New Ideas About the Old Stone Age
and Human Evolution
Drs Sonia Harmand & Jason Lewis
Rewrite The Story of Human Evolution
Rewrite The Story of Human Evolution
Overturning widely held beliefs with new evidence
Preconceptions often stand in the way of new discoveries. This article discusses the problems with widely held assumptions and then provides examples of assumptions that were recently overturned and which have now led to a possible new understanding of human evolution. Drs Sonia Harmand & Jason Lewis found stone tools much older than the generally accepted earliest Oldowan tools in a wooded terrain rather than the generally accepted savanna environment. They also hypothesized that the tools were made by an earlier hominid, Australopithecus, who had not been considered a likely candidate for stone tool making. And finally, they proposed a new understanding relating to the evolution of the human brain. Instead of assuming that it was a larger brain that kick-started human tool making, it may, instead, have been the prefrontal cortex.
When the paintings in the Cave of Altamira in Spain were made public, experts assumed that primitive man was not capable of such skills and therefore rejected their authenticity.
Men who have excessive faith in their theories or ideas are not only ill-prepared for making discoveries; they also make very poor observations. Of necessity, they observe with a preconceived idea, and when they devise an experiment, they can see, in its results, only a confirmation of their theory. In this way, they distort observations and often neglect very important facts because they do not further their aim.As I have written before, assumptions often stand in the way of scientific facts. Often these ideas are hidden or embedded in a way of thinking. And because of that, they are hard to identify.
Bernard, Claude. An Introduction to the Study of Experimental Medicine (1865). New York: Dover Publications, Inc., 1957.
EXAMPLES OF ASSUMPTIONS
When I have read about the earliest known (that is the earliest until now) stone tools, the Oldowan tools, I have consistently come across descriptions of the technology as simple or crude
-- "The extreme crudeness of most Oldowan choppers"[1]
-- Oldowan were "crude stone tools, essentially broken river cobbles"[1]
-- "Oldowan industry, toolmaking tradition characterized by crudely worked pebble (chopping) tools"
-- "The tools...are chipped in two directions to form simple, rough, all-purpose tools."[2]
-- "The more primitive tools, typically chunks of stone with crudely-chipped edges, belong to the earlier Oldowan toolkit."[3]
But Alison Brooks, Professor of Anthropology, Center for the Advanced Study of Human Paleobiology, George Washington University and Research Associate, Human Origins Program, Smithsonian Institution said this about Harmand's work:
"It...confirms an assertion we made in a 2002 paper ["Older than the Oldowan," Panger et al. Evolutionary Anthropology] that the oldest Oldowan artifacts at 2.5+0.15 Ma were too sophisticated to represent the dawn of human technology.[4]
An Oldowan chopper.
In this example, Oldowan tools might look simple and crude to our modern eyes, but from an evolutionary standpoint, they were a remarkable achievement which had taken perhaps a million years to achieve. So I believe it is a mistake to characterize Oldowan tools as simple & crude when speaking about them in a paleoanthropological sense.
"Giambattista Vico [ED: a philosopher of history] believed that every theory must start from the point where the subject of which it treats began to take shape."[5]These tools needed to be looked at from the point of view of an early hominid, millions of years ago, learning to understand the properties of stone and different types of stone with a specific purpose in mind, such as creating a sharp cutting edge. And when looked at this way, the achievement was quite significant.
About AssumptionsMany if not most assumptions are valid. However, it is important to be aware of those assumptions and to probe them when new facts or data bring them into question.Now to be fair -- there are many new and unusual ideas that will not past muster. Each needs to be looked at carefully. As Carl Sagan said about scientific ideas, "Extraordinary claims require extraordinary evidence." Or as Pierre-Simon Laplace said in the 1700s, "The weight of evidence for an extraordinary claim must be proportioned to its strangeness." Yet each work needs to be judged on its merits but not because it is different or because something like it has never been seen before.
THE NEW STORY OF HUMAN EVOLUTION
Dr. Sonia Harmand and her research team have questioned many current assumptions and as a result, have made a breakthrough.
"Our finding disproves the long-standing assumption that Homo habilis [ED: who made Oldowan tools] was the first tool maker."[4]
"Conventional wisdom in human evolutionary studies...has supposed that the origins of knapping stone tools was linked to the emergence of the genus Homo, and this technological development was tied to climate change and the spread of savannah grasslands," says Dr. Lewis, co-director of the fieldwork.[4]
Read their full article online:
An Earlier Origin For Stone Tool Making:
Implications For Cognitive Evolution And The Transition To Homo
Implications For Cognitive Evolution And The Transition To Homo
OR
Download the PDF version. {13]
Dr. Harmand's team has proposed a new paradigm involving the timeline and development of stone tool making. Their ideas go to the heart of human evolution and the creatures who were part of that evolution -- ideas which are very different from the paleoanthropological model that has been in place for the last 80 years.
The ideas, like many great ideas, are quite simple and profound. It seems that these ideas came about because the team asked some basic questions and/or was open to discoveries in places and in time periods that were outside the normally accepted zones of paleoanthropology.
When Dr. Harmand realized that some stone tools had been found that were older than the earliest homo fossils, e.g. Homo habilis, she began to wonder if the tools might have been made by an earlier species. And although most of the previous finds and excavations were located in the savannas, she also thought there could have been some earlier human-like development in wooded areas that were apart from the savannas.
Both of these ideas have turned out to be true. She found a full set of stone tools that had been crafted by hominids before the genus Homo, presumably Australopithecines, in a wooded environment in Kenya. And these tools were 700,000 years older than the oldest Oldowan tools -- which paleoanthropologists had assumed were the oldest such tools.
She called the newly discovered tool technology Lomekwian after the location where the tools were found, Lomekwi. While some people have suggested the tools should be called pre-Oldowan because they were tools that preceded the better crafted later Oldowan stone tools, Dr. Harmand maintains that the Lomekwian method for knapping the stones was so different that it needed its own unique name.
And there was another aspect to this remarkable discovery. These simpler and more basic Lomekwian stone tools, which nevertheless had been carefully made, fit nicely into a continuum of stone tool use from the ape world to the genus homo world.
And again, this was another conventional assumption.
The seemingly punctuated appearance of rather well-controlled stone knapping capabilities in the early Oldowan leads to it being characterized as a ‘cognitive leap’ or ‘something from nothing’ [ED: as stated by paleolithic technology experts]. [4]But Dr. Harmand showed that this technology did not come out of nowhere although this had been the opinion that had prevailed for almost a century.
Some primates use stones to break open nuts.
Chimpanzees, for example, use stones to break open nuts. Most of their stone tool use involves percussive actions such as smashing a nut with a large stone. Knapping, or deliberately striking one stone with another stone to create sharp flakes or to shape a core stone, is only a human activity. And while quite basic, that is what the Lomekwian stone tools showed with a variety of artifacts including flakes, cores, hammers, and anvils.
"Lomekwian tools were made by bashing two rocks together to create flakes with sharp edges -- which primates do not do." Yet “the material from 3.3 million years ago [ED: Lomekwian] looks a lot more like the materials that we see even made by modern primates,” said archaeologist David Braun of George Washington University. [7]
"Stone tool making might no longer be considered characteristic only of Homo. It could now also be attributed to earlier hominins like Australopithecus...having developed from pre-existing stone manipulation and tool-use behaviours of our primate ancestors," wrote Dr. Sonia Harmand. [4]
THE TOOL MAKING PROCESS
A general illustration of stone tool making steps, but not intended to illustrate Lomekwian tools.
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FROM THE ARTICLE BY DRS HARMAND AND LEWIS
The development of any technical system involves an increasing number of steps. Each step consists of a chain of actions, underpinned by decision-making; the second step is a consequence of the first and allows the third and so on, until the anticipated goal is achieved. The success of hominin stone knapping specifically requires:
[ED: These steps would have required a rudimentary sense of linear time such as "before" and "after" because this process or any process with steps requires this.]
(1) an understanding of the fracture mechanics of the available stone raw materials, and most preferable sizes and shapes of the initial blocks for knapping;
(2) sensorimotor control over the force and accuracy involved in the percussive gestures required to strike off flakes from the stone block, and;
(3) a visuo-spatial understanding of the locations and angles at which to strike the core and detach flakes such that each removal doesn't alter the core's morphology in such a way that further detachments are not possible (core maintenance). [6]
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THE IMPORTANCE OF PROCESSES
Over the years, I have written detailed articles about processes that are similar to the above description.
The Importance of Processes in the Paleolithic Era
"It seems plausible that the ability to create stone tools requires some additional cognitive abilities: not just recognizing what would be a useful tool, but also creating it," said Alexandra Rosati at Harvard University in Cambridge, Massachusetts. [8]
"The study of the Lomekwian artifacts suggest they could represent a transitional technological stage -- a missing link -- between the pounding-oriented stone tool use of a more ancestral hominin and the flaking-oriented knapping of later, Oldowan toolmakers." [4]But even after establishing and proving these claims, there was still one more assumption that needed to be dealt with. That assumption was that brain size was the critical factor when it came to intelligence.
"A paleoanthropologist who studies the evolution of human cognition at the University of Colorado, Colorado Springs, ...[said]. “There’s nothing about the stone tools that requires big brains,” he said. “And it’s big brains that are really the major defining characteristic of the genus homo.” ([He] argues that humans subsequently made superior tools because their brains were better able to process how to hit a stone to give it the desired shape.)"[9]
An artist's imaginative concept of Australopithecines.
But now there was another possibility. Other parts of the brain, such as the prefrontal cortex, might have become more developed even though the brain size remained about the same.
DEFINITION
The prefrontal cortex functions in cognitive control (e.g. planning, attention, problem-solving, error-monitoring, decision-making, social cognition, and working memory).
Definition: Prefrontal cortex, Nature, https://www.nature.com/subjects/prefrontal-cortex [10]
"Perhaps the most extreme example of short-term memory [ED: which involves the prefrontal cortex] is a chess master who can explore several possible solutions mentally before choosing the one that will lead to checkmate." [11]
SHORT-TERM MEMORY': McGill University, Montreal, Canada
http://thebrain.mcgill.ca/flash/d/d_07/d_07_cr/d_07_cr_tra/d_07_cr_tra.html
And this is where my work comes in. In 2014 I wrote an article in which I explained that a sense of linear time (i.e., just like a sense of smell or taste) was unique to humans and that this sense came in part from the prefrontal cortex which was more developed in humans than in any other species. Since I wrote that article, it has been read by about 8,000 people and is my most popular post. In it I attempted to prove that a concept of linear time -- which included past, present, future, and duration -- was central and critical to our human ability to control and master the world around us.
Animal Senses Compared to the Human Sense of Time
So I find it fascinating that Dr. Harmand and her team decided the prefrontal cortex was a key factor in the earliest stone tools made by bipedal Australopithecines even though their brains were no larger than that of a chimpanzee. Admittedly this is speculation but it does merit exploration into another widely held assumption.
Dr. Harmand wrote, "The origins of stone knapping [ED: breaking a stone with another stone using deliberate controlled force] may have been associated with increased development of prefrontal, motor and parietal cortex asymmetries, and their consequent cognitive and physical capabilities, but not with the drastic increases in absolute and relative brain size seen after 2 ma with the genus homo."[6]
These ideas were given support in a separate study entitled, "Interpreting sulci on hominin endocasts." Author, Dr. Dean Falk, wrote, "Compared to great apes, Australopithecus endocasts reproduce a clear middle frontal sulcus in the dorsolateral prefrontal cortex that is derived toward the human condition.... The comparative and direct evidence ...suggests that hominin brain reorganization was underway by at least the time of Australopithecus africanus (~2.5 to 3.0 mya), despite the ape-sized brains of these hominins."[12]From my perspective, i.e., the human experience of time, this puts the human sense of time at the forefront of human evolution. It seems that we may have begun to perceive linear time right from the start as this sense may have been there long before our brains grew to the enormous size that they are today. So it appears possible that a sense of time was fundamental, perhaps even leading the way from the very beginning, for us to evolve.
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FOOTNOTES
"Experiments by anthropologists show that fossil footprints made 3.6 million years ago are the earliest direct evidence of early hominids using the kind of efficient, upright posture and gait now seen in modern humans." [14]
2. "Oldowan industry." Britannica. Britannica.com.
<https://www.britannica.com/topic/Oldowan-industry> Accessed 5/11/2020.
3. Kaplan, Matt. "Stone tools shed light on early human migrations." Nature: International weekly journal of science. Nature.com. <https://www.nature.com/news/2011/110831/full/news.2011.511.html> Accessed 5/11/2020.
4. Stony Brook University. "Archaeologists find earliest evidence of stone tool making." ScienceDaily. ScienceDaily, 20 May 2015. <www.sciencedaily.com/releases/2015/05/150520131659.htm> Accessed 5/11/2020.
5. Whitrow, Gerald James. Time in History: Views of Time from Prehistory to the Present Day. Oxford, UK, Oxford University Press. 1988, page 150.
6. Lewis, Jason E, and Sonia Harmand. “An earlier origin for stone tool making: implications for cognitive evolution and the transition to Homo.” Philosophical transactions of the Royal Society of London. Series B, Biological sciences vol. 371,1698 (2016): 20150233. doi:10.1098/rstb.2015.0233
<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4920290/> Accessed 5/11/2020.
7. Lewis, Dyani. "For those about to rock: the birthplace of humanity’s tool kit found." Cosmos Magazine, June 2019. Cosmosmagazine.com. <https://cosmosmagazine.com/archaeology/for-those-about-to-rock-the-birthplace-of-humanity-s-tool-kit-found> Accessed 5/11/2020.
8. Barras, Colin. "Chimpanzees and monkeys have entered the Stone Age." BBC, August 2015. BBC.com. <http://www.bbc.com/earth/story/20150818-chimps-living-in-the-stone-age> Accessed 5/11/2020.
9. Zorich, Zach. "Which Came First, Humans or Tools?" The New Yorker, May 2015. Newyorker.com. <https://www.newyorker.com/tech/annals-of-technology/which-came-first-humans-or-tools> Accessed 5/11/2020.
10. Definition: "Prefrontal cortex." Nature. Nature.com. <https://www.nature.com/subjects/prefrontal-cortex>
11. "SHORT-TERM MEMORY." McGill University, Montreal, Canada.
Mcgill.ca.
<http://thebrain.mcgill.ca/flash/d/d_07/d_07_cr/d_07_cr_tra/d_07_cr_tra.html> Accessed 5/11/2020.
12. Falk, Dean. “Interpreting sulci on hominin endocasts: old hypotheses and new findings.” Frontiers in human neuroscience vol. 8 134. 1 May. 2014, DOI:10.3389/fnhum.2014.00134
<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4013485/> Accessed 5/11/2020.
TO DOWNLOAD THE PDF FILE:
13. Harmand, Sonia; Lewis, Jason." 3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya." Nature, May 15, 2015. doi:10.1038/nature14464.
<https://geology.rutgers.edu/images/Publications_PDFS/Harmand_et_al_2015_short.pdf> Accessed 5/11/2020.
14. University of Arizona. "Evidence indicates humans' early tree-dwelling ancestors were also bipedal." ScienceDaily. ScienceDaily, 20 March 2010. <www.sciencedaily.com/releases/2010/03/100319202526.htm>. Accessed 5/11/2020.
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