Did Neanderthals Make Glue?

didneanderthalsmakeglue

BY FAZALE RANA – JANUARY 10, 2018

Fun fact: each year, people around the world purchase 50 billion dollars’ (US) worth of adhesives. But perhaps this statistic isn’t all that surprising—because almost everything we make includes some type of bonding agent.

In the context of human prehistory, anthropologists consider adhesives to have been a transformative technology. They would have provided the first humans the means to construct new types of complex devices and combine different types of materials (composites) into new technologies.

Anthropologists also consider the production and use of adhesives to be a diagnostic of advanced cognitive capabilities, such as forward planning, abstraction, and understanding of materials. Production of adhesives from natural sources, even by the earliest modern humans, appears to have been a complex operation, requiring precise temperature control and the use of earthen mounds, or ceramic or metal kilns. The first large-scale production of adhesives usually centered around the dry distillation of birch and pine barks to produce tar and pitch.

Even though modern humans perfected dry distillation methods for tar production, the archaeological record seemingly indicates that it wasn’t modern humans who first manufactured adhesives from tar, but, instead, Neanderthals. The oldest evidence for tar production and use dates to around 200,000 years ago, based on organic residues recovered from a site in Italy. It appears that Neanderthals were using the tar as glue for hafting flint spearheads to wooden spear shafts.1 Archaeologists have also unearthed spearheads with tar residue from two sites in Germany dating to 120,000 years in age and between 40,000 to 80,000 years in age, respectively.2 Because these dates precede the arrival of modern humans into Europe, anthropologists assume the tar at these sites was deliberately produced and used by Neanderthals.

For some anthropologists, this evidence indicates that Neanderthals possessed advanced cognitive ability, just like modern humans. If this is the case, then modern humans are not unique and exceptional. And, if human beings aren’t exceptional, then it becomes a challenge to defend one of the central concepts in Scripture—the idea that human beings are made in God’s image. Yet, claims that Neanderthals are cognitive equals to modern humans fail to withstand scientific scrutiny, time and time again. (See Resources section below.) This, too, is the case when it comes to Neanderthal tar production.

How Did Neanderthals Extract Tar from Birch Bark?

Though it appears that Neanderthals were able to produce and use tar as an adhesive, anthropologists have no idea how they went about this task. Archaeologists have yet to unearth any evidence for ceramics at Neanderthal sites. To address this question, a team of researchers from the University of Leiden conducted a series of experiments, trying to learn how Neanderthals could dry distill tar from birch bark using the resources most reasonably available to them.

The research team devised and evaluated three dry distillation methods:

  • The Ash Mound Method: This technique entails burying rolled up birch bark in hot ash and embers. The heat from the ash and embers distills the tar away from the birch bark, but because the bark is curled and buried, oxygen can’t easily get to the tar, preventing combustion.
  • The Pit Roll Method: This approach involves digging a cylindrical pit and then placing a burning piece of rolled-up birch bark in the pit, followed by covering it with earthen materials.
  • The Raised Structure Method: This method involves placing a vessel made out of birch bark in a pit, igniting it, and covering it with sticks, pebbles, and mud.

Of the three methods, the researchers learned that the Pit Roll technique produced the most tar and was the most efficient method. Still, the amount of tar that was produced was not enough for large-scale use, but just enough to haft one or two spears at best. The tar produced by all three methods was too fluid to be used for hafting.

Still, the research team concluded that Neanderthals could have dry distilled tar from birch bark, using methods that were simple and without the need to precisely control the distillation temperature. They also conclude that Neanderthals must have had advanced cognitive abilities—on par with modern humans—to pull off this feat.

Did Neanderthals Have Similar Cognitive Capacity to Modern Humans?

Does the ability of Neanderthals to dry distill tar (using crude methods) and use it to haft spears reflect sophisticated cognitive abilities? From my vantage point, no.

The recognition that the methods Neanderthals most likely used to dry distill tar from birch bark didn’t require temperature control and were simple and crude argues againstNeanderthal sophistication, not for it. To this point, it is worth noting that birch bark naturally curls, a factor critical to the success of the three dry distillation methods explored by the University of Leiden archaeologists. In other words, curling the birch bark was not something Neanderthals would have had to discover.

It is also worth pointing out that recent work indicates that Neanderthals did not master fire, but instead made opportunistic use of fire. These creatures could not create fire, but, instead, harvested wildfires. There were vast periods of time during Neanderthals’ tenure in Europe when wildfires were rare because of cold climatic conditions, meaning Neanderthals didn’t have access to fire. Because fire is central to the dry distillation methods, Neanderthals would have been unable to extract tar and use it for hafting for a significant portion of their time on Earth. Perhaps this explains why recovery of tar from Neanderthal sites is a rare occurrence.

Still, no matter how crude the method, dry distilling tar from birch bark seems to be pretty remarkable behavior—until we compare Neanderthal behavior to that of chimpanzees.

Comparing Neanderthal Behavior to Chimpanzee Behavior

In recent years, primatologists have observed chimpanzees in the wild engaging in some remarkable behaviors. For example, chimpanzees:

  • manufacture spears from tree branches, using a six-step process. In turn, these creatures use these spears to hunt bush babies
  • make stone tools that they use to break open nuts
  • collect branches from specific trees with appropriate mechanical characteristics and insect-repellent properties to build beds in trees
  • collect and consume plants with medicinal properties
  • understand and exploit the behavior of wildfires

In light of these remarkable chimpanzee behaviors, the manufacture and use of tar by Neanderthals doesn’t seem that impressive. No one would equate a chimpanzee’s cognitive capacity with that of a modern human. And, likewise, no one should equate the cognitive capacity of Neanderthals with modern humans. In terms of sophistication, complexity, and efficiency, the tar production methods of modern humans are categorically different from those of Neanderthals, reflecting cognitive superiority of modern humans.

Do Anthropologists Display a Bias against Modern Humans?

Recently, in a New York Times article, science writer Jon Mooallem called attention to paleoanthropologists’ prejudices when it comes to Neanderthals. He pointed out that the limited data available to these scientists from the archaeological record forces them to rely on speculation. And this speculation is inevitably influenced by their preconceptions. Mooallem states,

“All sciences operate by trying to fit new data into existing theories. And this particular science [archaeology], for which the “data” has always consisted of scant and somewhat inscrutable bits of rock and fossil, often has to lean on those metanarratives even more heavily. . . . Ultimately, a bottomless relativism can creep in: tenuous interpretations held up by webs of other interpretations, each strung from still more interpretations. Almost every archaeologist I interviewed complained that the field has become “overinterpreted”—that the ratio of physical evidence to speculation about that evidence is out of whack. Good stories can generate their own momentum.”3

Mooallem’s critique applies to paleoanthropologists who are “modern human supremacists”and those with an “anti-modern human bias” that seeks to undermine the uniqueness and exceptionalism of modern humans. And, lately, reading the scientific literature in anthropology, I get the strong sense that there is a growing anti-modern human bias among anthropologists.

In light of this anti-modern human bias, one could propose an alternate scenario for the association of tar with flint spearheads at a few Neanderthal sites that comport with the view that these creatures were cognitively inferior to modern humans. Perhaps Neanderthals threw birch or pine into a fire they harvested from a wildfire. And maybe a few pieces of bark or some pieces of branches near the edge of the fire naturally curled, leading to “dry distillation” of small amounts of tar. Seeing the tar exude from the bark, perhaps a Neanderthal poked at it with his spear, coating the piece of flint with sticky tar.

When we do our best to set aside our preconceptions, the collective body of evidence indicates that Neanderthals did not have the same cognitive capacity as modern humans.

Resources

Endnotes

  1. Paul Peter Anthony Mazza et al., “A New Palaeolithic Discovery: Tar-Hafted Stone Tool in a European Mid-Pleistocene Bone-Bearing Bed,” Journal of Archaeological Science 33 (September 2006): 1310–18, doi:10.1016/j.jas.2006.01.006.
  2. Johann Koller, Ursula Baumer, and Dietrich Mania, “High-Tech in the Middle Palaeolithic: Neandertal-Manufactured Pitch Identified,” European Journal of Archaeology 4 (December 1, 2001): 385–97, doi:10.1179/eja.2001.4.3.385; Alfred F. Pawlik and Jürgen P. Thissen, “Hafted Armatures and Multi-Component Tool Design at the Micoquian Site of Inden-Altdorf, Germany,” Journal of Archaeological Science38 (July 2011): 1699–1708, doi:10.1016/j.jas.2011.03.001.
  3. P. R. B. Kozowyk et al., “Experimental Methods for the Palaeolithic Dry Distillation of Birch Bark: Implications for the Origin and Development of Neandertal Adhesive Technology,” Scientific Reports 7 (August 31, 2017): 8033, doi:10.1038/s41598-017-08106-7.
  4. Jon Mooallem, “Neanderthals Were People, Too,” New York Times Magazine, January 11, 2017, https://www.nytimes.com/2017/01/11/magazine/neanderthals-were-people-too.html.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/01/10/did-neanderthals-make-glue

New Research Douses Claim that Neanderthals Mastered Fire

newresearchdousesclaim

BY FAZALE RANA – JANUARY 3, 2018

A few months ago, I posted a link on Twitter to a blog article I wrote challenging the claim that Neanderthals made jewelry and, therefore, possessed the capacity for symbolism.

When I post articles about the cognitive abilities of Neanderthals, I expect them to generate a fair bit of discussion and opinions that differ from mine (and I expect this article about neanderthal’s use of fire to be no exception). But one response I received was unexpectedly jarring. It came from a Christian who accused me of being “out of touch,” “wasting time discussing frivolous issues,” and “targeting the elite with a failed apologetic.” He admonished me to spend my time on real issues related to social justice concerns and chastised me for not focusing my efforts reaching out to the “marginalized.”

As part of my reply to my new “friend,” I pointed out that the identity and capability of Neanderthals has a direct bearing on the gospel and, consequently, social injustices in our world, because it relates to the question of humanity’s origin and identity. And what we believe about where we come from really matters.

Scripture teaches that human beings are uniquely made in God’s image. And, it is the image of God that renders human beings of infinite worth and value. Because we bear God’s image, Christ died to reconcile us to the Father. And, as Christians, the immeasurable value we place on all human life motivates us to battle against the injustices of the world—because the people who suffer these injustices are image bearers. According to Scripture, when we love and serve other human beings, it equates to loving and serving God.

Yet, the biblical view of humanity has been supplanted in the scientific community by human evolution. According to this idea, human beings are not the product of a Creator’s handiwork—the crown of creation—but, like all life on Earth, we emerged through unguided, historically contingent processes. In the evolutionary paradigm, human beings hold no special status. Human beings possess no inherent worth. We possess no more value than any other creature that has ever existed throughout Earth’s history. Human beings lack any inherent worth or dignity in the evolutionary paradigm. And, within this framework, there can be no ultimate meaning or purpose to human life.

Sadly, the evolutionary view of humanity is not confined to the halls of the academy. It permeates and influences cultures throughout the world. Once human life is rendered meaningless and stripped of its inherent value, there is no fundamental justification to stand against injustice. In fact, it becomes easier to excuse acts of injustice and becomes tolerable to look the other way when these acts occur. In the evolutionary framework, no genuine motivation exists to rescue the marginalized of our world. I would go one step further and argue that many of the social ills we face throughout the world have their etiology in the evolutionary view of humanity.

I regard my work as a Christian apologist as an antidote to this toxic worldview. Towards this end, I strive to demonstrate the credibility of the biblical view of humanity—apart from biblical and theological appeals. In an increasingly secular world, we can’t simply adopt a theological stance, declaring that human beings bear God’s image, and leave it at that. Few nonbelievers will accept that approach. We must respond to the scientific challenge to the image of God with scientific evidence for human uniqueness and exceptionalism. This endeavor isn’t about challenging the elite with an obscure apologetic argument for the validity of Christianity. Ultimately, it is about establishing the foundation for the gospel and generating the impetus and justification to treat human beings as creatures with inherent worth and dignity. As Christian apologists when we “target the elite” with apologetic arguments for the Christian worldview, we are serving the marginalized in our world.

As described in Who Was Adam? a scientific case can be marshaled for human exceptionalism in a way that aligns with the biblical view of the image of God. Remarkably, a growing minority of anthropologists and primatologists now believe that human beings really are exceptional. They contend that human beings do, indeed, differ in kind, not just degree, from other creatures. The scientists who argue for this updated perspective have developed evidence for human exceptionalism within the context of the evolutionary paradigm in their attempts to understand how the human mind evolved. Yet, ironically, these new insights marshal support for the biblical conception of humanity.

However, one potential challenge to human exceptionalism relates to the cognitive capabilities of Neanderthals. Based on archeological and fossil finds some paleoanthropologists now argue that these hominids: (1) buried their dead; (2) made specialized tools; (3) used ochre; (4) produced jewelry; (5) created art; and (6) even had language capacities. These are behaviors one would naturally associate with the image bearers.

Yet, as discussed in Who Was Adam? (and articles listed in the Resource section), careful examination of the archeological and fossil evidence reveals just how speculative the claims about Neanderthal “exceptionalism” are. Recent insights on Neanderthal fire use illustrate this point.

Did Neanderthals Use Fire?

While controversy abounds among paleoanthropologists about fire use by hominins such as Homo erectus, most scientists working in this field believe Neanderthals mastered fire. This view finds its basis in the discovery of primitive hearths, burned bones, heated lithics, and charcoal at Neanderthal archeological sites. Frankly, fire use by Neanderthals bothers me. If these creatures could create and use fire—in short, if they mastered fire (called pyrotechnology)—it makes them much more like us—but uncomfortably so.

Yet, recent work raises questions about Neanderthal fire usage.1 Careful assessment of archeological sites in southern France occupied by Neanderthals from about 100,000 to 40,000 years ago indicates that Neanderthals could not create fire. Instead, they made opportunistic use of natural fire when available to them.

The French sites show clear evidence of fire use by Neanderthals. However, when researchers correlated the archeological layers harboring evidence for fire use with paleoclimate data, they found an unexpected pattern. Neanderthals used fire during warm climate conditions and failed to use fire during cold periods—the opposite of what would be predicted—if Neanderthals had mastery over fire.

Instead, this unusual correlation indicates that Neanderthals made opportunistic use of fire. Lightning strikes that would generate natural fires are much more likely to occur during warm periods. Instead of creating fire, Neanderthals most likely collected natural fire and cultivated it as long as they could before it extinguished.

Such evidence shows that human beings are unique and exceptional in our capacity to create and curate fire, distinguishing us from Neanderthals.

Chimpanzees Exploit Natural Fire

Still, the capacity to make opportunistic use of fire seems pretty impressive. At least until Neanderthal behavior is compared to that of chimpanzees. Recent work by Jill Pruetz indicates that these great apes understand the behavior of natural fires and even exploit them.2 Pruetz and her collaborator observed the response of the Fongoli community of chimpanzees to two wildfires in the spring of 2006. The members of the community calmly monitored the fires at close range and then changed their behavior in anticipation of the fires’ movement. To put it another way, the chimpanzees’ behavior was predictive, not responsive. This capacity is impressive, because the behavior of natural fires is complex, depending on wind speed and direction and the amount and type of fuel sources.

So, as impressive as Neanderthal behavior may seem, their opportunistic use of fire seems more closely in line with chimpanzee behavior than that of human beings, who create and control fire at will. In fact, Pruetz believes one reason chimpanzees don’t harvest natural fire relates to their lack of manual dexterity.

How Did Neanderthals Survive Cold Climates without Fire?

If Neanderthals were opportunistic exploiters of fire and it was only available to them when the climate was warm, how did they survive the cold? One possibility is that they simply migrated from cold climes to warmer ones.

Another possibility is that the hominins made clothing. At least, this is the common narrative about Neanderthals. Yet, recent work indicates that this popular depiction is incorrect. These creatures did not make clothing from animal skins, but instead made use of animal hides as capes.3

A team of paleoanthropologists reached this conclusion by studying the faunal remains at Neanderthal and modern human archeological sites and comparing them to a database of animals used to make cold weather clothing. While both modern humans and Neanderthals used deer, bison, and bear hides for body coverings, the remains of these creatures were found more frequently at modern human archeological sites. Additionally, the remains of smaller creatures, such as weasels, wolverines, and dogs were found at modern human sites but were absent from sites occupied by Neanderthals. These smaller animals have no food value. Instead, modern humans used the animal hides to trim clothing.

This data indicates that modern humans made much more frequent use of animal hides for clothing than did Neanderthals. And when modern humans made clothing, it was more elaborate and well-fitted than the coverings made by Neanderthals. This conclusion finds added support from the discovery of bone needles at modern human archeological sites (and the absence of these artifacts at Neanderthal sites), and reflects cognitive differences between human beings and Neanderthals.

Even though Neanderthals made poorly crafted body coverings and most likely made little use of fire during cold periods, they were aided in their survival of frigid conditions by the design of their bodies. Anthropologists describe Neanderthals as having a hyper-polar body design that made them well-adapted to live under frozen conditions. Neanderthal bodies were stout and compact, comprised of barrel-shaped torsos and shorter limbs, which helped them retain body heat. Their noses were long and sinus cavities extensive, which helped them warm the cold air they breathed before it reached their lungs. Neanderthals most likely survived the cold because of their body design, not because of their cognitive abilities.

Even though many paleoanthropologists assert that Neanderthals possessed cognitive abilities on par with modern humans, careful evaluation finds these claims wanting, time and time again, as the latest insights about fire use by these hominins attest.

Compared to the hominins, including Neanderthals, human beings do, indeed, appear to be exceptional in a way that aligns with the image of God. These are far from “frivolous issues.” The implications are profound.

What we think about Neanderthals really matters.

Resources

Endnotes

  1. Dennis M. Sandgathe et al., “Timing of the Appearance of Habitual Fire Use,” Proceedings of the National Academy of Sciences, USA 108 (July 19, 2011), E298, doi:10.1073/pnas.1106759108Paul Goldberg et al., “New Evidence on Neandertal Use of Fire: Examples from Roc de Marsal and Pech de l’Azé IV,” Quaternary International 247 (2012), 325–40, doi:10.1016/j.quaint.2010.11.015; Dennis M. Sandgathe et al., “On the Role of Fire in Neanderthal Adaptations in Western Europe: Evidence from Pech de l’Azé IV and Roc de Marsal, France,” PaleoAnthropology (2011), 216–42, doi:10.4207/PA.2011.ART54.
  2. Jill D. Pruetz and Thomas C. LaDuke, “Brief Communication: Reaction to Fire by Savanna Chimpanzees (Pan troglodytes verus) at Fongoli, Senegal: Conceptualization of “Fire Behavior” and the Case for a Chimpanzee Model,” American Journal of Physical Anthropology 141 (April 2010) 646–50, doi:10.1002/ajpa.21245.
  3. Mark Collard et al., “Faunal Evidence for a Difference in Clothing Use between Neanderthals and Early Modern Humans in Europe,” Journal of Anthropological Archaeology 44 B (December 2016), 235–46, doi:org/10.1016/j.jaa.2016.07.010.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/01/03/new-research-douses-claim-that-neanderthals-mastered-fire

Were Neanderthals People, Too? A Response to Jon Mooallem

neanderthalspeopletoo

BY FAZALE RANA – FEBRUARY 8, 2017

Recently, I conducted an informal survey through my Facebook page, asking my friends, “What do you think is the most significant scientific challenge to the Christian faith?”

The most consistent concern related to Neanderthals. Why did God create these creatures (and other hominids)? How do we make sense of human-Neanderthal interbreeding? What about Neanderthal behavior? Didn’t these creatures behave just like us?

These questions are understandable. And they are reinforced by popular science articles such as the piece by Jon Mooallem published recently (January 11, 2017) in the New York Times Magazine. In this piece, Mooallem interviews paleoanthropologist Clive Finlayson about his research at Gorham’s Cave (Gibraltar)—work that Finlayson claims provides evidence that Neanderthals possessed advanced cognitive abilities, just like modern humans—just like us.1

Finlayson’s team discovered hatch marks made in the bedrock of Gorham’s Cave. They age-date the markings to be more than 39,000 years old. The layer immediately above the bedrock dated between 30,000 and 38,000 years old and contained Neanderthal-produced artifacts, leading the team to conclude that these hominids made the markings, and the hatch marks represent some form of proto-art.2

In his piece, Mooallem cites other recent scientific claims that support Finlayson’s interpretation of Neanderthal behavioral capacity. Based on archaeological and fossil finds, some paleoanthropologists argue that these hominids: (1) buried their dead, (2) made specialized tools, (3) used ochre, (4) produced jewelry, and (5) even had language capacities.

This view of Neanderthals stands as a direct challenge to the view espoused by the RTB human origins model, specifically the notion of human exceptionalism and the biblical view that humans alone bear the image of God.

Mooallem argues that paleoanthropologists have been slow to acknowledge the sophisticated behavior of Neanderthals because of a bias that reflects the earliest views about these creatures—a view that regards these hominids as “unintelligent brutes.” Accordingly, this view has colored the way paleoanthropologists interpret archaeological finds associated with Neanderthals, keeping them from seeing the obvious: Neanderthals had sophisticated cognitive abilities. In fact, Mooallem accuses paleoanthropologists who continue to reject this new view of Neanderthals as being “modern human supremacists,” guilty of speciesism, born out of an “anti-Neanderthal prejudice.”

Mooallem offers a reason why this prejudice continues to persist among some paleoanthropologists. In part, it’s because of the limited data available to them from the archaeological record. In the absence of a robust data set, paleoanthropologists must rely on speculation fueled by preconceptions. Mooallem states,“

All sciences operate by trying to fit new data into existing theories. And this particular science, for which the ‘data’ has always consisted of scant and somewhat inscrutable bits of rock and fossil, often has to lean on those meta-narratives even more heavily. . . . Ultimately, a bottomless relativism can creep in: tenuous interpretations held up by webs of other interpretations, each strung from still more interpretations. Almost every archaeologist I interviewed complained that the field has become ‘overinterpreted’—that the ratio of physical evidence to speculation about that evidence is out of whack. Good stories can generate their own momentum.”3

Yet, as discussed in my book Who Was Adam? (and articles listed below in the Resources section), careful examination of the archaeological and fossil evidence reveals just how speculative the claims about Neanderthal “exceptionalism” are. Could it be that the claims of Neanderthal art and religion result from an overinterpreted archaeological record, and not the other way around?

In effect, Mooallem’s critique of the “modern human supremacists” cuts both ways. In light of the limited and incomplete data from the archaeological record, it could be inferred that paleoanthropologists who claim Neanderthals have sophisticated cognitive capacities, just like modern humans, have their own prejudices fueled by an “anti-modern human bias” and a speciesism all their own—a bias that seeks to undermine the uniqueness and exceptionalism of modern humans. And to do this they must make Neanderthals out to be just like us.

As to the question: Why did God create these creatures (and the other hominids)? That will have to wait for another post. So stay tuned…

Resources

Endnotes

  1. Jon Mooallem, “Neanderthals Were People, Too,” New York Times Magazine, January 11, 2017, https://www.nytimes.com/2017/01/11/magazine/neanderthals-were-people-too.html.
  2. Joaquín Rodríguez-Vidal et al., “A Rock Engraving Made by Neanderthals in Gibraltar,” Proceedings of the National Academy of Sciences, USA 111 (September 2014): 13301–6, doi:10.1073/pnas.1411529111.
  3. Mooallem, “Neanderthals Were People.”
Reprinted with permission by the author
Original article at:
https://reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2017/02/08/were-neanderthals-people-too-a-response-to-jon-mooallem

Blood Flow to Brain Contributes to Human Exceptionalism

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BY FAZALE RANA – SEPTEMBER 21, 2016

Are human beings exceptional? Are we unique, as the Bible teaches?

Recent work by paleoanthropologists from Australia adds to the mounting scientific evidence for human exceptionalism. These scientists demonstrate that modern humans have an unusually high rate of blood flow to our brains, compared to other primates, including the hominids represented in the fossil record.1 They argue that the increased blood flow to the human brain reflects an unusually high level of: (1) neuron-neuron connectivity; and (2) synaptic activity. Ultimately, these enhanced capabilities support the uniquely advanced cognitive capacity displayed by modern humans. To put it differently, the increased blood flow to the modern human brain helps account for the cognitive differences between humans and the other hominids, including Neanderthals.

This research helps support a key prediction of RTB’s human origins model (derived from the biblical text) by demonstrating a fundamental difference between humans and Neanderthals.

Measuring Blood Flow to Hominid Brains

To establish the relative blood flow to the brains of modern humans and hominids, the researchers measured the radius of the opening of two holes at the base of the skull that serve as the entryway for the internal carotid arteries. These blood vessels accommodate about 85 percent of the blood flow to the human brain. These arteries also give rise to the middle cerebral arteries (which supply the lateral portions of the frontal, parietal, and temporal lobes) and the anterior cerebral arteries (which supply the medial parts of the frontal, and parietal lobes).

 

blood-flow-to-brain-contributes-to-human-exceptionalism-1

Image: Internal Carotid Artery. Credit: Wikipedia

These holes in the skull exclusively provide the conduits for the internal carotid arteries. No accompanying nerves or veins pass through these openings. Blood flow and blood pressure controls the radius and the wall thickness of the arteries, making the size of these openings a reasonable proxy for blood flow to the brain.

Performing measurements only for complete and undamaged skull openings, the researchers determined the radius of the carotid openings for 34 hominid specimens, representing 12 species, including:

  • africanus (8 specimens)
  • afarensis (3 specimens)
  • boisei (1 specimen)
  • habilis (1 specimen)
  • naledi (1 specimen)
  • rudolfensis (1 specimen)
  • georgicus (1 specimen)
  • erectus (5 specimens)
  • heidelbergensis (2 specimens)
  • neanderthalensis (5 specimens)
  • floresiensis (1 specimen)
  • Archaic sapiens (5 specimens)

Brain Blood Flow in Hominids

In lower primates, neuron numbers increase with brain mass in a linear manner (because neurons occupy a constant volume). Measurements made in a previous study for 34 haplorhine primates saw brain blood flow scaling with brain volume.

But the researchers observed something different for the hominids. While the blood flow to the brain scaled with increases in brain volume for the Australopithecines and early Homospecies, a different pattern was observed for H. erectusH. heidelbergensis, and Neanderthals. Increases in cerebral blood grew at a faster pace than expected based on increases in brain size.

For modern humans, the increase in cerebral blood flow maxes out, even departing further from the trend line observed for the late appearing Homo species. To put it another way, modern humans (H. sapiens sapiens) stand as an outlier, with an unusually high cerebral blood flow, even compared to Neanderthals.

Differences in Brain Blood Flow between Humans and Neanderthals

The primate brain possesses an extremely high aerobic demand, requiring prodigious amounts of oxygen. For modern humans, the brain is responsible for 25 percent of our resting metabolic activity. The brain needs a constant supply of oxygen and nutrients (such as glucose). The disproportionate blood flow to the human brain reflects the high level of interneuronal activity and synaptic transmissions between nerve cells.

Even though Neanderthals had roughly the same brain size as modern humans, the cerebral blood flow to their brain was significantly lower. This observation implies that these hominids inherently lacked the capacity to support the same high level of interneuronal connectivity and synaptic activity as modern humans. This result lines up with a wide range of other findings (detailed in the expanded and updated edition of Who Was Adam?) indicating Neanderthals had limited cognitive capacity compared to modern humans. Collectively, these results justify skepticism regarding claims that these creatures possessed symbolic capability (language, art, music, body ornamentation, etc.).

Brain Blood Flow and Implications for Human Uniqueness

This research helps support a key prediction of RTB’s human origins model (derived from the biblical text) by demonstrating a fundamental difference between humans and Neanderthals. Instead of viewing hominids as evolutionary transitional forms, RTB’s biblical model holds that hominids, including Neanderthals, were animals made by God. They possessed intelligence and emotional capacity, but lacked the image of God—a quality associated only with anatomically modern humans (Genesis 1:26–27). Therefore, we expect that Neanderthals would have displayed behavior that is qualitatively different from, and inferior to, that of modern humans. This study provides confirmation of this expectation.

This study also provides scientific support for the biblical teaching that human beings are uniquely made in God’s image. If human beings truly are image bearers, then we should expect that scientific data would emerge for human exceptionalism, and it has in a way that aligns with the biblical perspective of humanity’s unique cognitive and behavioral capacities.

Resources
Who Was Adam?: A Creation Model Approach to the Origin of Humanity by Fazale Rana with Hugh Ross (book)
Neanderthal Brains Make Them Unlikely Social Networkers” by Fazale Rana (article)
Did Neanderthals Make Art?” by Fazale Rana (article)
Did Neanderthals Bury Their Dead with Flowers?” by Fazale Rana (article)
Do Neanderthal Cave Structures Challenge Human Exceptionalism?” by Fazale Rana (article)
Human, Neanderthal Brains Only Differ after Birth” by Fazale Rana (podcast)

Endnotes

  1. Roger Seymour, Vanya Bosiocic, and Edward Snelling, “Fossil Skulls Reveal that Blood Flow Rate to the Brain Increased Faster than Brain Volume during Human Evolution,” Royal Society Open Science 3 (August 2016): 160305, doi:10.1089/rsos.160305.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2016/09/21/blood-flow-to-brain-contributes-to-human-exceptionalism