Endosymbiont Hypothesis and the Ironic Case for a Creator

endosymbionthypothesisandtheironic

BY FAZALE RANA – DECEMBER 12, 2018

i ·ro ·ny

The use of words to express something different from and often opposite to their literal meaning.
Incongruity between what might be expected and what actually occurs.

—The Free Dictionary

People often use irony in humor, rhetoric, and literature, but few would think it has a place in science. But wryly, this has become the case. Recent work in synthetic biology has created a real sense of irony among the scientific community—particularly for those who view life’s origin and design from an evolutionary framework.

Increasingly, life scientists are turning to synthetic biology to help them understand how life could have originated and evolved. But, they have achieved the opposite of what they intended. Instead of developing insights into key evolutionary transitions in life’s history, they have, ironically, demonstrated the central role intelligent agency must play in any scientific explanation for the origin, design, and history of life.

This paradoxical situation is nicely illustrated by recent work undertaken by researchers from Scripps Research (La Jolla, CA). Through genetic engineering, the scientific investigators created a non-natural version of the bacterium E. coli. This microbe is designed to take up permanent residence in yeast cells. (Cells that take up permanent residence within other cells are referred to as endosymbionts.) They hope that by studying these genetically engineered endosymbionts, they can gain a better understanding of how the first eukaryotic cells evolved. Along the way, they hope to find added support for the endosymbiont hypothesis.1

The Endosymbiont Hypothesis

Most biologists believe that the endosymbiont hypothesis (symbiogenesis) best explains one of the key transitions in life’s history; namely, the origin of complex cells from bacteria and archaea. Building on the ideas of Russian botanist Konstantin Mereschkowski, Lynn Margulis(1938–2011) advanced the endosymbiont hypothesis in the 1960s to explain the origin of eukaryotic cells.

Margulis’s work has become an integral part of the evolutionary paradigm. Many life scientists find the evidence for this idea compelling and consequently view it as providing broad support for an evolutionary explanation for the history and design of life.

According to this hypothesis, complex cells originated when symbiotic relationships formed among single-celled microbes after free-living bacterial and/or archaeal cells were engulfed by a “host” microbe. Presumably, organelles such as mitochondria were once endosymbionts. Evolutionary biologists believe that once engulfed by the host cell, the endosymbionts took up permanent residency, with the endosymbiont growing and dividing inside the host.

Over time, the endosymbionts and the host became mutually interdependent. Endosymbionts provided a metabolic benefit for the host cell—such as an added source of ATP—while the host cell provided nutrients to the endosymbionts. Presumably, the endosymbionts gradually evolved into organelles through a process referred to as genome reduction. This reduction resulted when genes from the endosymbionts’ genomes were transferred into the genome of the host organism.

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Figure 1: Endosymbiont hypothesis. Image credit: Wikipedia.

Life scientists point to a number of similarities between mitochondria and alphaproteobacteria as evidence for the endosymbiont hypothesis. (For a description of the evidence, see the articles listed in the Resources section.) Nevertheless, they don’t understand how symbiogenesis actually occurred. To gain this insight, scientists from Scripps Research sought to experimentally replicate the earliest stages of mitochondrial evolution by engineering E. coli and brewer’s yeast (S. cerevisiae) to yield an endosymbiotic relationship.

Engineering Endosymbiosis

First, the research team generated a strain of E. coli that no longer has the capacity to produce the essential cofactor thiamin. They achieved this by disabling one of the genes involved in the biosynthesis of the compound. Without this metabolic capacity, this strain becomes dependent on an exogenous source of thiamin in order to survive. (Because the E. coli genome encodes for a transporter protein that can pump thiamin into the cell from the exterior environment, it can grow if an external supply of thiamin is available.) When incorporated into yeast cells, the thiamin in the yeast cytoplasm becomes the source of the exogenous thiamin, rendering E. coli dependent on the yeast cell’s metabolic processes.

Next, they transferred the gene that encodes a protein called ADP/ATP translocase into the E. coli strain. This gene was harbored on a plasmid (which is a small circular piece of DNA). Normally, the gene is found in the genome of an endosymbiotic bacterium that infects amoeba. This protein pumps ATP from the interior of the bacterial cell to the exterior environment.2

The team then exposed yeast cells (that were deficient in ATP production) to polyethylene glycol, which creates a passageway for E. coli cells to make their way into the yeast cells. In doing so, E. coli becomes established as endosymbionts within the yeast cells’ interior, with the E. coli providing ATP to the yeast cell and the yeast cell providing thiamin to the bacterial cell.

Researchers discovered that once taken up by the yeast cells, the E. coli did not persist inside the cell’s interior. They reasoned that the bacterial cells were being destroyed by the lysosomal degradation pathway. To prevent their destruction, the research team had to introduce three additional genes into the E. coli from three separate endosymbiotic bacteria. Each of these genes encodes proteins—called SNARE-like proteins—that interfere with the lysosomal destruction pathway.

Finally, to establish a mutualistic relationship between the genetically-engineered strain of E. coli and the yeast cell, the researchers used a yeast strain with defective mitochondria. This defect prevented the yeast cells from producing an adequate supply of ATP. Because of this limitation, the yeast cells grow slowly and would benefit from the E. coli endosymbionts, with the engineered capacity to transport ATP from their cellular interior to the exterior environment (the yeast cytoplasm.)

The researchers observed that the yeast cells with E. coli endosymbionts appeared to be stable for 40 rounds of cell doublings. To demonstrate the potential utility of this system to study symbiogenesis, the research team then began the process of genome reduction for the E. coli endosymbionts. They successively eliminated the capacity of the bacterial endosymbiont to make the key metabolic intermediate NAD and the amino acid serine. These triply-deficient E. coli strains survived in the yeast cells by taking up these nutrients from the yeast cytoplasm.

Evolution or Intentional Design?

The Scripps Research scientific team’s work is impressive, exemplifying science at its very best. They hope that their landmark accomplishment will lead to a better understanding of how eukaryotic cells appeared on Earth by providing the research community with a model system that allows them to probe the process of symbiogenesis. It will also allow them to test the various facets of the endosymbiont hypothesis.

In fact, I would argue that this study already has made important strides in explaining the genesis of eukaryotic cells. But ironically, instead of proffering support for an evolutionary origin of eukaryotic cells (even though the investigators operated within the confines of the evolutionary paradigm), their work points to the necessary role intelligent agency must have played in one of the most important events in life’s history.

This research was executed by some of the best minds in the world, who relied on a detailed and comprehensive understanding of biochemical and cellular systems. Such knowledge took a couple of centuries to accumulate. Furthermore, establishing mutualistic interactions between the two organisms required a significant amount of ingenuity—genius that is reflected in the experimental strategy and design of their study. And even at that point, execution of their experimental protocols necessitated the use of sophisticated laboratory techniques carried out under highly controlled, carefully orchestrated conditions. To sum it up: intelligent agency was required to establish the endosymbiotic relationship between the two microbes.

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Figure 2: Lab researcher. Image credit: Shutterstock.

Or, to put it differently, the endosymbiotic relationship between these two organisms was intelligently designed. (All this work was necessary to recapitulate only the presumed first step in the process of symbiogenesis.) This conclusion gains added support given some of the significant problems confronting the endosymbiotic hypothesis. (For more details, see the Resources section.) By analogy, it seems reasonable to conclude that eukaryotic cells, too, must reflect the handiwork of a Divine Mind—a Creator.

Resources

Endnotes

  1. Angad P. Mehta et al., “Engineering Yeast Endosymbionts as a Step toward the Evolution of Mitochondria,” Proceedings of the National Academy of Sciences, USA 115 (November 13, 2018): doi:10.1073/pnas.1813143115.
  2. ATP is a biochemical that stores energy used to power the cell’s operation. Produced by mitochondria, ATP is one of the end products of energy harvesting pathways in the cell. The ATP produced in mitochondria is pumped into the cell’s cytoplasm from within the interior of this organelle by an ADP/ATP transporter.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/12/12/endosymbiont-hypothesis-and-the-ironic-case-for-a-creator

Did Neanderthals Start Fires?

neanderthalsstartfire

BY FAZALE RANA – DECEMBER 5, 2018

It is one of the most iconic Christmas songs of all time.

Written by Bob Wells and Mel Torme in the summer of 1945, “The Christmas Song” (subtitled “Chestnuts Roasting on an Open Fire”) was crafted in less than an hour. As the story goes, Wells and Torme were trying to stay cool during the blistering summer heat by thinking cool thoughts and then jotting them down on paper. And, in the process, “The Christmas Song” was born.

Many of the song’s lyrics evoke images of winter, particularly around Christmastime. But none has come to exemplify the quiet peace of a Christmas evening more than the song’s first line, “Chestnuts roasting on an open fire . . . ”

Gathering around the fire to stay warm, to cook food, and to share in a community has been an integral part of the human experience throughout history—including human prehistory. Most certainly our ability to master fire played a role in our survival as a species and in our ability as human beings to occupy and thrive in some of the world’s coldest, harshest climates.

But fire use is not limited only to modern humans. There is strong evidence that Neanderthals made use of fire. But, did these creatures have control over fire in the same way we do? In other words, did Neanderthals master fire? Or, did they merely make opportunistic use of natural fires? These questions are hotly debated by anthropologists today and they contribute to a broader discussion about the cognitive capacity of Neanderthals. Part of that discussion includes whether these creatures were cognitively inferior to us or whether they were our intellectual equals.

In an attempt to answer these questions, a team of researchers from the Netherlands and France characterized the microwear patterns on bifacial (having opposite sides that have been worked on to form an edge) tools made from flint recovered from Neanderthal sites, and concluded that the wear patterns suggest that these hominins used pyrite to repeatedly strike the flint. This process generates sparks that can be used to start fires.1 To put it another way, the researchers concluded that Neanderthals had mastery over fire because they knew how to start fires.

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Figure 1: Biface tools for cutting or scraping. Image credit: Shutterstock

However, a closer examination of the evidence along with results of other studies, including recent insight into the cause of Neanderthal extinction, raises significant doubts about this conclusion.

What Do the Microwear Patterns on Flint Say?

The investigators focused on the microwear patterns of flint bifaces recovered from Neanderthal sites as a marker for fire mastery because of the well-known practice among hunter-gatherers and pastoralists of striking flint with pyrite (an iron disulfide mineral) to generate sparks to start fires. Presumably, the first modern humans also used this technique to start fires.

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Figure 2: Starting a fire with pyrite and flint. Image credit: Shutterstock

The research team reasoned that if Neanderthals started fires, they would use a similar tactic. Careful examination of the microwear patterns on the bifaces led the research team to conclude that these tools were repeatedly struck by hard materials, with the strikes all occurring in the same direction along the bifaces’ long axis.

The researchers then tried to experimentally recreate the microwear pattern in a laboratory setting. To do so, they struck biface replicas with a number of different types of materials, including pyrites, and concluded that the patterns produced by the pyrite strikes most closely matched the patterns on the bifaces recovered from Neanderthal sites. On this basis, the researchers claim that they have found evidence that Neanderthals deliberately started fires.

Did Neanderthals Master Fire?

While this conclusion is possible, at best this study provides circumstantial, not direct, evidence for Neanderthal mastery of fire. In fact, other evidence counts against this conclusion. For example, bifaces with the same type of microwear patterns have been found at other Neanderthal sites, locales that show no evidence of fire use. These bifaces would have had a range of usages, including butchery of the remains of dead animals. So, it is possible that these tools were never used to start fires—even at sites with evidence for fire usage.

Another challenge to the conclusion comes from the failure to detect any pyrite on the bifaces recovered from the Neanderthal sites. Flint recovered from modern human sites shows visible evidence of pyrite. And yet the research team failed to detect even trace amounts of pyrite on the Neanderthal bifaces during the course of their microanalysis.

This observation raises further doubt about whether the flint from the Neanderthal sites was used as a fire starter tool. Rather, it points to the possibility that Neanderthals struck the bifaces with materials other than pyrite for reasons not yet understood.

The conclusion that Neanderthals mastered fire also does not square with results from other studies. For example, a careful assessment of archaeological sites in southern France occupied by Neanderthals from about 100,000 to 40,000 years ago indicates that Neanderthals could not create fire. Instead, these hominins made opportunistic use of natural fire when it was available to them.2

These French sites do show clear evidence of Neanderthal fire use, but when researchers correlated the archaeological layers displaying evidence for fire use with the 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 mastered fire.

Lightning strikes that would generate natural fires are much more likely to occur during warm periods. Instead of creating fire, Neanderthals most likely harnessed natural fire and cultivated it as long as they could before it extinguished.

Another study also raises questions about the ability of Neanderthals to start fires.3 This research indicates that cold climates triggered Neanderthal extinctions. By studying the chemical composition of stalagmites in two Romanian caves, an international research team concluded that there were two prolonged and extremely cold periods between 44,000 and 40,000 years ago. (The chemical composition of stalagmites varies with temperature.)

The researchers also noted that during these cold periods, the archaeological record for Neanderthals disappears. They interpret this disappearance to reflect a dramatic reduction in Neanderthal population numbers. Researchers speculate that when this population downturn took place during the first cold period, modern humans made their way into Europe. Being better suited for survival in the cold climate, modern human numbers increased. When the cold climate mitigated, Neanderthals were unable to recover their numbers because of the growing populations of modern humans in Europe. Presumably, after the second cold period, Neanderthal numbers dropped to the point that they couldn’t recover, and hence, became extinct.

But why would modern humans be more capable than Neanderthals of surviving under extremely cold conditions? It seems as if it should be the other way around. Neanderthals had a hyper-polar body design that made them ideally suited to withstand cold 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. But, despite this advantage, Neanderthals died out and modern humans thrived.

Some anthropologists believe that the survival discrepancy could be due to dietary differences. Some data indicates that modern humans had a more varied diet than Neanderthals. Presumably, these creatures primarily consumed large herbivores—animals that disappeared when the climatic conditions turned cold, thereby threatening Neanderthal survival. On the other hand, modern humans were able to adjust to the cold conditions by shifting their diets.

But could there be a different explanation? Could it be that with their mastery of fire, modern humans were able to survive cold conditions? And did Neanderthals die out because they could not start fires?

Taken in its entirety, the data seems to indicate that Neanderthals lacked mastery of fire but could use it opportunistically. And, in a broader context, the data indicates that Neanderthals were cognitively inferior to humans.

What Difference Does It Make?

One of the most important ideas taught in Scripture is that human beings uniquely bear God’s image. As such, every human being has immeasurable worth and value. And because we bear God’s image, we can enter into a relationship with our Maker.

However, if Neanderthals possessed advanced cognitive ability just like that of modern humans, then it becomes difficult to maintain the view that modern humans are unique and exceptional. If human beings aren’t exceptional, then it becomes a challenge to defend 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. Now it’s time to light a fire in my fireplace and enjoy a few contemplative moments thinking about the real meaning of Christmas.

Resources

Endnotes

  1. A. C. Sorensen, E. Claud, and M. Soressi, “Neanderthal Fire-Making Technology Inferred from Microwear Analysis,” Scientific Reports 8 (July 19, 2018): 10065, doi:10.1038/s41598-018-28342-9.
  2. 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.1106759108; Paul 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 Neandertal 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.
  3. Michael Staubwasser et al., “Impact of Climate Change on the Transition of Neanderthals to Modern Humans in Europe,” Proceedings of the National Academy of Sciences, USA 115 (September 11, 2018): 9116–21, doi:10.1073/pnas.1808647115.

Further Review Overturns Neanderthal Art Claim

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BY FAZALE RANA – OCTOBER 17, 2018

As I write this blog post, the 2018–19 NFL season is just underway.

During the course of any NFL season, several key games are decided by a controversial call made by the officials. Nobody wants the officials to determine the outcome of a game, so the NFL has instituted a way for coaches to challenge calls on the field. When a call is challenged, part of the officiating crew looks at a computer tablet on the sidelines—reviewing the game footage from a number of different angles in an attempt to get the call right. After two minutes of reviewing the replays, the senior official makes his way to the middle of the field and announces, “Upon further review, the call on the field . . .”

Recently, a team of anthropologists from Spain and the UK created quite a bit of controversy based on a “call” they made from working in the field. Using a new U-Th dating method, these researchers age-dated the artwork in caves from Iberia. Based on the age of a few of their samples, they concluded that Neanderthals produced cave paintings.1 But new work by three independent research teams challenges the “call” from the field—overturning the conclusion that Neanderthals made art and displayed symbolism like modern humans.

U-Th Dating Method

The new dating method under review measures the age of calcite deposits beneath cave paintings and those formed over the artwork after the paintings were created. As water flows down cave walls, it deposits calcite. When calcite forms, it contains trace amounts of U-238. This isotope decays into Th-230. Normally, detection of such low quantities of the isotopes would require extremely large samples. Researchers discovered that by using accelerator mass spectrometry, they could get by with 10-milligram samples. And by dating the calcite samples with this technique, they produced minimum and maximum ages for the cave paintings.2

Call from the Field: Neanderthals Are Artists

The team applied their dating method to the art found in three cave sites in Iberia (ancient Spain): (1) La Pasiega, which houses paintings of animals, linear signs, claviform signs, and dots; (2) Ardales, which contains about 1,000 paintings of animals, along with dots, discs, lines, geometric shapes, and hand stencils; and (3) Maltravieso, which displays a set of hand stencils and geometric designs. The research team took a total of 53 samples from 25 carbonate formations associated with the cave art in these three cave sites. While most of the samples dated to 40,000 years old or less (which indicates that modern humans were the artists), three measurements produced minimum ages of around 65,000 years, including: (1) red scalariform from La Pasiega, (2) red areas from Ardales, and (3) a hand stencil from Maltravieso. On the basis of the three measurements, the team concluded that the art must have been made by Neanderthals because modern humans had not made their way into Iberia at that time. In other words, Neanderthals made art, just like modern humans did.

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Figure: Maltravieso Cave Entrance, SpainImage credit: Shutterstock

Shortly after the findings were published, I wrote a piece expressing skepticism about this claim for two reasons.

First, I questioned the reliability of the method. Once the calcite deposit forms, the U-Th method will only yield reliable results if none of the U or Th moves in or out of the deposit. Based on the work of researchers from France and the US, it does not appear as if the calcite films are closed systems. The calcite deposits on the cave wall formed because of hydrological activity in the cave. Once a calcite film forms, water will continue to flow over its surface, leeching out U (because U is much more water soluble than Th). By removing U, water flowing over the calcite will make it seem as if the deposit and, hence, the underlying artwork is much older than it actually is.3

Secondly, I expressed concern that the 65,000-year-old dates measured for a few samples are outliers. Of the 53 samples measured, only three gave age-dates of 65,000 years. The remaining samples dated much younger, typically around 40,000 years in age. So why should we give so much credence to three measurements, particularly if we know that the calcite deposits are open systems?

Upon Further Review: Neanderthals Are Not Artists

Within a few months, three separate research groups published papers challenging the reliability of the U-Th method for dating cave art and, along with it, the claim that Neanderthals produced cave art.4 It is not feasible to detail all their concerns in this article, but I will highlight six of the most significant complaints. In several instances, the research teams independently raised the same concerns.

  1. The U-Th method is unreliable because the calcite deposits are an open system. The concern that I raised was reiterated by two of the research teams for the same reason I expressed. The U-Th dating technique can only yield reliable results if no U or Th moves in or out of the system once the calcite film forms. The continued water flow over the calcite deposits will preferentially leech U from the deposit, making the deposit appear to be older than it is.
  2. The U-Th method is unreliable because it fails to account for nonradiogenic Th. This isotope would have been present in the source water producing the calcite deposits. As a result, Th would already be present in calcite at the time of formation. This nonradiogenic Th would make the samples appear to be older than they actually are.
  3. The 65,000-year-old dates for the three measurements from La Pasiega, Ardales, and Maltravieso are likely outliers. Just as I pointed out before, two of the research groups expressed concern that only 3 of the 53 measurements came in at 65,000 years in age. This discrepancy suggests that these dates are outliers, most likely reflecting the fact that the calcite deposits are an open system that formed with Th already present. Yet, the researchers from Spain and the UK who reported these results emphasized the few older dates while downplaying the younger dates.
  4. Multiple measurements on the same piece of art yielded discordant ages. For example, the researchers made five age-date measurements of the hand stencil at Maltravieso. These dates (66.7 kya [thousand years ago], 55.2 kya, 35.3 kya, 23.1 kys, and 14.7 kya) were all over the place. And yet, the researchers selected the oldest date for the age of the hand stencil, without justification.
  5. Some of the red “markings” on cave walls that were dated may not be art. Red markings are commonplace on cave walls and can be produced by microorganisms that secrete organic materials or iron oxide deposits. It is possible that some of the markings that were dated were not art at all.
  6. The method used by the researchers to sample the calcite deposits may have been flawed. One team expressed concern that the sampling technique may have unwittingly produced dates for the cave surface on which the paintings were made rather than the pigments used to make the art itself. If the researchers inadvertently dated the cave surface, it could easily be older than the art.

In light of these many shortcomings, it is questionable if the U-Th method to date cave art is reliable. After review, the call from the field is overturned. There is no conclusive evidence that Neanderthals made art.

Why Does This Matter?

Artistic expression reflects a capacity for symbolism. And many people view symbolism as a quality unique to human beings that contributes to our advanced cognitive abilities and exemplifies our exceptional nature. In fact, as a Christian, I see symbolism as a manifestation of the image of God. If Neanderthals possessed symbolic capabilities, such a quality would undermine human exceptionalism (and with it the biblical view of human nature), rendering human beings nothing more than another hominin. At this juncture, every claim for Neanderthal symbolism has failed to withstand scientific scrutiny.

Now, it is time for me to go back to the game.

Who dey! Who dey! Who dey think gonna beat dem Bengals!

Resources:

Endnotes

  1. L. Hoffmann et al., “U-Th Dating of Carbonate Crusts Reveals Neandertal Origin of Iberian Cave Art,” Science359 (February 23, 2018): 912–15, doi:10.1126/science.aap7778.
  2. W. G. Pike et al., “U-Series Dating of Paleolithic Art in 11 Caves in Spain,” Science 336 (June 15, 2012): 1409–13, doi:10.1126/science.1219957.
  3. Georges Sauvet et al., “Uranium-Thorium Dating Method and Palaeolithic Rock Art,” Quaternary International 432 (2017): 86–92, doi:10.1016/j.quaint.2015.03.053.
  4. Ludovic Slimak et al., “Comment on ‘U-Th Dating of Carbonate Crusts Reveals Neandertal Origin of Iberian Cave Art,’” Science 361 (September 21, 2018): eaau1371, doi:10.1126/science.aau1371; Maxime Aubert, Adam Brumm, and Jillian Huntley, “Early Dates for ‘Neanderthal Cave Art’ May Be Wrong,” Journal of Human Evolution (2018), doi:10.1016/j.jhevol.2018.08.004; David G. Pearce and Adelphine Bonneau, “Trouble on the Dating Scene,” Nature Ecology and Evolution 2 (June 2018): 925–26, doi:10.1038/s41559-018-0540-4.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/10/17/further-review-overturns-neanderthal-art-claim

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.

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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

The Endosymbiont Hypothesis: Things Aren’t What They Seem to Be

theendosymbionthypothesis

BY FAZALE RANA – AUGUST 29, 2018

Sometimes, things just aren’t what they seem to be. For example, when it comes to the world of biology:

  • Fireflies are not flies; they are beetles
  • Prairie dogs are not dogs; they are rodents
  • Horned toads are not toads; they are lizards
  • Douglas firs are not firs; they are pines
  • Silkworms are not worms; they are caterpillars
  • Peanuts are not nuts; they are legumes
  • Koala bears are not bears; they are marsupials
  • Guinea pigs are not from Guinea and they are not pigs; they are rodents from South America
  • Banana trees are not trees; they are herbs
  • Cucumbers are not vegetables; they are fruit
  • Mexican jumping beans are not beans; they are seeds with a larva inside

And . . . mitochondria are not alphaproteobacteria. In fact, evolutionary biologists don’t know what they are—at least, if recent work by researchers from Uppsala University in Sweden is to be taken seriously.1

As silly as this list may be, evolutionary biologists are not amused by this latest insight about the identity of mitochondria. Uncertainty about the evolutionary origin of mitochondria removes from the table one of the most compelling pieces of evidence for the endosymbiont hypothesis.

A cornerstone idea within the modern evolutionary framework, biology textbooks often present the endosymbiont hypothesis as a well-evidenced, well-established evolutionary explanation for the origin of complex cells (eukaryotic cells). Yet, confusion and uncertainty surround this idea, as this latest discovery attests. To put it another way: when it comes to the evolutionary explanation for the origin of complex cells in biology textbooks, things aren’t what they seem.

The Endosymbiont Hypothesis

Most evolutionary biologists believe that the endosymbiont hypothesis is the best explanation for one of the key transitions in life’s history—namely, the origin of complex cells from bacteria and archaea. Building on the ideas of Russian botanist Konstantin Mereschkowski, Lynn Margulis (1938–2011) advanced the endosymbiont hypothesis to explain the origin of eukaryotic cells in the 1960s.

Since that time, Margulis’s ideas on the origin of complex cells have become an integral part of the evolutionary paradigm. Many life scientists find the evidence for this hypothesis compelling; consequently, they view it as providing broad support for an evolutionary explanation for the history and design of life.

According to this hypothesis, complex cells originated when symbiotic relationships formed among single-celled microbes after free-living bacterial and/or archaeal cells were engulfed by a “host” microbe. (Ingested cells that take up permanent residence within other cells are referred to as endosymbionts.)

the-endosymbiont-hypothesis

The Evolution of Eukaryotic Cells According to the Endosymbiont Hypothesis

Image source: Wikipedia

Presumably, organelles such as mitochondria were once endosymbionts. Evolutionary biologists believe that once taken inside the host cell, the endosymbionts took up permanent residence, with the endosymbiont growing and dividing inside the host. Over time, endosymbionts and hosts became mutually interdependent, with the endosymbionts providing a metabolic benefit for the host cell. The endosymbionts gradually evolved into organelles through a process referred to as genome reduction. This reduction resulted when genes from endosymbionts’ genomes were transferred into the genome of the host organism. Eventually, the host cell evolved machinery to produce proteins needed by the former endosymbiont and processes to transport those proteins into the organelle’s interior.

Evidence for the Endosymbiont Hypothesis

The morphological similarity between organelles and bacteria serve as one line of evidence for the endosymbiont hypothesis. For example, mitochondria are about the same size and shape as a typical bacterium and they have a double membrane structure like the gram-negative cells. These organelles also divide in a way that is reminiscent of bacterial cells.

Biochemical evidence also seems to support the endosymbiont hypothesis. Evolutionary biologists view the presence of the diminutive mitochondrial genome as a vestige of this organelle’s evolutionary history. Additionally, biologists also take the biochemical similarities between mitochondrial and bacterial genomes as further evidence for the evolutionary origin of these organelles.

The presence of the unique lipid cardiolipin in the mitochondrial inner membrane also serves as evidence for the endosymbiont hypothesis. Cardiolipin is an important lipid component of bacterial inner membranes. Yet, it is not found in the membranes of eukaryotic cells—except for the inner membranes of mitochondria. In fact, biochemists consider it a signature lipid for mitochondria and a vestige of this organelle’s evolutionary history.

But, as compelling as these observations may be, for many evolutionary biologists phylogenetic analysis provides the most convincing evidence for the endosymbiont hypothesis. Evolutionary trees built from the DNA sequences of mitochondria, bacteria, and archaea place these organelles among a group of microbes called alphaproteobacteria. And, for many (but not all) evolutionary trees, mitochondria cluster with the bacteria, Rickettsiales.For evolutionary biologists, these results mean that the endosymbionts that eventually became the first mitochondria were alphaproteobacteria. If mitochondria were notevolutionarily derived from alphaproteobacteria, why would the DNA sequences of these organelles group with these bacteria in evolutionary trees?

But . . . Mitochondria Are Not Alphaproteobacteria

Even though evolutionary biologists seem certain about the phylogenetic positioning of mitochondria among the alphaproteobacteria, there has been an ongoing dispute as to the precise positioning of mitochondria in evolutionary trees, specifically whether or not mitochondria group with Rickettsiales. Looking to bring an end to this dispute, the Uppsula University research team developed a more comprehensive data set to build their evolutionary trees, with the hope that they could more precisely locate mitochondria among alphaproteobacteria. The researchers point out that the alphaproteobacterial genomes used to construct evolutionary trees stem from microbes found in clinical and agricultural settings, which is a small sampling of the alphaproteobacteria found in nature. Researchers knew this was a limitation, but, up to this point, this was the only DNA sequence data available to them.

To avoid the bias that arises from this limited data set, the researchers screened databases of DNA sequences collected from the Pacific and Atlantic Oceans for undiscovered alphaproteobacteria. They uncovered twelve new groups of alphaproteobacteria. In turn, they included these new genome sequences along with DNA sequences from previously known alphaproteobacterial genomes to build a new set of evolutionary trees. To their surprise, their analysis indicates that mitochondria are not alphaproteobacteria.

Instead, it looks like mitochondria belong to a side branch that separated from the evolutionary tree before alphaproteobacteria emerged. Adding to their surprise, the research team was unable to identify any bacterial species alive today that would group with mitochondria.

To put it another way: the latest study indicates that evolutionary biologists have no candidate for the evolutionary ancestor of mitochondria.

Does the Endosymbiont Hypothesis Successfully Account for the Origin of Mitochondria?

Evolutionary biologists suggest that there’s compelling evidence for the endosymbiont hypothesis. But when researchers attempt to delineate the details of this presumed evolutionary transition, such as the identity of the original endosymbiont, it becomes readily apparent that biologists lack a genuine explanation for the origin of mitochondria and, in a broader context, the origin of eukaryotic cells.

As I have written previously, the problems with the endosymbiont hypothesis are not limited to the identity of the evolutionary ancestor of mitochondria. They are far more pervasive, confounding each evolutionary step that life scientists envision to be part of the emergence of complex cells. (For more examples, see the Resources section.)

When it comes to the endosymbiont hypothesis, things are not what they seem to be. If mitochondria are not alphaproteobacteria, and if evolutionary biologists have no candidate for their evolutionary ancestor, could it be possible that they are the handiwork of the Creator?

Resources

Endnotes

  1. Joran Martijn et al., “Deep Mitochondrial Origin Outside the Sampled Alphaproteobacteria,” Nature 557 (May 3, 2018): 101–5, doi:10.1038/s41586-018-0059-5.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/08/29/the-endosymbiont-hypothesis-things-aren-t-what-they-seem-to-be

Evolution’s Flawed Approach to Science

evolutionsflawedapproach

BY FAZALE RANA – AUGUST 8, 2018

One of the things I find most troubling about the evolutionary paradigm is the view it fosters about the nature of biological systems—including human beings.

Evolution’s mechanisms, it is said, generate biological innovations by co-opting existing designs and cobbling them together to create new ones. As a result, many people in the scientific community regard biological systems as fundamentally flawed.

As biologist Ken Miller explains in an article for Technology Review:

“Evolution . . . does not produce perfection. The fact that every intermediate stage in the development of an organ must confer a selective advantage means that the simplest and most elegant design for an organ cannot always be produced by evolution. In fact, the hallmark of evolution is the modification of pre-existing structures. An evolved organism, in short, should show the tell-tale signs of this modification.1″

So, instead of regarding humans as “fearfully and wonderfully made” (as Scripture teaches), the evolutionary paradigm denigrates human beings, as a logical entailment of its mechanisms. It renders human beings as nothing more than creatures that have been cobbled together by evolutionary mechanisms.

Adding to this concern is the impact that the evolutionary paradigm has on scientific advance. Because many in the scientific community view biological systems as fundamentally flawed, they are predisposed to conclude—oftentimes, prematurely—that biological systems lack function or purpose when initial investigations into these systems fail to uncover any obvious rationale for why these systems are the way they are. And, once these investigators conclude that a biological system is flawed, the motivation to continue studying the system dissipates. Why try to understand a flawed design? Why focus attention on biological systems that lack function? Why invest research dollars studying systems that serve no purpose?

I would contend that viewing biological systems as the Creator’s handiwork provides a superior framework for promoting scientific advance, particularly when the rationale for the structure and function of a particular biological system is not apparent. If biological systems have been created, then there must be good reasons why these systems are structured and function the way they do. And this expectation drives further study of seemingly nonfunctional, purposeless systems with the full anticipation that their functional roles will eventually be uncovered.

Recent history validates the creation model approach. During the course of the last couple of decades, the scientific community has made discovery after discovery demonstrating (1) function for biological systems long thought to be useless evolutionary vestiges, or (2) an ingenious rationale for the architecture and operation of systems long regarded as flawed designs. (For examples, see the articles listed in the Resources section.)

These discoveries were made not because of the evolutionary paradigm but in spite of it.

So often, creationists and intelligent design proponents are accused of standing in the way of scientific advance. Skeptics of creation claim that if we conclude that God created biological systems, then science grinds to a halt. If God made it, then why continue to investigate the system in question?

But, I would assert that the opposite is true. The evolutionary paradigm stultifies science by viewing biological systems as flawed and vestigial. Yet, for the biological systems discussed in the articles listed in the Resources section, the view spawned by the evolutionary paradigm delayed important advances that could have been leveraged for biomedical purposes sooner, alleviating a lot of pain and suffering.

Because a creation model perspective regards designs in nature as part of God’s handiwork, it provides the motivation to keep pressing forward, seeking a rationale for systems that seemingly lack purpose. In the handful of instances in which the scientific community has adopted this mindset, it has been rewarded, paving the way for new scientific insight that leads to biomedical breakthroughs.

Resources

Endnotes

  1. Kenneth R. Miller, “Life’s Grand Design,” Technology Review 97 (February/March 1994): 24–32.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/08/08/evolution-s-flawed-approach-to-science

Do Plastic-Eating Bacteria Dump the Case for Creation?

doplasticeatingbacteria

BY FAZALE RANA – JULY 18, 2018

At the risk of stating the obvious: Plastics are an indispensable part of our modern world. Yet, plastic materials cause untold problems for the environment. One of the properties that makes plastics so useful also makes them harmful. Plastics don’t readily degrade.

Recently, researchers discovered a new strain of bacteria that had recently evolved the ability to degrade plastics. These microbes may help solve some of the environmental problems caused by plastics, but their evolution seemingly causes new problems for people who hold the view that a Creator is responsible for life’s origin and design. But, is this really the case? To find out, we need to break down this discovery.

One plastic in widespread use today is polyethylene terephthalate (PET). This polymer was patented in the 1940s and became widely used in the 1970s. Most people are familiar with PET because it is used to make drinking bottles.

This material is produced by reacting ethylene glycol with terephthalic acid (both produced from petroleum). Crystalline in nature, this plastic is a durable material that is difficult to break down, because of the inaccessibility of the ester linkages that form between the terephthalic acid and ethylene glycol subunits that make up the polymer backbone.

PET can be recycled, thereby mitigating its harmful effects on the environment. A significant portion of PET is mechanically recycled by converting it into fibers used to manufacture carpets.

In principle, PET could be recycled by chemically breaking the ester linkages holding the polymer together. When the ester linkages are cleaved, ethylene glycol and terephthalic acid are the breakdown products. These recovered starting materials could be reused to make more PET. Unfortunately, chemical recycling of PET is expensive and difficult to carry out because of the inaccessibility of the ester linkages. In fact, it is cheaper to produce PET from petroleum products than from the recycled monomers.

Can Bacteria Recycle PET?

An interesting advance took place in 2016 that has important implications for PET recycling. A team of Japanese researchers discovered a strain of the bacterium Ideonella sakaiensis that could break down PET into terephthalic acid and ethylene glycol.1 This strain was discovered by screening wastewater, soil, sediments, and sludge from a PET recycling facility. The microbe produces two enzymes, dubbed PETase and MHETase, that work in tandem to convert PET into its constituent monomers.

Evolution in Action

Researchers think that this microbe acquired DNA from the environment or another microbe via horizontal gene transfer. Presumably, this DNA fragment harbored the genes for cutinase, an enzyme that breaks down ester linkages. Once the I. sakaiensis strain picked up the DNA and incorporated it into its genome, the cutinase gene must have evolved so that it now encodes the information to produce two enzymes with the capacity to break down PET. Plus, this new capability must have evolved rather quickly, over the span of a few decades.

PETase Structure and Evolution

In an attempt to understand how PETase and MHETase evolved and how these two enzymes might be engineered for recycling and bioremediation purposes, a team of investigators from the University of Plymouth determined the structure of PETase with atomic level detail.2 They learned that this enzyme has the structural components characteristic of a family of enzymes called alpha/beta hydrolases. Based on the amino acid sequence of the PETase, the researchers concluded that its closest match to any existing enzyme is to a cutinase produced by the bacterium Thermobifida fusca. One of the most significant differences between these two enzymes is found at their active sites. (The active site is the location on the enzyme surface that binds the compounds that the enzyme chemically alters.) The active site of the PETase is broader than the T. fusca cutinase, allowing it to accommodate PET polymers.

As researchers sought to understand how PETase evolved from cutinase, they engineered amino acid changes in PETase, hoping to revert it to a cutinase. To their surprise, the resulting enzyme was even more effective at degrading PET than the PETase found in nature.

This insight does not help explain the evolutionary origin of PETase, but the serendipitous discovery does point the way to using engineered PETases for recycling and bioremediation. One could envision spraying this enzyme (or the bacterium I. sakaiensis) onto a landfill or in patches of plastics floating in the Earth’s oceans. Or alternatively using this enzyme at recycling facilities to generate the PET monomers.

As a Christian, I find this discovery exciting. Advances such as these will help us do a better job as planetary caretakers and as stewards of God’s creation, in accord with the mandate given to us in Genesis 1.

But, this discovery does raise a question: Does the evolution of a PET-eating bacterium prove that evolution is true? Does this discovery undermine the case for creation? After all, it is evolution happening right before our eyes.

Is Evolution in Action Evidence for Evolution?

To answer this question, we need to recognize that the term “evolution” can take on a variety of meanings. Each one reflects a different type of biological transformation (or presumed transformation).

It is true that organisms can change as their environment changes. This occurs through mutations to the genetic material. In rare circumstances, these mutations can create new biochemical and biological traits, such as the ones that produced the strain of I. sakaiensis that can degrade PET. If these new traits help the organism survive, it will reproduce more effectively than organisms lacking the trait. Over time, this new trait will take hold in the population, causing a transformation of the species.

And this is precisely what happened with I. sakaiensis. However, microbial evolution is not controversial. Most creationists and intelligent design proponents acknowledge evolution at this scale. In a sense, it is not surprising that single-celled microbes can evolve, given their extremely large population sizes and capacity to take up large pieces of DNA from their surroundings and incorporate it into their genomes.

Yet, I. sakaiensis is still I. sakaiensis. In fact, the similarity between PETase and cutinases indicates that only a few amino acid changes can explain the evolutionary origin of new enzymes. Along these lines, it is important to note that both cutinase and PETase cleave ester linkages. The difference between these two enzymes involves subtle structural differences triggered by altering a few amino acids. In other words, the evolution of a PET-degrading bacterium is easy to accomplish through a form of biochemical microevolution.

But just because microbes can undergo limited evolution at a biochemical level does not mean that evolutionary mechanisms can account for the origin of biochemical systems and the origin of life. That is an unwarranted leap. This study is evidence for microbial evolution, nothing more.

Though this advance can help us in our planetary stewardship role, this study does not provide the type of evidence needed to explain the origin of biochemistry and, hence, the origin of life through evolutionary means. Nor does it provide the type of evidence needed to explain the evolutionary origin of life’s major groups. Evolutionary biologists must develop appropriate evidence for these putative transformations, and so far, they haven’t.

Evidence of microbial evolution in action is not evidence for the evolutionary paradigm.

Resources:

Endnotes

  1. Shosuke Yoshida et al., “A Bacterium that Degrades and Assimilates Poly(ethylene terephthalate)” Science 351 (March 11, 2016): 1196–99, doi:10.1126/science.aad6359.
  2. Harry P. Austin, et al., “Characterization and Engineering of a Plastic-Degrading Aromatic Polyesterase,” Proceedings of the National Academy of Sciences, USA (April 17, 2018): preprint, doi:10.1073/pnas.1718804115.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/07/18/do-plastic-eating-bacteria-dump-the-case-for-creation

Sophisticated Cave Art Evinces the Image of God

sophisticatedcaveart

BY FAZALE RANA – MAY 23, 2018

It’s a new trend in art. Museums and galleries all over the world are exploring the use of sounds, smells, and lighting to enhance the viewer’s experience as they interact with pieces of art. The Tate Museum in London is one institution pioneering this innovative approach to experiencing artwork. For example, on display recently at Tate’s Sensorium was Irish artist Francis Bacon’s Figure in a Landscape, a piece that depicts a gray human figure on a bench. Visitors to the Sensorium put on headphones while they view this painting, and they hear sounds of a busy city. Added to the visual and auditory experiences are the bitter burnt smell of chocolate and the sweet aroma of oranges that engulf the viewer. This multisensory experience is meant to depict a lonely, brooding figure lost in the never-ending activities of a city, with the contrasting aromas simultaneously communicating the harshness and warmth of life in an urban setting.

It goes without saying that designing multisensory experiences like the ones on display at the Sensorium requires expertise in sound, taste, and lighting. This expertise makes recent discoveries on ancient cave and rock art found throughout the world all the more remarkable. As it turns out, the cave and rock art found in Europe, Asia, and Africa are multisensory displays.1 The sophistication of this early art highlights the ingenuity of the first artists—modern humans, who were people just like us.

Cave Art

Though many people have the perception that cave and rock art is crude and simplistic, in fact, it is remarkably sophisticated. For example, the Chauvet-Pont-d’Arc Cave in southern France houses cave art that dates (using carbon-14 measurements) to two periods: 28,000 to 31,000 years ago and 33,500 to 37,000 years ago. These cave sites house realistic depictions of hundreds of animals including herbivores such as horses, cattle, and mammoths. The art also depicts rhinos and carnivores such as cave lions, panthers, bears, and hyenas. The site also contains hand stencils and geometric shapes, such as lines and dots.

The Chauvet Cave human artists painted the animal figures on areas of the cave walls that they polished to make smooth and lighter in color. They also made incisions and etchings around the outline of the painted figures to create a three-dimensional quality to the art and to give the figures a sense of movement.

Multisensory Cave Art

One of the most intriguing aspects of cave art is its location in caves. Oftentimes, the animal figures are depicted deep within the cave’s interior, at unusual locations for the placement of cave paintings.

Recently, archaeologists have offered an explanation for the location of the cave art. It appears as if the artists made use of the caves’ acoustical properties to create a multisensory experience. To say it another way, the cave art is depicted in areas of the caves where the sounds in that area of the cave reinforce the cave paintings. For example, hoofed animals are often painted in areas of the caves where the echoes and reverberations make percussive sounds like those made by thundering hooves when these animals are running. Carnivores are often depicted in areas of the caves that are unusually quiet.

San Rock Art

Recently, researchers have discovered that the rock art produced by the San (indigenous hunter-gatherer people from Southern Africa), the oldest of which dates to about 70,000 years ago, also provides viewers a multisensory experience.2 Archaeologists believe that the art depicted on the rocks reflects the existence of a spirit world beneath the surface. These rock paintings are often created in areas where echoes can be heard, presumably reflecting the activities of the spirit world.

Who Made the Cave and Rock Art?

Clearly, the first human artists were sophisticated. But, when did this sophisticated behavior emerge? The discovery of art in Europe and Asia indicates that the first humans who made their way out of Africa as they migrated around the world carried with them the capacity for art. To put it another way, the capacity for art did not emerge in humans after they reached Europe, but instead was an intrinsic part of human nature before we began to make our way around the world.

The discovery of symbolic artifacts as old as 80,000 years in age in caves in South Africa(artistic expression is a manifestation of the capacity to represent the world with symbols) and the dating of the oldest San rock art at 70,000 years in age adds support to this view.

Linguist Shigeru Miyagawa points out that genetic evidence indicates that the San separated from the rest of humanity around 125,000 years ago. While the San remained in Africa, the group of humans who separated from the San and made their way into Asia and Europe came from a separate branch of humanity. And yet, the art produced by the San displays the same multisensory character as the art found in Europe and Asia. To say it another way, the rock art of the San and the cave art in Europe and Asia display unifying characteristics. These unifying features indicate that the art share the same point of origin. Given that the data seems to indicate that humanity’s origin is about 150,000 years ago, it appears that the origin of art coincides closely to the time that modern humans appear in the fossil record.3

Cave Art and Rock Evince the Biblical View of Human Nature

The sophistication of the earliest art highlights the exceptional nature of the first artists—modern humans, people just like you and me. The capacity to produce art reflects the capacity for symbolism—a quality that appears to be unique to human beings, a quality contributing to our advanced cognitive abilities, and a quality that contributes to our exceptional nature. As a Christian, I view symbolism (and artistic expression) as one of the facets of God’s image. And, as such, I would assert that the latest insights on cave art provide scientific credibility for the biblical view of human nature.

Resources

Endnotes

  1. Shigeru Miyagawa, Cora Lesure, and Vitor A. Nóbrega, “Cross-Modality Information Transfer: A Hypothesis about the Relationship among Prehistoric Cave Paintings, Symbolic Thinking, and the Emergence of Language,” Frontiers in Psychology 9 (February 20, 2018): 115, doi:10.3389/fpsyg.2018.00115.
  2. Francis Thackery, “Eland, Hunters and Concepts of ‘Symapthetic Control’: Expressed in Southern African Rock Art,’ Cambridge Archaeological Journal 15 (2005): 27–35, doi:10.1017/S0959774305000028.
  3. Miyagawa et al., “Cross-Modality Information Transfer,” 115.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/05/23/sophisticated-cave-art-evinces-the-image-of-god

Did Neanderthals Produce Cave Paintings?

didneanderthalsproducecavepaintings

BY FAZALE RANA – APRIL 25, 2018

One time when our kids were little, my wife and I discovered that someone had drawn a picture on one of the walls in our house. Though all of our children professed innocence, it was easy to figure out who the culprit was, because the little artist also wrote the first letter of her name on the wall next to her “masterpiece.”

If only archaeologists had it as easy as my wife and me when it comes to determining who made the ancient artwork on the cave walls in Europe. Most anthropologists think that modern humans produced the art. But, a growing minority of scientists think that Neanderthals were the artists, not modern humans. If anthropologists only had some initials to go by.

In the absence of a “smoking gun,” archaeologists believe they now have an approach that will help them determine the artists’ identity. Instead of searching for initials, researchers are trying to indirectly determine who the artists were by dating the cave art. They hope this approach will work because modern humans did not make their way into Europe until around 40,000 years ago. And Neanderthals disappeared around that same time. So, knowing the age of the art would help narrow down the artists’ identity.

Recently, a team from the UK and Spain have applied this new dating method to art found in the caves of Iberia (southwest corner of Europe). And based on the age of the art, they think that the paintings on the cave walls were produced by Neanderthals, not modern humans.1

Artistic expression reflects a capacity for symbolism. And many people view symbolism as a quality unique to human beings, contributing to our advanced cognitive abilities and reflecting our exceptional nature. In fact, as a Christian, I see symbolism as a manifestation of the image of God. Yet, if Neanderthals possessed symbolic capabilities, such a quality would undermine human exceptionalism (and with it the biblical view of human nature), rendering human beings nothing more than another hominin.

Limitations of Dating Cave Art

Dating cave art is challenging, to say the least. Typically, archaeologists will either: (1) date the remains associated with the cave art and try to establish a correlation, or (2) attempt to directly date the cave paintings using carbon-14 measurements of the pigments and charcoal used to make the art. Both approaches have limitations.

In 2012, researchers from the UK and Spain employed a new technique to date the art found on the walls in 11 caves located in northwest Spain.2 This dating method measures the age of the calcite deposits beneath the cave paintings and those that formed over the artwork, once the paintings had been created. As water flows down cave walls, it deposits calcite. When calcite forms it contains trace amounts of U-238. This isotope decays into Th-230. Normally, detection of such low quantities of these isotopes would require extremely large samples. The researchers discovered that by using accelerator mass spectrometry they could get by with 10-milligram samples.

By dating the calcite samples, they produced minimum and maximum ages for the cave paintings. While most of the 50 samples they took dated to around 25,000 years in age (or more recent than that), three were significantly older. They found a claviform-like symbol that dated to 31,000 years in age. They also found hand stencils that were 37,000 years old and, finally, a red disk that dated to 41,000 years in age.

Most anthropologists believe modern humans made their way into Europe around 40,000 years ago, prompting researchers to suggest that maybe Neanderthals created some of the cave art, “because of the 40.8 ky date for the disk is a minimum age, it cannot be ruled out that the earliest paintings were symbolic expressions of Neanderthals, which were present at Cantabrian Spain until at least 42 ka.”3

Dating the Art from Three Cave Sites in Iberia

Recently, this research team applied the same U-Th dating method to the art found in three cave sites in Iberia: (1) La Pasiega, which houses paintings of animals, linear signs, claviform signs, and dots; (2) Ardales, which contains about 1,000 paintings of animals, along with dots, discs, lines, geometric shapes, and hand stencils; and (3) Maltravieso, which displays a set of hand stencils and geometric designs.

The research team took a total of 53 samples from 25 carbonate formations associated with the cave art in these three cave sites. While most of the samples dated to 40,000 years old or less, three measurements produced minimum ages of around 65,000 years in age, including: (1) red scalariform from La Pasiega, (2) red areas from Ardales, and (3) a hand stencil from Maltravieso. On the basis of the three measurements, the team concluded that the art must have been made by Neanderthals because modern humans had not made their way into Iberia at that time. In other words, Neanderthals made art, just like modern humans did.

Are These Results Valid?

At first glance, it seems like the research team has a compelling case for Neanderthal art. Yet, careful examination of the U-Th method and the results raise some concerns.

First, it is not clear if the U-Th method yields reliable results. Recently, a team from France and the US questioned the application of the U-Th method to date cave art.4 Like all radiometric dating methods, the U-Th method only works if the system to be age-dated is closed. In other words, once the calcite deposit forms, the U-Th method will only yield reliable results if none of the U or Th moves in or out of the deposit. Unfortunately, it does not appear as if the calcite films are closed systems. The calcite films form as a result of hydrological activity in the cave. Once a calcite film forms, water will continue to flow over its surface, leeching out U (because U is much more water soluble than Th). This process will make it seem as if the calcite film and, hence, the underlying artwork is much older than it actually is.

In the face of this criticism, the team from the UK and Spain assert the reliability of their method because, for a few of the calcite deposits, they sampled the outermost surface, the middle of the deposit, and the innermost region. Measurements of these three samples gave ages that matched the expected chronology, with the innermost layer measuring older than the outermost surface. But, as the researchers from France and the US (who challenge the validity of the U-Th method to date cave art) point out, this sampling protocol doesn’t ensure that the calcite is a closed system.

Additionally, critics from France and the US identified several examples of cave art dated by both carbon-14 methods and U-Th methods, noting that the carbon-14 method consistently gives much younger ages than the U-Th method. This difference is readily explained if the calcite is an open system.

Secondly, it seems more plausible that the 65,000-year-old dates are outliers. It is important to note that of the 53 samples measured, only three gave age-dates of 65,000 years. The remaining samples gave dates much younger, typically around 40,000 years in age. Given the concerns about the calcite being an open system, should the 65,000-year-old samples be viewed as mere outliers?

Compounding this concern is the fact that samples taken from the same piece of art give discordant dates, with one of the samples dating to 65,000 years in age and the other two samples dating to be much younger. The team from the UK and Spain argue that the artwork was produced in a patchwork manner. But this explanation does not account for the observation that the artwork appears to be a unified piece.

What Does Neanderthal Biology Say?

The archaeological record is not the only evidence we have available to us to assess Neanderthals’ capacity for symbolism (and advanced cognitive abilities). Scientists can also glean insight from Neanderthal biology.

As I discuss in Who Was Adam?, comparisons of the genomes of Neanderthals and modern humans reveal important differences in a number of genes related to neural development, suggesting that there are cognitive differences between the two species. Additionally, the fossil remains of Neanderthals indicate that their brain development s took a different trajectory than ours after birth. As a result, it doesn’t appear as if Neanderthals experienced much of an adolescence (which is the time that significant brain development takes place in modern humans). Finally, the brain structure of Neanderthals indicates that these creatures lacked advanced cognitive capacity and the hand-eye coordination needed to make art.

On the basis of concerns about the validity of the U-Th method when applied to dating calcite films and Neanderthal brain biology, I remain unconvinced that Neanderthals made cave art, let alone had the capacity to do so. So, to me, it appears as if modern humans are, indeed, the “guilty party.” The entire body of evidence still indicates that they are the ones who painted the walls of caves throughout the world. Though, I doubt either my wife or I will have these early artists scrub down the cave walls as punishment. The cave art is much too precious.

Resources

Endnotes

  1. D. L. Hoffmann et al., “U-Th Dating of Carbonate Crusts Reveals Neanderthal Origin of Iberian Cave Art,” Science 359 (February 23, 2018): 912–15, doi:10.1126/science.aap7778.
  2. A. W. G. Pike et al., “U-Series Dating of Paleolithic Art in 11 Caves in Spain,” Science 336 (June 15, 2012): 1409–13, doi:10.1126/science.1219957.
  3. A. W. G. Pike et al., “U-Series Dating of Paleolithic Art.”
  4. Georges Sauvet et al., “Uranium-Thorium Dating Method and Paleolithic Rock Art,” Quaternary International432 (2017): 86–92, doi:10.1016/j.quaint.2015.03.053.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/04/25/did-neanderthals-produce-cave-paintings

Mitochondria’s Deviant Genetic Code: Evolution or Creation?

mitochondriasdeviantgeneticcode

BY FAZALE RANA – APRIL 18, 2018

When I was in high school, I had the well-deserved reputation of being a wise guy—though the people who knew me then might have preferred to call me a wise—, instead. Either way, for being a wise guy, I sure didn’t display much wisdom during my teenage years.

I would like to think that I am wiser today. But, the little wisdom I do possess didn’t come easy. To quote singer and songwriter, Helen Reddy, “It’s wisdom born of pain.”

Life’s hardships sure have a way of teaching you lessons. But, I also learned that there is a shortcut to gaining wisdom—if you are wise enough to recognize it. (See what I did there?) It is better to solicit the advice of wise people than to gain wisdom through life’s bitter experiences. And, perhaps there was no wiser person ever than Solomon. Thankfully, Solomon’s wisdom was captured in the book of Proverbs. Many of life’s difficulties can be sidestepped if we are willing to heed Solomon’s advice.

Solomon gained his wisdom through observation and careful reflection. But, his wisdom also came through divine inspiration, and according to Solomon, it was through wisdom that God created the world in which we live (Proverbs 8:22–31). And, it is out of this wisdom that the Holy Spirit inspired Solomon to offer the insights found in the Proverbs.

In Psalm 104, the Psalmist (presumably David) echoes the same idea as Solomon: God created our world through wisdom. The Psalmist writes:

How many are your works, Lord!

In wisdom you made them all;

Based on Proverbs 8 and Psalm 104, I would expect God’s wisdom to be manifested in the created order. The Creator’s fingerprints—so evident in nature—should not only reflect the work of intelligent agency but also display undeniable wisdom. In my view, that wisdom should be reflected in the elegance, cleverness, and ingenuity of the designs seen throughout nature. Designs that reflect an underlying purpose. And these features are exactly what we observe when we study the biological realm—as demonstrated by recent work on aquatic mammal body size conducted by investigators from Stanford University.1

Body Sizes of Aquatic Mammals

Though the majority of the world’s mammals live in terrestrial habitats, the most massive members of this group reside in Earth’s oceans. For evolutionary biologists, common wisdom has it that the larger size of aquatic mammals reflects fewer evolutionary constraints on their body size because they live in the ocean. After all, the ocean habitat is more expansive than those found on land, and aquatic animals don’t need to support their weight because they are buoyed by the ocean.

As it turns out, common wisdom is wrong in this case. Through the use of mathematical modeling (employing body mass data from about 3,800 living species of aquatic mammals and around 3,000 fossil species), the research team from Stanford learned that living in an aquatic setting imposes tight constraints on body size, much more so than when animals live on land. In fact, they discovered (all things being equal) that the optimal body mass for aquatic mammals is around 1,000 pounds. Interestingly, the body mass distributions for members of the order Sirenia (dugongs and manatees), and the clades Cetacea (whales and dolphins), and Pinnipeds (sea lions and seals) cluster near 1,000 pounds.

Scientists have learned that the optimal body mass of aquatic mammals displays an underlying biological rationale and logic. It reflects a trade-off between two opposing demands: heat retention and caloric intake. Because the water temperatures of the oceans are below mammals’ body temperatures, heat retention becomes a real problem. Mammals with smaller bodies can’t consume enough food to compensate for heat loss to the oceans, and they don’t have the mass to retain body heat. The way around this problem is to increase their body mass. Larger bodies do a much better job at retaining heat than do smaller bodies. But, the increase in body mass can’t go unchecked. Maintaining a large body requires calories. At some point, metabolic demands outpace the capacity for aquatic mammals to feed, so body mass has to be capped (near 1,000 pounds).

The researchers noted a few exceptions to this newly discovered “rule.” Baleen whales have a body mass that is much greater than 1,000 pounds. But, as the researchers noted, these creatures employ a unique feeding mechanism that allows them to consume calories needed to support their massive body sizes. Filter feeding is a more efficient way to consume calories than hunting prey. The other exception is creatures such as otters. The researchers believe that their small size reflects a lifestyle that exploits both aquatic and terrestrial habitats.

Argument for God’s Existence from Wisdom

The discovery that the body mass of aquatic mammals has been optimized is one more example of the many elegant designs found in biological systems—designs worthy to be called the Creator’s handiwork. However, from my perspective, this optimization also reflects the Creator’s sagacity as he designed mammals for the purpose of living in the earth’s oceans.

But, instead of relying on intuition alone to make a case for a Creator, I want to present a formal argument for God’s existence based on the wisdom of biology’s designs. To make this argument, I follow after philosopher Richard Swinburne’s case for God’s existence based on beauty. Swinburne argues, “If God creates a universe, as a good workman he will create a beautiful universe. On the other hand, if the universe came into existence without being created by God, there is no reason to suppose that it would be a beautiful universe.”2 In other words, the beauty in the world around us signifies the Divine.

In like manner, if God created the universe, including the biological realm, we should expect to see wisdom permeating the designs in nature. On the other hand, if the universe came into being without God’s involvement, then there is no reason to think that the designs in nature would display a cleverness and ingenuity that affords a purpose—a sagacity, if you will. In fact, evolutionary biologists are quick to assert that most biological designs are flawed in some way. They argue that there is no purpose that undergirds biological systems. Why? Because evolutionary processes do not produce biological systems from scratch, but from preexisting systems that are co-opted through a process dubbed exaptation (by the late evolutionary biologist Stephen Jay Gould), and then modified by natural selection to produce new designs.3 According to biologist Ken Miller:

“Evolution . . . does not produce perfection. The fact that every intermediate stage in the development of an organ must confer a selective advantage means that the simplest and most elegant design for an organ cannot always be produced by evolution. In fact, the hallmark of evolution is the modification of pre-existing structures. An evolved organism, in short, should show the tell-tale signs of this modification.”4

And yet we see designs in biology that are not just optimized, but characterized by elegance, cleverness, and ingenuity—wisdom.

Truly, God is a wise guy.

Resources

Endnotes

  1. William Gearty, Craig R. McClain, and Jonathan L. Payne, “Energetic Tradeoffs Control the Size Distribution of Aquatic Mammals,” Proceedings of the National Academy of Sciences USA (March 2018): doi:10.1073/pnas.1712629115.
  2. Richard Swinburne, The Existence of God, 2nd ed. (New York: Oxford University Press, 2004), 190–91.
  3. Stephen Jay Gould and Elizabeth S. Vrba, “Exaptation: A Missing Term in the Science of Form,” Paleobiology8 (January 1, 1982): 4–15, doi:10.1017/S0094837300004310.
  4. Kenneth R. Miller, “Life’s Grand Design,” Technology Review 97 (February/March 1994): 24–32.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/04/11/mitochondria-s-deviant-genetic-code-evolution-or-creation