Is SETI an Intelligent Design Research Program?

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By Fazale Rana – July 24, 2019

I have always felt at home on college and university campuses. Perhaps this is one reason I enjoy speaking at university venues. I also love any chance I get to interact with college students. They have inquisitive minds and they won’t hesitate to challenge ideas.

Skeptical Challenge

A few years ago I was invited to present a case for a Creator, using evidence from biochemistry, at Cal Poly San Luis Obispo. During the Q&A session, a skeptical student challenged my claims, insisting that intelligent design/creationism isn’t science. In leveling this charge, he was advocating scientism—the view that science is the only way to discover truth; in fact, science equates to truth. Thus, if something isn’t scientific, then it can’t be true. On this basis he rejected my claims.

You might be surprised by my response. I agreed with my questioner.

My case for a Creator based on the design of biochemical systems is not science. It is a philosophical and theological argument informed by scientific discovery. In other words, scientific discoveries have metaphysical implications. And, by identifying and articulating those implications, I built a case for God’s existence and role in the origin and design of life.

Having said this, I do think that design detection is legitimately part of the fabric of science. We can use scientific methodologies to detect the work of intelligent agency. That is, we can develop rigorous scientific evidence for intelligent design. I also think we can ascribe attributes to the intelligent designer from scientific evidence at hand.

In defense of this view, I (and others who are part of the Intelligent Design Movement, or IDM) have pointed out that there are branches of science that function as intelligent design programs, such as research in archaeology and the Search for Extraterrestrial Intelligence (SETI). We stand to learn much from these disciplines about the science of design detection. (For a detailed discussion, see the Resources section.)

SETI and Intelligent Design

Recently, I raised this point in a conversation with another skeptic. He challenged me on that point, noting that Seth Shostak, an astronomer from the SETI Institute, wrote a piece for Space.com repudiating the connection between intelligent design (ID) and SETI, arguing that they don’t equate.

 

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Figure: Seth Shostak. Image credit: Wikipedia

 

According to Shostak,

“They [intelligent design proponents] point to SETI and say, ‘upon receiving a complex radio signal from space, SETI researchers will claim it as proof that intelligent life resides in the neighborhood of a distant star. Thus, isn’t their search completely analogous to our own line of reasoning—a clear case of complexity implying intelligence and deliberate design?’ And SETI, they would note, enjoys widespread scientific acceptance.”1

Shostak goes on to say, “If we as SETI researchers admit this is so, it sounds as if we’re guilty of promoting a logical double standard. If the ID folks aren’t allowed to claim intelligent design when pointing to DNA, how can we hope to claim intelligent design on the basis of a complex radio signal?”2

In an attempt to distinguish the SETI Institute from the IDM, Shostak asserts that ID proponents make their case for intelligent design based on the complexity of biological and biochemical systems. But this is not what the SETI Institute does. According to Shostak, “The signals actually sought by today’s SETI searches are not complex, as the ID advocates assume. We’re not looking for intricately coded messages, mathematical series, or even the aliens’ version of ‘I Love Lucy.’”

Instead of employing complexity as an indicator of intelligent agency, SETI looks for signals that display the property of artificiality. What they mean by artificiality is that specifically, SETI is looking for a simple signal of narrow-band electromagnetic radiation that forms an endless sinusoidal pattern. According to SETI investigators, this type of signal does not occur naturally. Shostak also points out that the context of the signal is important. If the signal comes from a location in space that couldn’t conceivably harbor life, then SETI researchers would be less likely to conclude that it comes from an intelligent civilization. On the other hand, if the signal comes from a planetary system that appears life-friendly, this signal would be heralded as a successful detection event.

Artificiality and Intelligent Design

I agree with Shostak. Artificiality, not complexity, is the best indicator of intelligent design. And, it is also important to rule out natural process explanations. I can’t speak for all creationists and ID proponents, but the methodology I use to detect design in biological systems is precisely the same one the SETI Institute employs.

In my book The Cell’s Design, I propose the use of an ID pattern to detect design. Toward this end, I point out that objects, devices, and systems designed by human beings—intelligent designers—are characterized by certain properties that are distinct from objects and systems generated by natural processes. To put it in Shostak’s terms, human designs display artificiality. And we can use the ID pattern as a way to define what artificiality should look like.

Here are three ways I adopt this approach:

  1. In The Cell’s Design, I follow after natural theologian William Paley’s work. Paley described designs created by human beings as contrivances in which the concept of artificiality was embedded. I explain examples of such artificiality in biochemical systems.
  2. In Origins of Life (a work I coauthored with astronomer Hugh Ross) and Creating Life in the Lab, I point out that natural processes don’t seem to be able to account for the origin of life and, hence, the origin of biochemical systems.
  3. Finally, in Creating Life in the Lab, I show that attempts to create protocells starting with simple molecules and attempts to recapitulate the different stages in the origin-of-life pathway depend upon intelligent agency. This dependence further reinforces the artificiality displayed by biochemical systems.

Collectively, all three books present a comprehensive case for a Creator’s role in the origin and fundamental design of life, with each component of the overall case for design resting on the artificiality of biochemical systems. So, even though the SETI Institute may want to distance themselves from the IDM, SETI is an intelligent design program. And intelligent design is, indeed, part of the construct of science.

In other words, scientists from a creation model perspective can make a rigorous scientific case for the role of intelligent agency in the origin and design of biochemical systems, and even assign attributes to the designer. At that point, we can then draw metaphysical conclusions about who that designer might be.

Resources

Endnotes
  1. Seth Shostak, “SETI and Intelligent Design,” Space.com (December 1, 2005), https://www.space.com/1826-seti-intelligent-design.html.
  2. Shostak, “SETI and Intelligent Design.”

Reprinted with permission by the author

Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/11/21/vocal-signals-smile-on-the-case-for-human-exceptionalism

Does Old-Earth Creationism Make God Deceptive?

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By Fazale Rana – July 17, 2019

“Are [vestigial structures] unequivocal evidence of evolution?

No. Are they reasonable evidence of evolution? Yes.

Ditto gene sequences.

Appearance of evolution is no more a valid deflection [for the overwhelming evidence for evolution] than the appearance of age is a valid dodge of the overwhelming confluence of evidence of antiquity.

Both are sinking ships. I got off before going under with you on this one.”

—Hill R. (a former old-earth creationist who now espouses theistic evolution/evolutionary creationism)

Most people who follow my work at Reasons to Believe know I question the grand claim of the evolutionary paradigm; namely, that evolutionary processes provide the exclusive explanation for the origin, design, and history of life. In light of my skepticism, friends and foes alike often ask me how I deal with (what many people perceive to be) the compelling evidence for the evolutionary history of life, such as vestigial structures and shared genetic features in genomes.

As part of my response, I point out that this type of evidence for evolution can be accommodated by a creation model, with the shared features reflecting common design, not common descent—particularly now that we know that there is a biological rationale for many vestigial structures and shared genetic features. This response prompted my friend Hill R. to level his objection. In effect, Hill says I am committing the “appearance of evolution” fallacy, which he believes is analogous to the “appearance of age” fallacy committed by young-earth creationists (YECs).

Hill is not alone in his criticism. Other people who embrace theistic evolution/evolutionary creation (such as my friends at BioLogos) level a similar charge. According to these critics, both appearance of age and appearance of evolution fallacies make God deceptive.

If biological systems are designed, but God made them appear as if they evolved, then the conclusions we draw when we investigate nature are inherently untrustworthy. This is a problem because, according to Scripture, God reveals himself to us through the record of nature. But if we are misled by nature’s features and, consequently, draw the wrong conclusion, then it makes God deceptive. However, God cannot lie or deceive. It is contrary to his nature.

So, how do I respond to this theological objection to RTB’s creation model?

Before I reply, I want to offer a little more background information to make sure that anyone who is unfamiliar with this concern can better appreciate the seriousness of the charge against our creation model. If you don’t need the background explanation, then feel free to skip ahead to A Response to the Appearance of Evolution Challenge.

Evidence for Evolution: Vestigial Structures

Evolutionary biologists often point to vestigial structures—such as the pelvis and hind limbs of whales and dolphins (cetaceans)—as compelling evidence for biological evolution. Evolutionary biologists view vestigial structures this way because they are also homologous (structurally similar) structures. Vestigial structures are rudimentary body parts that are smaller and simpler than the corresponding features possessed by the other members of a biological group. As a case in point, the whale pelvis and hind limbs are homologous to the pelvis and hind limbs of all other mammals.

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Figure 1: Whale Pelvis. Image credit: Shutterstock

Evolutionary biologists believe that vestigial structures were fully functional at one time but degenerated over the course of many generations because the organisms no longer needed them to survive in an ever-changing environment—for example, when the whale ancestor transitioned from land to water. From an evolutionary standpoint, fully functional versions of these structures existed in the ancestral species. The structures’ form and function may be retained (possibly modified) in some of the evolutionary lineages derived from the ancestral species, but if no longer required, the structures become diminished (and even lost) in other lineages.

Evidence for Evolution: Shared Genetic Features

Evolutionary biologists also consider shared genetic features found in organisms that naturally group together as compelling evidence for common descent. One feature of particular interest is the identical (or nearly identical) DNA sequence patterns found in genomes. According to this line of reasoning, the shared patterns arose as a result of a series of substitution mutations that occurred in the common ancestor’s genome. Presumably, as the varying evolutionary lineages diverged from the nexus point, they carried with them the altered sequences created by the primordial mutations.

Synonymous mutations play a significant role in this particular argument for common descent. Because synonymous mutations don’t alter the amino acid sequence of proteins, their effects are considered to be inconsequential. (In a sense, they are analogous to vestigial anatomical features.) So, when the same (or nearly the same) patterns of synonymous mutations are observed in genomes of organisms that cluster together into the same group, most life scientists interpret them as compelling evidence of the organisms’ common evolutionary history.

A Response to the Evidence for Evolution

As a rejoinder to this evidence, I point out that we continue to uncover evidence that vestigial structures display function (see Vestigial Structures are Functional in the Resources section.) Likewise, evidence is beginning to accumulate that synonymous mutations have functional consequences. (see Shared Genetic Features Reflect Design in the Resources section.) Again, if these features have functional utility, then they can reasonably be interpreted as the Creator’s handiwork.

But, even though these biological features bear function, many critics of the RTB model think that the shared features of these biological systems still bear the hallmarks of an evolutionary history. Therefore, they argue that these features look as if they evolved. And if so, we are guilty of the “appearance of evolution” fallacy.

Appearance of Age and the Appearance of Evolution

In 1857, Philip Gosse, a biologist and preacher from England, sought to reconcile the emerging evidence for Earth’s antiquity with Scripture. Gosse was convinced that the earth was old. He was also convinced that Scripture taught that the earth was young. In an attempt to harmonize these disparate stances, he proposed the appearance of age argument in a book titled Omphalos. In this work, Gosse argued that God created Earth in six days, but made it with the appearance of age.

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Figure 2: Philip Henry Gosse, 1855. Image credit: Wikipedia

This idea persists today, finding its way into responses modern-day YECs make to the scientific evidence for Earth’s and life’s antiquity. For many people (including me), the appearance of age argument is fraught with theological problems, the chief one being that it makes God deceptive. If Earth appears to be old, and it measures to be old, yet it is young, then we can’t trust anything we learn when we study nature. This problem is not merely epistemological; it is theological because nature is one way that God has chosen to make himself known to us. But if our investigation of nature is unreliable, then it means that God is untrustworthy.

In other words, on the surface, both the appearance of age and the appearance of evolution arguments made by YECs and old-earth creationists (OECs), respectively, seem to be equally problematic.

But does the RTB position actually commit the appearance of evolution fallacy? Does it suffer from the same theological problems as the argument first presented by Gosse in Omphalos? Are we being hypocritical when we criticize the appearance of age fallacy, only to commit the appearance of evolution fallacy?

A Response to the Appearance of Evolution Challenge

This charge against the RTB creation model neglects to fully represent the reasons I question the evolutionary paradigm.

First, my skepticism is not theologically motivated but scientifically informed. For example, I point out in an article I recently wrote for Sapientia that a survey of the scientific literature makes it clear that evolutionary theory as currently formulated cannot account for the key transitions in life’s history, including:

  • the origin of life
  • the origin of eukaryotic cells
  • the origin of body plans
  • the origin of human exceptionalism

Additionally, some predictions that flow out of the evolutionary paradigm have failed (such as the widespread prevalence of convergence), further justifying my skepticism. (See Scientific Challenges to the Evolutionary Paradigm in the Resources section.)

In other words, when we interpret shared features as a manifestation of common design (including vestigial structures and shared genetic patterns), it is in the context of scientifically demonstrable limitations of the evolutionary framework to fully account for life’s origin, history, and design. To put it differently, because of the shortcomings of evolutionary theory, we don’t see biological systems as having evolved. Rather, we think they’ve been designed.

Appearance of Design Fallacy

Even biologists who are outspoken atheists readily admit that biological and biochemical systems appear to be designed. Why else would Nobel Laureate Francis Crick offer this word of caution to scientists studying biochemical systems: “Biologists must keep in mind that what they see was not designed, but rather evolved.”1 What other reason would evolutionary biologist Richard Dawkins offer for defining biology as “the study of complicated things that give the appearance of having been designed for a purpose”?2

Biologists can’t escape the use of design language when they describe the architecture and operation of biological systems. In and of itself, this practice highlights the fact that biological systems appear to be designed, not evolved.

To sidestep the inexorable theological implications that arise when biologists use design language, biologist Colin Pittendrigh coined the term teleonomy in 1958 to describe systems that appear to be purposeful and goal-directed, but aren’t. In contrast with teleology—which interprets purposefulness and goal-directedness as emanating from a Mind— teleonomy views design as the outworking of evolutionary processes. In other words, teleonomy allows biologists to utilize design language— when they describe biological systems—without even a tinge of guilt.

In fact, the teleonomic interpretation of biological design resides at the heart of the Darwinian revolution. Charles Darwin claimed that natural selection could account for the design of biological systems. In doing so, he supplanted Mind with mechanism. He replaced teleology with teleonomy.

Prior to Darwin, biology found its grounding in teleology. In fact, Sir Richard Owen—one of England’s premier biologists in the early 1800s—produced a sophisticated theoretical framework to account for shared biological features found in organisms that naturally cluster together (homologous structures). For Owen (and many biologists of his time) homologous structures were physical manifestations of an archetypal design that existed in the Creator’s mind.

Thus, shared biological features—whether anatomical, physiological, biochemical, or genetic—can be properly viewed as evidence for common design, not common descent. In fact, when Darwin proposed his theory of evolution, he appropriated Owen’s concept of the archetype but then replaced it with a hypothetical common ancestor.

Interestingly, Owen (and other like-minded biologists) found an explanation for vestigial structures like the pelvis and hind limb bones (found in whales and snakes) in the concept of the archetype. They regarded these structures as necessary to the architectural design of the organism. In short, a model that interprets shared biological characteristics from a design/creation model framework has historical precedence and is based on the obvious design displayed by biological systems.

Given the historical precedence for interpreting the appearance of design in biology as bona fide design and the inescapable use of design language by biologists, it seems to me that RTB’s critics commit the appearance of design fallacy when they (along with other biologists) claim that things in biology look designed, but they actually evolved.

Theories Are Underdetermined by Data

A final point. One of the frustrating aspects of scientific discovery relates to what’s called the underdetermination thesis.3 Namely, two competing theories can explain the same set of data. According to this idea, theories are underdetermined by data. This limitation means that two or more theories—that may be radically different from one another—can equally account for the same data. Or, to put it another way, the methodology of science never leads to one unique theory. Because of this shortcoming, other factors—nonscientific ones—influence the acceptance or rejection of a scientific theory, such as a commitment to mechanistic explanations to explain all of biology.

As a consequence of the underdetermination theory, evolutionary models don’t have the market cornered when it comes to offering an interpretation of biological data. Creation models, such as the RTB model—which relies on the concept of common design—also makes sense of the biological data. And given the inability of current evolutionary theory to explain key transitions in life’s history, maybe a creation model approach is the better alternative.

In other words, when we interpret vestigial structures and shared genetic features from a creation model perspective, we are not committing an appearance of age type of fallacy, nor are we making God deceptive. Instead, we are offering a common sense and scientifically robust interpretation of the elegant designs so prevalent throughout the living realm.

Far from a sinking ship one should abandon, a creation model offers a lifeline to scientific and biblical integrity.

Resources

Vestigial Structures Are Functional

Shared Genetic Features Reflect Design

Scientific Challenges for the Evolutionary Paradigm

Archetype Biology

Endnotes
  1. Francis Crick, What Mad Pursuit: A Personal View of Scientific Discovery (New York: Basic Books, 1988), 138.
  2. Richard Dawkins, The Blind Watchmaker: Why the Evidence for Evolution Reveals a Universe without Design (New York: W. W. Norton, 1996), 4.
  3. Val Dusek, Philosophy of Technology: An Introduction (Malden, MA: Blackwell Publishing, 2006), 12.

Reprinted with permission by the author

Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/11/21/vocal-signals-smile-on-the-case-for-human-exceptionalism

Membrane Biochemistry Challenges Route to Evolutionary Origin of Complex Cells

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By Fazale Rana – July 10, 2019

Unfortunately, the same thing could be said to biologists trying to discover the evolutionary route that led to the emergence of complex, eukaryotic cells. No matter the starting point, it seems as if you just can’t get there from here.

This frustration becomes most evident as evolutionary biologists try to account for the biochemical makeup of the membranes found in eukaryotic cells. In my opinion, this struggle is not just an inconvenient detour. As the following paragraphs show, obstacles line the roadway, ultimately leading to a dead end that exposes the shortcomings of the endosymbiont hypothesis—a cornerstone idea in evolutionary biology.

Endosymbiont Hypothesis

Most biologists believe that the endosymbiont hypothesis stands as the best explanation for the origin of complex cells. 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.

The mitochondrion represents the “poster child” of the endosymbiont hypothesis. Presumably, this organelle started as an endosymbiont. Evolutionary biologists believe that once engulfed by the host cell, the microbe took up permanent residency, growing and dividing inside the host. Over time, the endosymbiont and host became mutually interdependent, with the endosymbiont providing a metabolic benefit—such as a source of ATP—for the host cell. In turn, the host cell provided nutrients to the endosymbiont. Presumably, the endosymbiont gradually evolved into an organelle through a process referred to as genome reduction. This reduction resulted when genes from the endosymbiont’s genome were transferred into the genome of the host organism.

Evidence for the Endosymbiont Hypothesis
1. Most of the evidence for the endosymbiont hypothesis centers around mitochondria and their similarity to bacteria. Mitochondria are about the same size and shape as a typical bacterium and have a double membrane structure like gram-negative cells. These organelles also divide in a way that is reminiscent of bacterial cells.

2. Biochemical evidence also exists for the endosymbiont hypothesis. Evolutionary biologists view the presence of the diminutive mitochondrial genome as a vestige of this organelle’s evolutionary history. They see the biochemical similarities between mitochondrial and bacterial genomes as further evidence for the evolutionary origin of these organelles.

3. The presence of the unique lipid, cardiolipin, in the mitochondrial inner membrane also serves as evidence for the endosymbiont hypothesis. This important lipid component of bacterial inner membranes 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 the organelle’s evolutionary history. So far, the evolutionary route looks well-paved and clear.

Discovery of Lokiarchaeota

Evolutionary biologists have also developed other lines of evidence in support of the endosymbiont hypothesis. For example, biochemists have discovered that the genetic core (DNA replication and the transcription and translation of genetic information) of eukaryotic cells resembles that of the archaea. This similarity suggests to many biologists that a microbe belonging to the archaeal domain served as the host cell that gave rise to eukaryotic cells.

Life scientists think they may have determined the identity of that archaeal host. In 2015, a large international team of collaborators reported the discovery of Lokiarchaeota, a new phylum belonging to the archaea. This phylum clusters with eukaryotes on the evolutionary tree. Analysis of the genomes of Lokiarchaeota identifies a number of genes involved in membrane-related activities, suggesting that this microbe may well have possessed the ability to engulf other microbes.1 At this point, it looks like “you can get there from here.”

Challenges to the Endosymbiont Hypothesis

Despite this seemingly compelling evidence, the evolutionary route to the first eukaryotic cells is littered with potholes. I have written several articles detailing some of the obstacles. (See Challenges to the Endosymbiont Hypothesis in the Resources section.) Also, a divide on the evolutionary roadway called the lipid divide compounds the problem for the endosymbiont hypothesis.

Lipid Divide

The lipid divide refers to the difference in the chemical composition of the cell membranes found in bacteria and archaea. Phospholipids comprise the cell membranes of both sorts of microbes. But the similarity ends there. The chemical makeup of the phospholipids is distinct in bacteria and archaea.

Bacterial phospholipids are built around a d-glycerol backbone, which has a phosphate moiety bound to the glycerol in the sn-3 position. Two fatty acids are bound to the d-glycerol backbone at the sn-1 and sn-2 positions. In water, these phospholipids assemble into bilayer structures.

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Figure: Difference between archaeal (top) and bacterial (middle and bottom) phospholipids. Features include 1: isoprene chains, 2: ether linkage, 3: l-glycerol, 4 and 8: phosphate group, 5: fatty acid chains, 6: ester linkages, 7: d-glycerol, 9: lipid bilayer of bacterial membranes, 10: lipid monolayer found in some archaea. Image credit: Wikipedia

Archaeal phospholipids are constructed around an l-glycerol backbone (which produces membrane lipids with different stereochemistry than bacterial phospholipids). The phosphate moiety is attached to the sn-1 position of glycerol. Two isoprene chains are bound to the sn-2 and sn-3 positions of l-glycerol via ether linkages. Some archaeal membranes are formed from phospholipid bilayers, while others are formed from phospholipid monolayers.

Presumably, the structural features of the archaeal phospholipids serve as an adaptation that renders them ideally suited to form stable membranes in the physically and chemically harsh environments in which many archaea find themselves.

Lipid Divide Frustrates the Origin of Eukaryotic Cell Membranes

In light of the lipid divide and the evidence that seemingly indicates that the endosymbiotic host cell likely belonged to Lokiarchaeota, it logically follows that the membrane composition of eukaryotic cells should be archaeal-like. But, this expectation is not met and the evolutionary route encounters another pothole. Instead, the cell membranes of eukaryotic cells closely resemble bacterial membranes.

One way to repair the roadway is to posit that during the evolutionary process that led to the emergence of eukaryotic cells, a transition from archaeal-like membranes to bacterial-like membranes took place. In fact, supporting evidence comes from laboratory studies demonstrating that stable bilayers can form from a mixture of bacterial and archaeal phospholipids, even though the lipids from the two sources have opposite stereochemistry.

Evolutionary biologists Purificación López-García and David Moreira question if evidence can be marshaled in support of this scenario for two reasons.2 First, mixing of phospholipids in the lab is a poor model for cell membranes that function as a “dynamic cell-environment interface.”3

Second, they question if this transition is feasible given how exquisitely optimized membrane proteins must be to fit into cell membranes. The nature of protein optimization is radically different for bacterial and archaeal membranes. Because cell membrane systems are optimized, the researchers question if an adequate driving force for this transition exists.

In other words, these two scientists express serious doubts about the biochemical viability of a transitional stage between archaeal membranes. In light of these obstacles, López-García and Moreira write, “The archaea-to-bacteria membrane shift remains the Achilles’ heel for these models [that propose an archaeal host for endosymbionts].”4

In other words, you can’t get there from here.

Can Lokiarchaeota Traverse the Lipid Divide?

In the midst of this uncertain evolutionary route, a recent study by investigators from the Netherlands seems to point the way toward the evolutionary origin of eukaryotic membranes.5 Researchers screened the Lokiarchaeota genome for enzymes that would take part in phospholipid synthesis with the hope of finding clues about how this transition may have occurred. They conclude that this group of microbes could not make l-glycerol-1-phosphate (a key metabolic intermediate in the production of archaeal phospholipids) because it lacked the enzyme glycerol-1-phosphate dehydrogenase (G1PDH). They also discovered evidence that suggests that this group of microbes could make fatty acids and chemically attach them to sugars. The researchers argue that Lokiarchaeota could make some type of hybrid phospholipid with features of both archaeal and bacterial phospholipids.

The team’s approach to understanding how evolutionary processes could bridge the lipid divide and account for the origin of eukaryotic membranes is clever and inventive, to be sure. But it is far from convincing for at least four reasons.

1. Absence of evidence is not evidence of absence, as the old saying goes. Just because the research team didn’t find the gene for G1PDH in the Lokiarchaeota genetic material doesn’t mean this microbe didn’t have the capacity to make archaeal-type phospholipids. Toward this end, it is important to note that researchers have not cultured any microbe that belongs to this group organisms. The group’s existence is inferred from metagenomic analysis, which involves isolating small fragments of DNA from the environment (in this case a hydrothermal vent system in the Atlantic Ocean, called Loki’s Castle) and stitching them together into a genome. The Lokiarchaeota “genome” is low quality (1.4-fold coverage) and incomplete (8 percent of the genome is missing). Around one-third (32 percent) of the genome codes for proteins with unknown function. Could it be that an enzyme capable of generating l-glycerol-1-phosphate exists in the mysterious third of the genome? Or in the missing 8 percent?

2. While the researchers discovered that genes could conceivably work together to make d-glycerol-3-phosphate (though the enzymes encoded by these genes perform different metabolic functions), they found no direct evidence that Lokiarchaeota produces d-glycerol-3-phosphate. Nor did they find evidence for glycerol-3-phosphate dehydrogenase (G3PDH) in the Lokiarchaeota genetic material. This enzyme plays a key role in the synthesis of phospholipids in bacteria.

3. Though the researchers found evidence that Lokiarchaeota had the capacity to make fatty acids, some of the genes required for the process seem to have been acquired by these microbes via horizontal gene transfer with genetic material from bacteria. (It should be noted that 29 percent of the Lokiarchaeota genome comes from the bacteria.) It is not clear when Lokiarchaeota acquired these genes and, therefore, if this metabolic capability has any bearing on the origin of eukaryotes.

4. The researchers present no evidence that Lokiarchaeota possessed the protein machinery that would chemically attach isoprenoid lipids to d-glycerol-3-phosphate via ether linkages.

Thus, the only way to establish Lokiarchaeota membranes as a transitional evolutionary pathway between those found in Archaea and Bacteria is to perform chemical analysis of its membranes. At this juncture, such analysis is impossible to perform because no one has been able to culture Lokiarchaeota. In fact, other evidence suggests that this group of microbes possessed archaeal-type membranes. Researchers have recovered archaeal lipids in the sediments surrounding Loki’s Castle, but they have not recovered bacterial-like lipids.

More Lipid Divide Frustration

Given these problems, could it be that the host microbe for the endosymbiont was a member of Bacteria, not Archaea? While this model would solve the problem of the lipid divide, it leaves unexplained the similarity between the genetic core of eukaryotes and the Archaea. Nor does it account for the grouping of eukaryotes with the Archaea.

It doesn’t look like you can get there from here, either.

Evolutionary biologists Jonathan Lombard, Purificación López-García and David Moreira sum things up when they write, “The origin of eukaryotic membranes is a problem that is rarely addressed by the different hypotheses that have been proposed to explain the emergence of eukaryotes.”6 Yet, until this problem is adequately addressed, the evolutionary route to eukaryotes will remain obscure and the endosymbiont hypothesis noncompelling.

In light of this challenge and others, maybe a better way to make sense of the origin of eukaryotic cells is to view them as the Creator’s handiwork. For many scientists, it is a road less traveled, but it accounts for all of the data. You can get there from here.

Resources

Challenges to the Endosymbiont Hypothesis

Support for a Creation Model for the Origin of Eukaryotic Cells

Endnotes
  1. Anja Spang et al., “Complex Archaea that Bridge the Gap between Prokaryotes and Eukaryotes,” Nature 521 (May 14, 2015): 173–79, doi:10.1038/nature14447; Katarzyna Zaremba-Niedzwiedzka et al., “Asgard Archaea Illuminate the Origin of Eukaryotic Cellular Complexity,” Nature 541 (January 19, 2017): 353–58, doi:10.1038/nature21031.
  2. Purificación López-García and David Moreira, “Open Questions on the Origin of Eukaryotes,” Trends in Ecology and Evolution 30, no. 11 (November 2015): 697–708, doi:10.1016/j.tree.2015.09.005.
  3. López-García and Moreira, “Open Questions.”
  4. López-García and Moreira, “Open Questions.”
  5. Laura Villanueva, Stefan Schouten, and Jaap S. Sinninghe Damsté, “Phylogenomic Analysis of Lipid Biosynthetic Genes of Archaea Shed Light on the ‘Lipid Divide,’” Environmental Microbiology 19, no. 1 (January 2017): 54–69, doi:10.1111/1462-2920.13361.
  6. Jonathan Lombard, Purificación López-García, and David Moreira, “The Early Evolution of Lipid Membranes and the Three Domains of Life,” Nature Reviews Microbiology 10 (June 11, 2012): 507–15, doi:10.1038/nrmicro2815.

Reprinted with permission by the author

Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/11/21/vocal-signals-smile-on-the-case-for-human-exceptionalism