Tag: microfossils

Soft Tissue Preservation Mechanism Stabilizes the Case for Earth’s Antiquity

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BY FAZALE RANA – DECEMBER 19, 2018

One of the highlights of the year at Reasons to Believe (well, it’s a highlight for some of us, anyway) is the white elephant gift exchange at our staff Christmas party. It is great fun to laugh together as a staff as we take turns unwrapping gifts—some cheesy, some useless, and others highly prized—and then “stealing” from one another those two or three gifts that everyone seems to want.

Over the years, I have learned a few lessons about choosing a white elephant gift to unwrap. Avoid large gifts. If the gift is a dud, large items are more difficult to find a use for than small ones. Also, more often than not, the most beautifully wrapped gifts turn out to be the biggest letdowns of all.

Giving and receiving gifts isn’t just limited to Christmas. People exchange all types of gifts with one another for all sorts of reasons.

Gifting is even part of the scientific enterprise—with the gifts taking on the form of scientific discoveries and advances. Many times, discoveries lead to new beneficial insights and technologies—gifts for humanity. Other times, these breakthroughs are gifts for scientists, signaling a new way to approach a scientific problem or opening up new vistas of investigation.

Soft Tissue Remnants Preserved in Fossils

One such gift was given to the scientific community over a decade ago by Mary Schweitzer, a paleontologist at North Carolina State University. Schweitzer and her team of collaborators recovered flexible, hollow, and transparent blood vessels from the remains of a T. rex specimen after removing the mineral component of the fossil.1 These blood vessels harbored microstructures with a cell-like morphology (form and structure) that she and her collaborators interpreted to be the remnants of red blood cells. This work showed conclusively that soft tissue materials could be preserved in fossil remains.

Though unexpected, the discovery was a landmark achievement for paleontology. Since Schweitzer’s discovery, paleontologists have unearthed the remnants of all sorts of soft tissue materials from fossils representing a wide range of organisms. (For a catalog of some of these finds, see my book Dinosaur Blood and the Age of the Earth.)

With access to soft tissue materials in fossils, paleontologists have a new window into the biology of Earth’s ancient life.

The Scientific Case for a Young Earth

Some Christians also saw Schweitzer’s discovery as a gift. But for them the value of this scientific present wasn’t the insight it provides about past life on Earth. Instead, they viewed this discovery (and others like it) as evidence that the earth must be no more than a few thousand years old. From a young-earth creationist (YEC) perspective, the survival of soft tissue materials in fossils indicates that these remains can’t be millions of years old. As a case in point, at the time Schweitzer reported her findings, John Morris, a young-earth proponent from the Institute for Creation Research, wrote:

Indeed, it is hard to imagine how soft tissue could have lasted even 5,000 years or so since the Flood of Noah’s day when creationists propose the dinosaur was buried. Such a thing could hardly happen today, for soft tissue decays rather quickly under any condition.2

In other words, from a YEC perspective, it is impossible for fossils to contain soft tissue remnants and be millions of years old. Soft tissues shouldn’t survive that long; they should readily degrade in a few thousand years. From a YEC view, soft tissue discoveries challenge the reliability of radiometric dating methods used to determine the fossils’ ages and, consequently, Earth’s antiquity. Furthermore, these breakthrough discoveries provide compelling scientific evidence for a young earth and support the idea that the fossil record results from a recent global (worldwide) flood.

Admittedly, on the surface the argument carries some weight. At first glance, it is hard to envision how soft tissue materials could survive for vast periods of time, given the wide range of mechanisms that drive the degradation of biological materials.

Preservation of Soft Tissues in Fossil Remains

Despite this first impression, over the last decade or so paleontologists have identified a number of mechanisms that can delay the degradation of soft tissues long enough for them to become entombed within a mineral shell. When this entombment happens, the soft tissue materials escape further degradation (for the most part). In other words, it is a race against time. Can mineral entombment take place before the soft tissue materials fully decompose? If so, then soft tissue remnants can survive for hundreds of millions of years. And any chemical or physical process that can delay the degradation will contribute to soft tissue survival by giving the entombment process time to take place.

In Dinosaur Blood and the Age of the Earth, I describe several mechanisms that likely promote soft tissue survival. Since the book’s publication (2016), researchers have deepened their understanding of the processes that make it possible for soft tissues to survive. The recent work of an international team of collaborators headed by researchers from Yale University provides an example of this growing insight.3

These researchers discovered that the deposition environment during the fossilization process plays a significant role in soft tissue preservation, and they have identified the chemical reactions that contribute to this preservation. The team examined 24 specimens of biomineralized vertebrate tissues ranging in age from modern to the Late Jurassic (approximately 163–145 million years ago) time frame. These specimens were taken from both chemically oxidative and reductive environments.

After demineralizing the samples, the researchers discovered that all modern specimens yielded soft tissues. However, demineralization only yielded soft tissues for fossils formed under oxidative conditions. Fossils formed under reductive conditions failed to yield any soft tissue material, whatsoever. The soft tissues from the oxidative settings (which included extracellular matrices, cell remnants, blood vessel remnants, and nerve materials) were stained brown. Researchers noted that the brown color of the soft tissue materials increased in intensity as a function of the fossil’s age, with older specimens displaying greater browning than younger specimens.

The team was able to reproduce this brown color in soft tissues taken from modern-day specimens by heating the samples and exposing them to air. This process converted the soft tissues from translucent white to brown in appearance.

Using Raman spectroscopy, the researchers detected spectral signatures for proteins and N-heterocycle pyridine rings in the soft tissue materials. They believe that the N-heterocycle pyridine rings arise from the formation of advanced glycoxidation end-products (AGEs) and advanced lipoxidation end-products (ALEs). AGEs and ALEs are the by-products of the reactions that take place between proteins and sugars (AGEs) and proteins and lipids or fats (ALEs). (As an aside, AGEs and ALEs form when foods are cooked, and they occur at high levels when food is burnt, giving overly cooked foods their brownish color.) The researchers noted that spectral features for N-heterocycle pyridine rings become more prominent for soft tissues isolated from older fossil specimens, with the spectral features for the proteins becoming less pronounced.

AGEs and ALEs are heavily cross-linked compounds. This chemical property makes them extremely difficult to break down once they form. In other words, the formation of AGEs and ALEs in soft tissue remnants delays their decomposition long enough for mineral entombment to take place.

Iron from the environment or released from red blood cells promotes the formation of AGEs and ALEs. So do alkaline conditions.

In addition to stabilizing soft tissues from degradation because of the cross-links, AGEs and ALEs protect adjacent proteins from breakdown because of their hydrophobic (water repellent) nature. Water promotes soft tissue breakdown through a chemical process called hydrolysis. But because AGEs and ALEs are hydrophobic, they inhibit the hydrolytic reactions that would otherwise break down proteins that escape glycoxidation and lipoxidation reactions.

Finally, AGEs and ALEs are also resistant to microbial attack, further adding to the stability of the soft tissue materials. In other words, soft tissue materials recovered from fossil specimens are not the original, intact material, because they have undergone extensive chemical alteration. As it turns out, this alteration stabilized the soft tissue remnants long enough for mineral entombment to occur.

In short, this research team has made significant strides toward understanding the process by which soft tissue materials become preserved in fossil remains. The recovery of soft tissue materials from the ancient fossil remains makes perfect sense within an old-earth framework. These insights also undermine what many people believe to be one of the most compelling scientific arguments for a young earth.

Why Does It Matter?

In my experience, many skeptics and seekers alike reject Christian truth claims because of the misperception that Genesis 1 teaches that the earth is only 6,000 years old. This misperception becomes reinforced by vocal (and well-meaning) YECs who not only claim the only valid interpretation of Genesis 1 is the calendar-day view, but also maintain that ample scientific evidence—such as the recovery of soft tissue remnants in fossils—exists for a young earth.

Yet, as the latest work headed by scientists from Yale University demonstrates, soft tissue remnants associated with fossils find a ready explanation from an old-earth standpoint. It has been a gift to science that advances understanding of a sophisticated process.

Unfortunately, for YECs the fossil-associated soft tissues have turned out to be little more than a bad white elephant gift.

Resources:

Endnotes
  1. Mary H. Schweitzer et al., “Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex,” Science 307 (March 25, 2005): 1952–55, doi:10.1126/science.1108397.
  2. John D. Morris, “Dinosaur Soft Parts,” Acts & Facts (June 1, 2005), icr.org/article/2032/.
  3. Jasmina Wiemann et al., “Fossilization Transforms Vertebrate Hard Tissue Proteins into N-Heterocyclic Polymers,” Nature Communications 9 (November 9, 2018): 4741, doi:10.1038/s41467-018-07013-3.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2018/12/19/soft-tissue-preservation-mechanism-stabilizes-the-case-for-earth-s-antiquity

What Does the Discovery of Earth’s Oldest Fossils Mean for Evolutionary Models?

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BY FAZALE RANA – MARCH 29, 2017

Communication can be a complex undertaking. Often, people don’t say what they really mean. And if they do, their meaning is often veiled in what they say. That’s why it’s important to learn how to read between the lines. Understanding the real meaning when something isn’t explicitly stated usually requires experience and some insider’s knowledge.

Thanks to my expertise in biochemistry and origin-of-life research and 20 years of experience as a Christian apologist, I can usually read between the lines when scientists respond to discoveries that challenge the evolutionary paradigm, such as the recently reported discovery of Earth’s oldest fossils. Because of their fear that intelligent design proponents and creationists will make use of these types of discoveries to advance the case for a Creator, scientists can be adept at masking their concern when they discuss the implications of these discoveries. But if you know how to read between the lines, their consternation is as plain as day.

Earth’s Oldest Fossils

An international team made up of scientists from the United Kingdom, United States, Canada, and Australia recently reported on the discovery of microfossils from a geological formation in the northern part of Quebec, Canada.1 Formed from ancient hydrothermal vents, this iron-rich geological system dates somewhere between 3.77 and 4.3 billion years in age.

The putative microfossils consist of microscopic hematite filaments and tubes, like those found in modern hydrothermal vents. Today, iron-oxidizing microbes produce hematite filaments and tubes when sheaths of extracellular materials become coated by iron oxyhydroxide. Added evidence for the biogenicity of these microfossils comes from carbonate and apatite associated with the hematite structures. These compounds can also be produced as by-products of the metabolic activity of microorganisms. The research team also discovered graphite inclusions enriched in carbon-12, a geochemical signature of life. Finally, the Raman spectrum of the carbonaceous deposits display features that also point to the biological origin of this material.

Matthew Dodd, one of the research team members, argues that “we can think of alternative explanations for each of these singular observations, but why all of these features occur together can really only be explained by one thing, which is a biological interpretation.”2

The discovery of these microfossils comes on the heels of the discovery of stromatolites in newly exposed rock outcroppings in Greenland, dating at 3.7 billion years.3 Both recent discoveries corroborate earlier work that yielded several different geochemical markers for biological activity. In short, an impressive weight of evidence points to the early appearance of complex and diverse microbial life on Earth.

Skepticism about Bioauthenticity

Despite this impressive collection of evidence, several scientists have expressed skepticism about the bioauthenticity of the fossils. Journalist Sarah Kaplan explains why: “Findings like these are subject to intense scrutiny because they have potentially far-reaching implications for the study of early organisms on Earth and other planets.”4

As I have discussed previously when the discovery of 3.7-billion-year-old stromatolite fossils were unearthed in Greenland, one of the implications of the early appearance of metabolically complex and diverse microbial life on Earth is that it calls into question evolutionary explanations for the origin of life. These discoveries indicate that life appeared suddenly on Earth, in a geological instant. Yet traditionally, origin-of-life researchers maintained that life’s origin via chemical evolution would have required hundreds of millions of years, perhaps even a billion years.

This concern can be read between the lines in the objections raised by scientists responding to this discovery.

Some argue that the research team hasn’t amassed enough evidence to convince them of the biogenicity of the fossils, pointing out that extraordinary claims require extraordinary evidence. But the claim that life appeared early in Earth’s history is only extraordinary within the evolutionary paradigm. To view these microfossils as extraordinary highlights the trouble these fossil finds cause for an evolutionary approach to the origin-of-life question.

Others argue that iron-oxidizing microbes are too complex to have appeared this early in Earth’s history. Some assert that the rock layers containing the fossils are much younger than 3.77 billion years, raising concerns about the dating methods used to determine the age of the rocks harboring the microfossils. Again, both complaints reveal concerns about the impact that this fossil find has on the evolutionary explanation for life’s beginning. The hope is that by forcing the fossils to appear much later in Earth’s history, scientists can explain the metabolic complexity of the organisms that produced the hematite deposits by giving evolutionary processes more time. Yet there is no reason to dispute the dates for the rock formations in northern Canada, and the case for the biogenicity of the fossils is strong.

Some dismiss the bioauthenticity of the microfossils because it would require life to originate under hostile conditions, caused by the late heavy bombardment. These hostile conditions would have frustrated the origin-of-life process, potentially sterilizing Earth, making it difficult to imagine how life could have emerged, let alone diversified, at 3.77 billion years ago—at least from an evolutionary vantage point. If these fossils aren’t authentic, then scientists don’t have to confront the counterintuitive fact that life appeared under hostile conditions.

It seems to me that these scientists are dangerously close to evaluating the validity of the 3.77-billion-year-old microfossils based on how well they fit into the evolutionary paradigm, instead of evaluating evolutionary explanations for the origin of life based on the fossil evidence—a complete reversal of the way that the scientific method is supposed to work.

Nevertheless, a quick read between the lines reveals just how awkwardly this fossil find fits within the evolutionary paradigm.

Implications for Creation Models

Though the discovery of 3.77-billion-year-old microfossils confounds evolutionary origin-of-life models, it affirms RTB’s origin-of-life model. As described in Origins of Life, two key predictions of this model include (1) life appearing on Earth soon after the planet’s formation and (2) first life possessing intrinsic complexity. And these predictions are satisfied by this latest advance.

The writing is on the wall: the case for a Creator’s role in the origin of life is becoming more and more evident.

Resources

Endnotes

  1. Matthew S. Dodd et al., “Evidence for Early Life in Earth’s Oldest Hydrothermal Vent Precipitates,”Nature 543 (March 2017): 60–64, doi:10.1038/nature21377.
  2. Sarah Kaplan, “Newfound 3.77-Billion-Year-Old Fossils Could Be Earliest Evidence of Life on Earth,” Washington Post, March 1, 2017, https://www.washingtonpost.com/news/speaking-of-science/wp/2017/03/01/newfound-3-77-billion-year-old-fossils-could-be-earliest-evidence-of-life-on-earth.
  3. Allen P. Nutman et al., “Rapid Emergence of Life Shown by Discovery of 3,700-Million-Year-Old Microbial Structures,” Nature 537 (September 2016): 535–38, doi:10.1038/nature19355.
  4. Kaplan, “Newfound 3.77-Billion-Year-Old Fossils.”
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2017/03/29/what-does-the-discovery-of-earth-s-oldest-fossils-mean-for-evolutionary-models