Differences in Human and Neanderthal Brains Explain Human Exceptionalism

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BY FAZALE RANA – SEPTEMBER 19, 2018

When I was a little kid, my mom went through an Agatha Christie phase. She was a huge fan of the murder mystery writer and she read all of Christie’s books.

Agatha Christie was caught up in a real-life mystery of her own when she disappeared for 10 days in December 1926 under highly suspicious circumstances. Her car was found near her home, close to the edge of a cliff. But, she was nowhere to be found. It looked as if she disappeared without a trace, without any explanation. Eleven days after her disappearance, she turned up in a hotel room registered under an alias.

Christie never offered an explanation for her disappearance. To this day, it remains an enduring mystery. Some think it was a callous publicity stunt. Some say she suffered a nervous breakdown. Others think she suffered from amnesia. Some people suggest more sinister reasons. Perhaps, she was suicidal. Or maybe she was trying to frame her husband and his mistress for her murder.

Perhaps we will never know.

Like Christie’s fictional detectives Hercule Poirot and Miss Marple, paleoanthropologists are every bit as eager to solve a mysterious disappearance of their own. They want to know why Neanderthals vanished from the face of the earth. And what role did human beings (Homo sapiens) play in the Neanderthal disappearance, if any? Did we kill off these creatures? Did we outcompete them or did Neanderthals just die off on their own?

Anthropologists have proposed various scenarios to account for the Neanderthals’ disappearance. Some paleoanthropologists think that differences in the cognitive capabilities of modern humans and Neanderthals help explain the creatures’ extinction. According to this model, superior reasoning abilities allowed humans to thrive while Neanderthals faced inevitable extinction. As a consequence, we replaced Neanderthals in the Middle East, Europe, and Asia when we first migrated to these parts of the world.

Computational Neuroanatomy

Innovative work by researchers from Japan offers support for this scenario.1 Using a technique called computational neuroanatomy, researchers reconstructed the brain shape of Neanderthals and modern humans from the fossil record. In their study, the researchers used four Neanderthal specimens:

  • Amud 1 (50,000 to 70,000 years in age)
  • La Chapelle-aux Saints 1 (47,000 to 56,000 years in age)
  • La Ferrassie 1 (43,000 to 45,000 years in age)
  • Forbes’ Quarry 1 (no age dates)

They also worked with four Homo sapiens specimens:

  • Qafzeh 9 (90,000 to 120,000 years in age)
  • Skhūl 5 (100,000 to 135,000 years in age
  • Mladeč 1 (35,000 years in age)
  • Cro-Magnon 1 (32,000 years in age)

Researchers used computed tomography scans to construct virtual endocasts (cranial cavity casts) of the fossil brains. After generating endocasts, the team determined the 3D brain structure of the fossil specimens by deforming the 3D structure of the average human brain so that it fit into the fossil crania and conformed to the endocasts.

This technique appears to be valid, based on control studies carried out on chimpanzee and bonobo brains. Using computational neuroanatomy, researchers can deform a chimpanzee brain to accurately yield the bonobo brain, and vice versa.

Brain Differences, Cognitive Differences

The Japanese team learned that the chief difference between human and Neanderthal brains is the size and shape of the cerebellum. The cerebellar hemisphere is projected more toward the interior in the human brain than in the Neanderthal brain and the volume of the human cerebellum is larger. Researchers also noticed that the right side of the Neanderthal cerebellum is significantly smaller than the left side—a phenomenon called volumetric laterality. This discrepancy doesn’t exist in the human brain. Finally, the Japanese researchers observed that the parietal regions in the human brain were larger than those regions in Neanderthals’ brains.

differences-in-human-and-neanderthal-brains
Image credit: Shutterstock

 

Because of these brain differences, the researchers argue that humans were socially and cognitively more sophisticated than Neanderthals. Neuroscientists have discovered that the cerebellum helps motor functions and higher cognition by contributing to language function, working memory, thought, and social abilities. Hence, the researchers argue that the reduced size of the right cerebellar hemisphere in Neanderthals limits the connection to the prefrontal regions—a connection critical for language processing. Neuroscientists have also discovered that the parietal lobe plays a role in visuo-spatial imagery, episodic memory, self-related mental representations, coordination between self and external spaces, and sense of agency.

On the basis of this study, it seems that humans either outcompeted Neanderthals for limited resources—driving them to extinction—or simply were better suited to survive than Neanderthals because of superior mental capabilities. Or perhaps their demise occurred for more sinister reasons. Maybe we used our sophisticated reasoning skills to kill off these creatures.

Did Neanderthals Make Art, Music, Jewelry, etc.?

Recently, a flurry of reports has appeared in the scientific literature claiming that Neanderthals possessed the capacity for language and the ability to make art, music, and jewelry. Other studies claim that Neanderthals ritualistically buried their dead, mastered fire, and used plants medicinally. All of these claims rest on highly speculative interpretations of the archaeological record. In fact, other studies present evidence that refutes every one of these claims (see Resources).

Comparisons of human and Neanderthal brain morphology and size become increasingly important in the midst of this controversy. This recent study—along with previous work (go here and here)—indicates that Neanderthals did not have the brain architecture and, hence, cognitive capacity to communicate symbolically through language, art, music, and body ornamentation. Nor did they have the brain capacity to engage in complex social interactions. In short, Neanderthal brain anatomy does not support any interpretation of the archaeological record that attributes advanced cognitive abilities to these creatures.

While this study provides important clues about the disappearance of Neanderthals, we still don’t know why they went extinct. Nor do we know any of the mysterious details surrounding their demise as a species.

Perhaps we will never know.

But we do know that in terms of our cognitive and social capacities, human beings stand apart from Neanderthals and all other creatures. Human brain biology and behavior render us exceptional, one-of-a-kind, in ways consistent with the image of God.

Resources

Endnotes

  1. Takanori Kochiyama et al., “Reconstructing the Neanderthal Brain Using Computational Anatomy,” Science Reports 8 (April 26, 2018): 6296, doi:10.1038/s41598-018-24331-0.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/09/19/differences-in-human-and-neanderthal-brains-explain-human-exceptionalism

Did Neanderthals Have the Brains to Make Art?

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BY FAZALE RANA – APRIL 4, 2018

Are you a left-brain or a right-brain person?

In the 1960s, Nobel laureate Roger W. Sperry advanced the idea of the split-brain, with each hemisphere involved in distinct activities. According to this model, the activities of the left hemisphere of the brain include thinking in words, logic, and mathematics while the right hemisphere’s activities include imagination, artistic expression, intuition, and feeling. The popular narrative is that some people, such as artists and musicians, have a more dominant right brain. And people such as scientists and engineers, have a dominant left brain. As it turns out, there is no truth to this idea. Although the activities of the two hemispheres differ, no evidence exists that one side of the brain is more dominant in some people than the other. In reality, both sides of the brain work together to carry out any task.

While there may not be any obvious differences in the brains of artists and scientists, there do appear to be some significant differences between the brains of modern humans and Neanderthals and, according to psychologist Richard Coss, these differences make it unlikely that Neanderthals had artistic capabilities.1

As discussed in Who Was Adam?, one of the differences between the brains of modern humans and Neanderthals is the size of the parietal lobe (cortex).2 The modern human brain has a much larger parietal lobe, contributing to the globular shape of our skull (compared to the elongated Neanderthal skull). This area of the brain is involved in the processing required for language and mathematics. It is also the part of the brain responsible for visuomotor coordination.

Coss argues that the underdeveloped parietal lobe of Neanderthals accounts for the differences in hunting practices between Neanderthals and modern humans. Neanderthals hunted easy-to-kill game that wouldn’t have been wary of their presence. This lack of wariness allowed these hominins to get close enough to the game to thrust their spears into them. On the other hand, the first modern humans hunted dangerous game that would have been cautious of their presence. Modern humans killed these animals from a distance by throwing spears at them. This special hunting practice requires a high degree of hand-eye coordination that is only possible because of our large parietal lobe.

Coss points out that the same degree of hand-eye coordination required to throw a spear is needed to make representative art. To make art, the first modern humans had to mentally visualize from memory animals that they had previously seen and then translate those mental images into highly coordinated hand-eye movements needed to etch, draw, and paint those animals. According to Coss, Neanderthals were not able to do this because of their underdeveloped parietal lobe. To put it simply, Neanderthals did not have the brain for art.

This insight has important implications for recent claims that Neanderthals made art, made music, possessed language, and displayed symbolic behavior, all of which require an enlarged parietal lobe. These claims of Neanderthal symbolism have all been questioned based on additional scientific scrutiny. This latest insight from Coss further justifies skepticism about the claims that Neanderthals displayed symbolism and advanced cognition like us. In fact, I would even go one step further. If these hominins didn’t have the brain structure to support artistic expression, then claims of Neanderthal symbolism should be dismissed altogether.

Many people view symbolism as a quality unique to human beings, contributing to our advanced cognitive abilities and a reflection of our exceptional nature—in ways that align with the image of God. In fact, as a Christian, I see symbolism as a manifestation of the image of God. Yet, if Neanderthals possessed symbolic capabilities, it would undermine human exceptionalism (and with it the biblical view of human nature), rendering human beings nothing more than another hominin.

But when the full body of scientific evidence about Neanderthal biology and behavior is carefully weighed, it becomes clear that human beings uniquely stand apart from all creatures. We are exceptional.

Resources

Endnotes
  1. Richard G. Coss, “Drawings of Representational Images by Upper Paleolithic Humans and Their Absence in Neanderthals Might Reflect Historical Differences in Hunting Wary Game,” Evolutionary Studies in Imaginative Culture 1 (2017): doi:10.26613/esic/1.2.46.
  2. Fazale Rana with Hugh Ross, Who Was Adam? A Creation Model Approach to the Origin of Humanity, 2nd ed. (Covina, CA: RTB Press, 2014): 200–201.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/04/04/did-neanderthals-have-the-brains-to-make-art

The Female Brain: Pregnant with Design

thefemalebrainpregnant

BY FAZALE RANA – JANUARY 25, 2017

When Jesus saw his mother there, and the disciple whom he loved standing nearby, he said to her, “Woman, here is your son.”

–John 19:26

I’ve learned the hard way: It is best to be circumspect when offering commentary about pregnancy, especially when women are around.

So, it’s with some hesitation I bring up the latest scientific insight developed by a team of researchers from Spain. These investigators discovered that pregnancy alters a woman’s brain. In fact, pregnancy reduces her grey matter.1 (Okay Fuz. Hold your tongue. Don’t say what you’re thinking.)

But, as it turns out, the loss of grey matter is a good thing. In fact, it reveals the elegant design of the human brain and adds to the growing evidence of human exceptionalism. This scientific advance also has implications for the pro-life movement.

The Spanish research team was motivated to study brain changes in pregnant women because of the effects that sex hormones have on adolescent brains. During this time, sex hormones cause extensive reorganization of the brain. This process is a necessary part of the neural maturation process. The researchers posited that changes to the female brain should take place, because of the surge of sex hormones during pregnancy. While pregnant, women are exposed to 10 to 15 times the “normal” progesterone levels. During nine months of pregnancy, women are also subjected to more estrogen than the rest of their life when not pregnant.

To characterize the effect of pregnancy on brain structure, the research team employed a prospective study design. They imaged the brains of women who wanted to become pregnant for the first time. Then, they imaged the brains of the subjects once the women had given birth. Finally, they imaged the brains of the subjects two years after birth, if they didn’t become pregnant again. As controls, they imaged the brains of women who had never been pregnant and the brains of the fathers.

The Effects of Pregnancy on Women’s Brains

While the brain’s white matter is unaffected, the researchers found that pregnancy leads to a loss of grey matter that, minimally, lasts up to two years. They also discovered that the grey matter loss was not random or arbitrary. Instead, it occurred in highly specific areas of the brain. In fact, the grey matter loss was so consistent from subject to subject that the researchers could tell if a woman was pregnant or not from brain images alone.

As it turns out, the area of the brain that loses grey matter is the region involved in social cognition that harbors the theory-of-mind neural network. This network allows human beings to display a quality anthropologists call theory of mind. Along with symbolism, our theory-of-mind capacity makes us unique compared to other animals, providing scientific justification for the idea of human exceptionalism. As human beings, we recognize that other humans possess a mind like ours. Because of that recognition, we can anticipate what others are thinking and feeling. Our theory-of-mind capability makes possible complex social interactions characteristic of our species.

Even though the pregnant women lost grey matter, they showed no loss of memory or cognitive ability. The researchers believe that the loss of grey matter stems from synaptic pruning. This process occurs in adolescents and is a vital part of brain development and maturation. Through the loss of grey matter, neural networks form. The research team posits that synaptic pruning in pregnant women establishes a neural network that plays a role in the deep attachment mothers have with their children. This attachment helps mothers anticipate their babies’ needs. The deep social connection between mother and child is critical for human survival, because human infants are so vulnerable at birth and have a prolonged childhood.

In support of this proposal, the researchers found that when they showed the pregnant women pictures of their babies, the brain areas that lost grey matter became active. On the other hand, they saw no corresponding brain activity when the mothers were shown pictures of other babies.

The Case for Human Exceptionalism Mounts

This work highlights the elegant design of human pregnancy and child rearing—features that I take as evidence for a Creator’s handiwork. It is nothing short of brilliant to have the surge of sex hormones during pregnancy, priming the brain to ensure a close attachment between mother and child, at the time of birth and throughout the first few years of childhood.

More importantly, this work adds to the mounting scientific evidence for human exceptionalism. Not only do humans uniquely possess theory of mind, but our theory-of-mind neural network is more complex and sophisticated than previously thought. It is remarkable that this neural network can be adapted and fine-tuned to ensure an intimate mother-infant attachment while maintaining relationships in the midst of complex social surroundings, typical of human interactions.

As an interesting side note: Recent research indicates that for Neanderthals, the area of their brain devoted to maintaining social interactions was much smaller than the corresponding area in modern humans, highlighting our unique and exceptional nature even when compared to the hominids found in the fossil record.2

Pro-Life Implications

In my view, this work also has pro-life implications. I frequently hear pro-choice advocates argue that the fetus is a mass of tissue, just like a tumor. But, this study undermines this view. It is hard to think of a fetus as being just a lump of tissue, when such a sophisticated system is in place during pregnancy to form a neural network (that is, a subset of the theory-of-mind network) in the mother’s brain that generates the special capacity of the mother to bond with the fetus at birth.

It also raises concerns for the health of women who receive abortions. Though speculative, one has to wonder what effect prematurely terminating a pregnancy has on women whose brains have become fine-tuned to bond to the very infants that are destroyed by the abortion.

Resources

Placenta Optimization Shows Creator’s Handiwork” by Fazale Rana (article)
Curvaceous Anatomy of the Female Spine Reveals Ingenious Obstetric Design” by Virgil Robertson (article)
Does the Childbirth Process Represent Clumsy Evolution or Good Engineering?” by Fazale Rana (article)
Neanderthal Brains Make Them Unlikely Social Networkers” by Fazale Rana (article)

Endnotes

  1. Elseline Hoekzema et al., “Pregnancy Leads to Long-Lasting Changes in Human Brain Structure,” Nature Neuroscience, published electronically December 19, 2016, doi:10.1038/nn.4458.
  2. Eiluned Pearce, Chris Stringer, and R. I. M. Dunbar, “New Insights into Differences in Brain Organization between Neanderthals and Anatomically Modern Humans,” Proceedings of the Royal Society B 280 (May 2013): doi:10.1098/rspb.2013.0168.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2017/01/25/the-female-brain-pregnant-with-design