the perennial questions they keep seeking to answer is, what makes us humans unique? "We've typically said that tool use makes us human, but that's kind of buckled under," Pargeter says, as evidence of tool use by other animals accumulates.

Macaques, for example, use rocks to smash apart oysters. Chimpanzees use rocks as hammers and anvils to crack nuts and they modify sticks to dig and fish for termites. These tools, however, are large. "The hands of other primates are not evolved for repeated fine manipulation in high-force tasks," Pargeter says. "We've evolved a unique precision grip that ratchets up our ability for miniaturized technology."

Humans are also the masters of dispersing into novel environments, unlike other primates that remained in the landscapes of their ancestors. "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."

 

Press release from Emory Health Sciences