Are Perforated Shells Evidence for Neanderthal Symbolism?

perforatedshells

BY FAZALE RANA – MARCH 28, 2018

When my kids were little, there was a good chance my wife and I would spend our Saturday afternoons hanging out at Chuck E. Cheese’s, while our children ran wild, celebrating the birthday of one of their friends. They loved it. My wife and I endured the chaos (and the mediocre pizza). Two things that helped me through those Saturday afternoons were:

  1. Watching Chuck E. Cheese sing the birthday song.
  2. Playing the gigantic version of whack-a-mole.

Little did I know then that my fondness for this arcade game would serve me well in my work at Reasons to Believe. Lately, it feels like I’m playing a never-ending game of whack-a-mole, responding to the steady stream of claims that Neanderthals possessed symbolism—claims that inevitably don’t stand up to scientific scrutiny.

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. As a Christian, I see symbolism as a manifestation of the image of God. Yet, if Neanderthals possessed symbolic capabilities, this feature would undermine human exceptionalism (and with it the biblical view of human nature), possibly rendering human beings nothing more than another hominin.

The most recent claim of Neanderthal “symbolism” comes from a research team headed up by the Portuguese archeologist João Zilhão. Based on the dating of a flowstone that caps a deposit from the Cueva de los Aviones site in southeast Spain, these investigators argue that Neanderthals must have possessed symbolism nearly 40,000 years before modern humans displayed this property.1 The researchers age-dated the flowstone, using U and Th isotopes, to about 115,000 to 200,00 years in age. This date indicated to the researchers that the deposits must have been produced by Neanderthals, the only hominins in Iberia at the time. The deposits also harbored several other elements that convinced the researchers of Neanderthals’ capacity for symbolism: (1) red and yellow colorants, (2) ochred and perforated marine shells, and (3) shell containers with residues of pigmentatious materials.

Still, Some Questions Remain . . .

At first glance, the research team’s case for Neanderthal symbolism seems compelling, but with a little additional scientific scrutiny, things become much more muddled.

  • For example, the age of the materials at the Cueva de los Aviones site may well be much younger than 115,000 to 200,000 years in age. An earlier study used radiocarbon methods to age-date food shells at this site to be only 45,000 to 50,000 years old. This dating lines up with the arrival of the first modern humans in Europe.2 While the authors of the most recent study dismiss the younger age, arguing that the amount of the radiocarbon in the shells is at the cusp of the method’s detection limits, this concern does not mean that the radiocarbon result is inaccurate. In fact, I would maintain that it is better to determine the age of the artifacts by directly determining the age-date of specimens taken from the deposit than to try to infer the artifacts’ age from complex geological structures associated with the deposit. Moreover, U/Th dating is susceptible to the influence of water flowing through the system. U is water soluble and Th is not. This difference in solubility means that water flow will remove U from the system, making the sample appear to be older than it is. In other words, geologists must make sure that the flowstone is a closed system before regarding the U/Th-determined age of the flowstone to be secure.
  • Another point of concern has to do with whether or not the pigments and the ochred and perforated marine shells at the Cueva de los Aviones site are a reliable indicator of symbolism. Some archaeologists question whether the mere presence of ochre and other pigment materials at a site reflects symbolic capabilities. For example, one research team that also discovered red ochre at a Neanderthal site, dating to 200,000 years in age, concluded: “In our view, there is no reason to assume that the mere presence of iron oxide at an archaeological site, whether Neanderthal or modern human, implies symbolic behavior.”3 Likewise, the perforation of marine shells does not reflect intentional activity on the part of Neanderthals (or even modern humans). A research team from Poland and the UK have shown that predatory mollusks cause the same type of perforations as humans/hominins and at the same locations on the shell surfaces.4

So, given these concerns, it becomes difficult to conclude with any certainty that Neanderthals displayed symbolism based on this most recent study.

Does the Weight of Archaeological Evidence Support Neanderthal Symbolism?

To be certain, the scientific literature is replete with claims that Neanderthals buried their dead, made art and jewelry, mastered fire, made glue, etc. Hence, some scientists argue that Neanderthals displayed symbolic capabilities and advanced cognitive abilities, just like modern humans. Yet, every one of these claims is disputed and they do not withstand ongoing scientific scrutiny. (See the Resources section below.)

In fact, when the Neanderthal archaeological record is considered in its entirety (the isolated and disputed claims of advanced cognition notwithstanding), a clear and cohesive picture emerges about Neanderthal behavior. Though remarkable creatures, they did not have cognitive abilities on par with modern humans. These creatures were nothing like us.

Ian Tattersall and Noam Chomsky have pointed out that the Neanderthal archaeological record displays little evidence of technological innovation. Neanderthal technology remained largely static from the time they first appeared (around 250,000 to 200,000 years ago) to the time they went extinct (around 40,000 years ago). In contradistinction, an exponential growth in modern human technology has taken place since our inception as a species. According to Tattersall and Chomsky, this explosive rate of innovation is only possible because of our symbolic capacity and is clear evidence that Neanderthals lacked symbolism.5

Are Archaeologists Biased against Human Exceptionalism?

So, then, why are so many claims of Neanderthal symbolism published in the scientific literature? I am of the opinion that these claims are motivated by a desire to undermine the notion of human exceptionalism. It has become increasingly commonplace in some scientific circles to condemn anyone who argues for human exceptionalism as committing an outrageous act of speciesism (with speciesism on par with racism). And what better way to undermine the notion of human exceptionalism and to promote species equality than to make Neanderthals appear just like us?

Unfortunately, the limited archaeological data makes it easy to claim that Neanderthals displayed symbolism—even if they didn’t. As science writer Jon Mooallem has pointed out:

“. . . 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 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.6″

Given this tendency in anthropology, one has to wonder how much an antihuman bias and a commitment to the metanarrative of Neanderthal exceptionalism influences interpretation of the archaeological record. Also, how much do these biases fuel claims about Neanderthal symbolism?

In fact, archaeologist João Zilhão, who headed up the research team that redated the Cueva de los Aviones site, is a well-known champion for Neanderthal exceptionalism.7 Science writer Michael Balter has described Zilhão as “the Neanderthal’s fiercest advocate, taking on any and all suggestions that their mental abilities might have been inferior to those of modern humans.”8 Anthropologists have accused Zilhão and his oft-collaborator Erik Trinkaus of treating Neanderthals as a “stone age minority group in need of affirmative action.”9 In fact, Zilhão’s bias is well-known by other anthropologists. Jean-Jacques Hublin from the Max Planck Institute for Evolutionary Anthropology sees Zilhão on the equivalent of a mission from God. Referring to Zilhão, Hublin notes, “Those who are on a mission from God . . . are those who try to deny any evidence not matching with their personal crusade. The latest debates about Neanderthal abilities are one of the worst examples in which ideological issues have overshadowed scientific advance.”10

Published claims that Neanderthals possessed advanced cognitive capacities like humans usually receive quite a bit of fanfare. However, as in the game of whack-a-mole, once the evidence is carefully examined it doesn’t stand up to scrutiny. Claims of Neanderthal symbolism are almost always made based on a single, isolated find and they arise from highly speculative interpretations of the data at hand. When the full body of scientific evidence about Neanderthal biology and behavior is carefully weighed, it seems highly unlikely that these creatures possessed cognitive capacities on par with modern humans.

Resources

Endnotes

  1. Dirk L. Hoffman et al., “Symbolic Use of Marine Shells and Mineral Pigments by Iberian Neandertals 115,000 Years Ago,” Science Advances 4 (February 22, 2018): eaar5255, doi:10.1126/sciadv.aar5255.
  2. João Zilhão et al., “Symbolic Use of Marine Shells and Mineral Pigments by Iberian Neandertals,” Proceedings of the National Academy of Sciences USA 107 (January 19, 2010): 1023–28, doi:10.1073/pnas.0914088107.
  3. Wil Roebroeks et al., “Use of Red Ochre by Early Neandertals,” Proceedings of the National Academy of Sciences USA 109 (February 7, 2012): 1893, doi:10.1073/pnas.1112261109.
  4. Anna Maria Kubicka et al., “A Systematic Review of Animal Predation Creating Pierced Shells: Implications for the Archaeological Record of the Old World,” PeerJ 5 (2017): e2903, doi:10.7717/peerj.2903.
  5. Johan J. Bolhuis et al., “How Could Language Have Evolved?”, PLoS Biology 12 (August 26, 2014): e1001934, doi:10.1371/journal.pbio.1001934.
  6. 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.
  7. Michael Balter, “Neandertal Champion Defends the Reputation of Our Closest Cousins,” Science 337 (August 10, 2012): 642–43, doi:10.1126/science.337.6095.642.
  8. Balter, “Neandertal Champion.”
  9. Balter, “Neandertal Champion.”
  10. Balter, “Neandertal Champion.”
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/03/28/are-perforated-shells-evidence-for-neanderthal-symbolism

Believing Impossible Things: Convergent Origins of Functional Junk DNA Sequences

believingimpossiblethings

BY FAZALE RANA – MARCH 14, 2018

In a classic scene from Alice in Wonderland, the story’s heroine informs the White Queen, “One can’t believe impossible things,” to which, the White Queen—scolding Alice—replies, “I daresay you haven’t had much practice. When I was your age, I always did it for half-an-hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”

If recent work by researchers from UC Santa Cruz and the University of Rochester (New York) is to be taken as true, it would require evolutionary biologists to believe two impossible things—before, during, and after breakfast. These scientific investigators have discovered something that is hard to believe about the role SINE DNA plays in gene regulation, raising questions about the validity of the evolutionary explanation for the architecture of the human genome.1 In fact, considering the implications of this work, it would be easier to believe that the human genome was shaped by a Creator’s handiwork than by evolutionary forces.

SINE DNA

One of the many classes of noncoding or junk DNA, short interspersed elements, or SINE DNA sequences, range in size from 100 to 300 base pairs (genetic letters). In primates, the most common SINEs are the Alu sequences. There are about 1.1 million Alu copies in the human genome (roughly 12 percent of the genome).

SINE DNA sequences (including Alu sequences) contain a DNA segment used by the cell’s machinery to produce an RNA message. This feature allows SINEs to be transcribed. Because of this feature, molecular biologists also categorize SINE DNA as a retroposon. Molecular biologists believe that SINE sequences can multiply in number within an organism’s genome through the activity of the enzyme, reverse transcriptase. Presumably, once SINE DNA becomes transcribed, reverse transcriptase converts SINE RNA back into DNA. The reconverted DNA sequence then randomly reintegrates back into the genome. It’s through this duplication and reintegration mechanism that SINE sequences proliferate as they move around, or retrotranspose, throughout the genome. To say it differently, molecular biologists believe that over time, transcription of SINE DNA and reverse transcription of SINE RNA increases the copy number of SINE sequences and randomly disperses them throughout an organism’s genome.

Molecular biologists have discovered numerous instances in which nearly identical SINE segments occur at corresponding locations in the genomes of humans, chimpanzees, and other primates. Because the duplication and movement of SINE DNA appear to be random, evolutionary biologists think it unlikely that SINE sequences would independently appear in the same locations in the genomes of humans and chimpanzees (and other primates). And given their supposed nonfunctional nature, shared SINE DNA in humans and chimpanzees seemingly reflects their common evolutionary ancestry. In fact, evolutionary biologists have gone one step further, using SINE Alu sequences to construct primate evolutionary trees.

SINE DNA Is Functional

Even though many people view shared junk DNA sequences as the most compelling evidence for biological evolution, the growing recognition that virtually every class of junk DNA has function undermines this conclusion. For if these shared sequences are functional, then one could argue that they reflect the Creator’s common design, not shared evolutionary ancestry and common descent. As a case in point, in recent years, molecular biologists have learned that SINE DNA plays a vital role in gene regulation through a variety of distinct mechanisms.2

Staufen-Mediated mRNA Decay

One way SINE sequences regulate gene expression is through a pathway called Staufen-mediated messenger RNA (mRNA) decay (SMD). Critical to an organism’s development, SMD plays a key role in cellular differentiation. SMD is characterized by a complex mechanism centered around the destruction of mRNA. When this degradation takes place, it down-regulates gene expression. The SMD pathway involves binding of a protein called Staufen-1 to one of the ends of the mRNA molecule (dubbed the 3´untranslated region). Staufen-1 binds specifically to double-stranded structures in the 3´untranslated region. This double strand structure forms when Alu sequences in the 3´untranslated region bind to long noncoding RNA molecules containing Alu sequences. This binding event triggers a cascade of additional events that leads to the breakdown of messenger RNA.

Common Descent or Common Design?

As an old-earth creationist, I see the functional role played by noncoding DNA sequences as a reflection of God’s handiwork, defending the case for design from a significant evolutionary challenge. To state it differently: these findings mean that it is just as reasonable to conclude that the shared SINE sequences in the genomes of humans and the great apes reflect common design, not a shared evolutionary ancestry.

In fact, I would maintain that it is more reasonable to think that functional SINE DNA sequences reflect common design, rather than common descent, given the pervasive role these sequence elements play in gene regulation. Because Alu sequences are only found in primates, they must have originated fairly recently (when viewed from an evolutionary framework). Yet, they play an integral and far-reaching role in gene regulation.

And herein lies the first impossible thing evolutionary biologists must believe: Somehow Alusequences arose and then quickly assumed a central place in gene regulation. According to Carl Schmid, a researcher who uncovered some of the first evidence for the functional role played by SINE DNA, “Sine Alus have appeared only recently within the primate lineage, this proposal [of SINE DNA function] provokes the challenging question of how Alu RNA could have possibly assumed a significant role in cell physiology.”3

How Does Junk DNA Acquire Function?

Still, those who subscribe to the evolutionary framework do not view functional junk DNA as incompatible with common descent. They argue that junk DNA acquired function through a process called neofunctionalization. In the case of SMD mediated by Alu sequences in the human genome, evolutionary biologists maintain that occasionally these DNA elements will become incorporated into the 3´untranslated regions of genes and regions of the human genome that produce long noncoding RNAs, and, occasionally, by chance, some of the Alusequences in long noncoding RNAs will have the capacity to pair with the 3´untranslated region of specific mRNAs. When this happens, these Alu sequences trigger SMD-mediated gene regulation. And if this gene regulation has any advantage, it will persist so that over time, some Alu sequences will eventually evolve to assume a role in SMD-mediated gene regulation.

Is Neofunctionalization the Best Explanation for SINE Function?

At some level, this evolutionary scenario seems reasonable (the concerns expressed by Carl Schmid notwithstanding). Still, neofunctionalization events should be relatively rare. And because of the chance nature of neofunctionalization, it would be rational to think that the central role SINE sequences play in SMD gene regulation would be unique to humans.

Why would I make this claim? Based on the nature of evolutionary mechanisms, chance should govern biological and biochemical evolution at its most fundamental level (assuming it occurs). Evolutionary pathways consist of a historical sequence of chance genetic changes operated on by natural selection, which also consists of chance components. The consequences are profound. If evolutionary events could be repeated, the outcome would be dramatically different every time. The inability of evolutionary processes to retrace the same path makes it highly unlikely that the same biological and biochemical designs should appear repeatedly throughout nature.

The concept of historical contingency embodies this idea and is the theme of Stephen Jay Gould’s book Wonderful Life. According to Gould,

“No finale can be specified at the start, none would ever occur a second time in the same way, because any pathway proceeds through thousands of improbable stages. Alter any early event, ever so slightly, and without apparent importance at the time, and evolution cascades into a radically different channel.”4

To help clarify the concept of historical contingency, Gould used the metaphor of “replaying life’s tape.” If one were to push the rewind button, erase life’s history, and let the tape run again, the results would be completely different each time. The very essence of the evolutionary process renders evolutionary outcomes nonrepeatable.

Gould’s perspective of the evolutionary process has been affirmed by other researchers who have produced data, indicating that if evolutionary processes explain the origin of biochemical systems, they must be historically contingent.

Did SMD Evolve Twice?

Yet, collaborators from UC Santa Cruz and the University of Rochester discovered that SINE-mediated SMD appears to have evolved independently—two separate times—in humans and mice, the second impossible thing evolutionary biologists have to believe.

Though rodents don’t possess Alu sequences, they do possess several other SINE elements, labeled B1, B2, B4, and ID. Remarkably, these B/ID sequences occur in regions of the mouse genome corresponding to regions of the human-harboring Alu sequences. And, when the B/ID sequences are associated with the 3´untranslated regions of genes, the mRNA produced from these genes is down-regulated, suggesting that these genes are under the influence of the SMD-mediated pathway—an unexpected result.

But, this finding is not nearly as astonishing as something else the research team discovered. By comparing about 1,200 human-mouse gene pairs in myoblasts, the researchers discovered 24 genes in this cell type that were identical in the human and mouse genomes. These identical genes performed the same physiological role and possessed SINE elements (Alu and B/ID, respectively) and were regulated by the SMD mechanism.

Evolutionary biologists believe that Alu and B/ID SINE sequences emerged independently in the rodent and human lineages. If so, this means that the evolutionary processes must have independently produced the identical outcome—SINE-mediated SMD gene regulation—24 separate times for each of the 24 identical genes. As the researchers point out, chance alone cannot explain their findings. Yet, evolutionary mechanisms are historically contingent and should not yield identical outcomes. This impossible scenario causes me to question if neofunctionalization is the explanation for functional SINE DNA.

And yet, this is not the first time that life scientists have discovered the independent emergence of identical function for junk DNA sequences.

So, which is the better explanation for functional junk DNA sequences: neofunctionalization through historically contingent evolutionary processes or the work of a Mind?

As Alice emphatically complained, “One can’t believe impossible things.”

Resources

Endnotes

  1. Brownyn A. Lucas et al., “Evidence for Convergent Evolution of SINE-Directed Staufen-Mediated mRNA Decay,” Proceedings of the National Academy of Sciences, USA Early Edition (January 2018): doi:10.1073/pnas.1715531115.
  2. Reyad A. Elbarbary et al., “Retrotransposons as Regulators of Gene Function,” Science 351 (February 12, 2016): doi:10.1126/science.aac7247.
  3. Carl W. Schmid, “Does SINE Evolution Preclude Alu Function?” Nucleic Acid Research 26 (October 1998): 4541–50, doi:10.1093/nar/26.20.4541.
  4. Stephen Jay Gould, Wonderful Life: The Burgess Shale and the Nature of History (New York: W. W. Norton & Company, 1989), 51.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/03/14/believing-impossible-things-convergent-origins-of-functional-junk-dna-sequences