Tag: keratin

Science News Flash: An Old-Earth Perspective on Dinosaur Feathers Preserved in Amber

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BY FAZALE RANA – DECEMBER 9, 2016

Whenever we are in a foreign country, my wife loves to shop at local, out-of-the-way markets. She always finds some of the most interesting souvenirs.

It turns out the same is true for paleontologist Lida Xing who purchased several amber pieces from a market in Myitkyina in the country of Myanmar. The amber sold at the market comes from a nearby mine in the Hukawng Valley. While most buyers are looking for amber to make jewelry, Xing was looking for amber with inclusions of plant and animal remains. The amber from the mine dates to 99 million years. Because of the amber’s age, the well-preserved plant and animal remains entombed by this fossilized tree resin offer a unique glimpse at ancient life on Earth, providing details and insight that far exceed those available from highly compressed fossil remains that typically comprise the fossil record.

As fate would have it, one of the amber pieces Xing purchased contains a piece of a dinosaur tail (perhaps from a maniraptor) with attached feathers! This discovery is described in a paper that will appear in the December 19 issue of Current Biology.1 Yesterday the paper was published online ahead of the publication date and it has already generated headlines both in the popular news and on social media.

This is not the first time researchers have discovered feathers preserved in amber. But it isthe first time they have observed feathers associated with parts of a dinosaur, in this instance a section of the tail (near the middle or end) that includes eight vertebrae. The anatomical features clearly indicates that the preserved tail belongs to a large group of dinosaurs labeled the coelurosaurs.

It goes without saying that this find has already caused quite a bit of a stir because of its important implications for evolutionary and creation models for bird origins.

An Evolutionary Perspective of the Discovery

For many in the scientific community this discovery further affirms the evolutionary link between birds and dinosaurs, with feathered dinosaurs viewed as transitional intermediates. Along these lines, the researchers describe the dinosaur feathers preserved in amber as transitional, noting that the feather’s central shaft (rachis) is poorly defined. On this basis, the researchers argue that the rachis was a late-appearing feature in feathers, forming when the barbs of the feather fused together.

An Old-Earth Creationist Response

As an old-earth creationist, I’m skeptical about the evolutionary account that has birds evolving from theropods. In fact, this latest discovery only adds to my skepticism.

Paleontologists interpret feathered dinosaurs from the fossil record as transitional intermediates between theropods and birds—including the feathered dinosaur tail found in amber. Yet, each occurrence of feathered dinosaurs in the fossil record appear after the first true bird, Archaeopteryx.2 Based on the fossil record, this ancient bird appeared on Earth around 155 million years ago. Archaeopteryx’s feathers were identical to the feathers of modern birds. In fact, the same research team discovered bird feathers in 99-million-year-old amber from the same source that yielded the amber with the dinosaur feathers. The bird feathers, like those of Archaeopteryx, are identical to those found in modern birds.

It is hard to imagine how the “primitive” feathers associated with the dinosaur tail (again, dated at 99 million years in age) could be transitional if they appear over 50 million years after Archaeopteryx and co-occur with feathers from a bird belonging to enantiornithes.

This problem is not unique to the bird fossil record. There are several instances in which presumed transitional forms appear in the fossil record well after the first appearance of their “evolutionary descendants.” In fact, paleontologist have a name for this phenomenon: a temporal paradox.

For a more complete discussion of the problems I see with the proposed evolutionary link between birds and theropod dinosaurs, see “Birds in the Fossil Record” (listed in the resource section below).

A Young-Earth Creationist Perspective of the Discovery

One exciting aspect of this find is the possibility that soft-tissue remnants associated with the features may be preserved in the amber. The researchers discovered iron (in the ferrous form) associated with the carbonized feather remains. They speculate that this iron derives from hemoglobin originally found in the tail muscle tissue. On this basis, the research team speculates that soft-tissue remnants derived from keratin may be present in the amber-entombed specimen.

In recent years, young-earth creationists have made use of these types of finds to argue that it is impossible for such fossils to be millions of years old. They argue that soft tissues shouldn’t survive that long. These materials should readily degrade in a few thousand years. In their view, these finds challenge the reliability of radiometric dating methods used to determine the age of these fossils, and along with it, Earth’s antiquity. Instead, they argue that 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.

An Old-Earth Creationist Response

These types of claims prompted me to write Dinosaur Blood and the Age of the Earth. In this work (and elsewhere), I explain why the recovery of soft-tissue remnants associated with fossil finds is illegitimate evidence for a young Earth.

Given the structural robustness of keratin, and the preservative effect of ferrous iron, it is completely reasonable to think that keratin remnants associated with the feathers could survive long enough to be completely entombed by the amber and eventually persist for nearly 100 million years.

Though this find will be interpreted by the scientific community from an evolutionary vantage point and, more than likely, opted by young-earth creationists to challenge the antiquity of Earth and life on Earth, the dinosaur feathers entombed in amber can readily be accommodated from an old-earth creationist vantage point.

Resources

Creation vs. Evolution Controversy

“Is There a Controversy about Evolution?” by Fazale Rana (article)
“The Creation-Evolution Controversy in Jurassic World” by Fazale Rana (article)

Age-of-the-Earth Controversy

“Dinosaur Blood and the Age of the Earth” by Fazale Rana (book).
“Can Keratin in Feathers Survive for Millions of Years?” by Fazale Rana (article)

Endnotes

  1. Lida Xing et al., “A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber,” Current Biology 26 (December 19, 2016): 1–9, doi:10.1016/j.cub.2016.10.008.
  2. Some paleontologists claim that the temporal paradox for bird origins was solved based on the discovery of a feathered theropod that dates between 151 and 161 million years in age. (See Dongyu Hu et al., “A Pre-Archaeopteryx Troodontid Theropod from China with Long Feathers on the Metatarsus,” Nature 461 [October 1, 2009]: 640–43, doi:10.1038/nature08322.) However, at best, this find demonstrates the co-occurrence of feathered dinosaurs and the first true bird, when the error bars of the age-date measurements are taken into account.
  3. Lida Xing et al., “Mummified Precocial Bird Wings in Mid-Cretaceous Burmese Amber,” Nature Communications 7 (June 28, 2016): 12089, doi:10.1038/ncomms12089.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2016/12/09/science-news-flash-an-old-earth-perspective-on-dinosaur-feathers-preserved-in-amber

Can Keratin in Feathers Survive for Millions of Years?

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BY FAZALE RANA – AUGUST 10, 2016

I don’t like conflict. In fact, I try to avoid it whenever possible. And that’s part of the reason I never wanted to become directly involved in the young-earth/old-earth controversy that takes place within the church.

Frankly, I find the debate tedious, and a distraction from the real work at hand: helping skeptics and seekers recognize the scientific evidence for God’s existence and Scripture’s reliability.

Of course, if people ask me age-of-the-earth questions, I am quick to explain why I hold to an old-earth/day-age interpretation for Genesis 1 and what I see as biblical, theological, and scientific issues with a young-earth/calendar day interpretation of the Genesis 1 creation account.

Soft Tissues in Fossils and the Age of the Earth

Over the course of the last few years, one question that has come up a lot relates to the discovery of soft tissue remnants in fossils, such as the blood cells and blood vessels remains recovered from a T. rex specimen that age-dates to 68 million years old. Young earth creationists make use of these surprising results to argue that it is impossible for fossils to be millions of years old. They argue that soft tissues shouldn’t survive that long. These materials should readily degrade in a few thousand years. In their view, these finds challenge the reliability of radiometric dating methods used to determine the age of these fossils, and along with it, Earth’s antiquity. Instead, they argue that 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.

Because I’m a biochemist—and an old earth creationist—people frequently ask me how I make sense of the T. rex find and the discovery of other types of soft tissue remnants in the fossil remains of other creatures that age-date to several hundred million years, in some cases.

Dinosaur Blood and the Age of the Earth

These queries eventually motivated me to write Dinosaur Blood and the Age of the Earth. And I am glad I did. Aside from the young-earth/old-earth debate, the scientific questions related to soft tissue finds in fossils are captivating.

The central question of Dinosaur Blood and the Age of the Earth centers around soft tissue durability: If radiometric dating is reliable, then how is it possible for soft tissue remnants to persist for millions of years?

Recent work by a research team at North Carolina State University (NC State)—headed up by Mary Schweitzer—helps address this question, specifically focusing on beta-keratin fragments recovered from the fossilized feathers and claws of Shuvuuia deserti and Rahonavis ostromi.1

How Can Keratin Survive in Fossils?

As I discuss in Dinosaur Blood and the Age of the Earth, some biomolecules (such as keratins) form extremely stable structures that delay their degradation. Keratins have a number of structural features (such as extensive crosslinking) that helps explain why fragments of these proteins could survive for tens of millions of years, under the right conditions.2 But my analysis was theoretical. Even though my assessment was based on sound biochemical principles, it would be nice to have some corroborating experimental evidence to support my claims. (The old saying in science applies: “theories guide, experiments decide.”) And that is precisely what the NC State researchers provide in their recent study.

Feather Decomposition

Schweitzer and her team conducted a ten-year experiment to gain insight into the natural degradation processes of feathers (and other biological materials made up of keratins such as skin, claws, beaks, and hair). To do this, they exposed feathers from a Hungarian partridge to a variety of conditions, and then analyzed the samples busing: (1) transmission electron microscopy (TEM) to monitor changes in the fine structure of the feather’s anatomy; and (2) a technique called in situ immunofluorescence to determine if pieces of keratin proteins persisted in the feather remains.

Of particular interest is the feather samples Schweitzer and her team wrapped in aluminum foil and heated in an oven for 10 years at 630°F—conditions used to sterilize glassware. Many paleontologists consider high heat to be a proxy for deep time.

Perhaps it is no surprise, when viewed under a microscope, the macroscopic features of feathers treated at high temperatures were completely lost. Instead the only thing visible were shiny black pieces of “charcoal-like” material. Yet, when examined at high magnification with a TEM, the investigators were able to visualize fragments of feather barbs. Using their immunofluorescence technique, the researchers were able to detect clear evidence of keratin fragments in the sample.

These observations align with my thoughts about keratin’s durability, making it all the more reasonable to think that soft tissue remnants persist in millions-of-years old fossil remains. In fact, when the researchers applied their immunofluorescence to the Shuvuuia desertisamples, once again, they found evidence for keratin fragments in these fossil remains.

Preservation Mechanisms

As I point out in Dinosaur Blood and the Age of the Earth, molecular durability alone isn’t sufficient to account for soft tissue survivability. For soft tissue remnants to persist in fossil, the rate of fossilization has to outpace the rate of soft tissue degradation. When that happens, a mineral ‘casing’ will entomb the soft tissue before it completely decomposes, preserving it for paleontologists to later discover. In addition to molecular durability, scientists have identified a number of mechanisms that contribute to both the degradation and preservation of soft tissues during the process of burial and fossilization.

Along these lines, the NC State scientists speculate on processes that might extend keratin’s survivability in feathers—at least, long enough for mineral entombment to occur. They think one of their observations about the high-heat sample offers a clue. The research team noted that melanosomes (the organelles that harbor pigments, giving feathers their colors) were absent after heating for ten years at 630°F. On this basis, they conclude that paleontologists have made a mistake when they interpret microbodies as melanosomes in fossilized feathers. Instead, they think that the mirobodies derive from microbes.

This reinterpretation is good news for keratin preservation on two accounts. It is true that microbial activity can destroy soft tissues, but the NC State scientists think it can also help speed up the fossilization process leading to the preservation of keratin remnants. How? Because microbes secrete materials (called exopolymeric substances) that promote deposition of minerals, speeding up the entombment of the soft tissue. Additionally, the NC State researchers think that melanosome degradation may also be important. When these organelles break down, they release their contents (eumelanin) which may function like a fixative, slowing down tissue degradation long enough for the soft tissue to be entombed.

The NC State study has unearthed fascinating details regarding feather decomposition and provides key insights that help account for the persistence of keratin in fossilized remains of reptiles, birds, and feathered dinosaurs that date to tens of millions of years old.

Resources
“Structure of Collagen Unravels the Case for a Young Earth” by Fazale Rana (Article)
Dinosaur Blood and the Age of the Earth by Fazale Rana (Book)

Endnotes

  1. Alison Moyer, Wenxia Zheng, and Mary Schweitzer, “Keratin Durability Has Implications for the Fossil Record: Results from a 10 Year Feather Degradation Experiment,” PLoS One 11 (July 2016): e0157699, doi:10.1371/journal.pone.0157699.
  2. Fazale Rana, Dinosaur Blood and the Age of the Earth (Covina, CA: RTB Press, 2016), 57–58.
Reprinted with permission by the author
Original article at:
https://www.reasons.org/explore/blogs/the-cells-design/read/the-cells-design/2016/08/10/can-keratin-in-feathers-survive-for-millions-of-years