Amino Acids Found in Cretaceous Amber
If this doesn’t take the cake for soft tissue preservation: intact amino acids in amber said to be 100 million years old!
Even this one evoked a ‘wow’ response from Jon Tennant at the PLoS Paleontology Community blog. On April 23, McCoy et al in Nature Scientific Reports announced “Ancient amino acids from fossil feathers in amber.” Tennant writes,
Then [sic, the] fossil record some times [sic] is one of those things which just stops you dead in your tracks, with ‘wow’ written all over your face. Today, one of those moments just happened. Researchers have now discovered fossilised amino acids, entombed for more than 100 million years in amber.
Now, this is not the first time such things have been discovered. Typically, when proteins have been found fossilised it has been within bones from large, terrestrial vertebrates. This is the first time they have been discovered within amber, within a smaller organism.
The bones of large vertebrates he mentions undoubtedly refer to the T. rex found by Mary Schweitzer in 2005, and subsequent finds of dinosaur soft tissue (see Bob Enyart’s growing list). “Critically, amber allows the exceptional preservation of the organic soft tissues, right down to the microscopic scale,” Tennant says. “This includes amino acids.” Amino acids are the building blocks of proteins.
The Racemization Clock
Because life uses only left-handed amino acids, any fossil that preserves left-handed forms is assumed to be recent. Proteins switch from all left-handed to a mixture of left- and right-handed amino acids, a process called racemization. A fossil with a mixture of left- and right-handed amino acids, therefore, is assumed to be ancient. The paper’s Abstract explains,
Ancient protein analysis is a rapidly developing field of research. Proteins ranging in age from the Quaternary to Jurassic are being used to answer questions about phylogeny, evolution, and extinction. However, these analyses are sometimes contentious, and focus primarily on large vertebrates in sedimentary fossilisation environments; there are few studies of protein preservation in fossils in amber. Here we show exceptionally slow racemisation rates during thermal degradation experiments of resin enclosed feathers, relative to previous thermal degradation experiments of ostrich eggshell, coral skeleton, and limpet shell. We also recover amino acids from two specimens of fossil feathers in amber. The amino acid compositions are broadly similar to those of degraded feathers, but concentrations are very low, suggesting that much of the original protein has been degraded and lost. High levels of racemisation in more apolar, slowly racemising amino acids suggest that some of the amino acids were ancient and therefore original. Our findings indicate that the unique fossilisation environment inside amber shows potential for the recovery of ancient amino acids and proteins.
The rate of racemization is poorly known. The scientists ran some experiments encasing modern proteins in resin for 504 hours (3 weeks) at high temperature (170 C) and found very low rates of racemization. 100 million years, however, is a very long time – some nine orders of magnitude longer. Could amino acids survive at all for such a long time? Even allowing for different environmental conditions, histories, and chemical compositions of amber, preservation at all seems unreasonable. Proteins can be degraded by diffusion, cosmic rays and other variables in addition to amino-acid racemization, especially outdoors. Protected lab conditions may not represent the true decay rate.
Another remarkable amber specimen was reported by Science Daily: “Dwarfs under dinosaur legs: 99-million-year-old millipede discovered in Burmese amber.” No preserved proteins or amino acids are reported in the press release. This millipede is also dated back into the Cretaceous. As usual, the scientists’ focus is on evolution:
To analyse the species and confirm its novelty, the scientists used 3D X-ray microscopy to ‘slice’ through the Cretaceous specimen and look into tiny details of its anatomy, which would normally not be preserved in fossils. The identification of the millipede also presents the first clue about the age of the order Callipodida, suggesting that this millipede group evolved at least some 100 million years ago. A 3D model of the animal is also available in the research article.
The discovery was published in the journal ZooKeys. It contains an evolutionary conundrum stuffed into Darwinism against expectations:
While the callipodidan habitus seems to have remained generally unchanged for at least 99 million years, pleurotergal and hypoproctal setation, as well as the complexity of eyes in ground-dwelling forms may have evolved recently in the order.
The Moyboy Paradigm Trap
Significant contamination, however, is unlikely due to the strong feather signal in the amino acid composition. Moreover, other researchers have found that keratin proteins preserve even into the Jurassic, suggesting that Cretaceous keratin preservation is not at all unexpected or unreasonable.
They refer back to seven papers by Mary Schweitzer, the best-known discoverer of dinosaur soft tissue. These scientists’ reasoning is, ‘If Schweitzer says Jurassic soft tissue can survive 100 million years or more, then we aren’t surprised to find amino acids in our sample.’ Nobody seems to have the courage to step out of the moyboy paradigm and think for themselves. Are such long ages reasonable?
In his ‘wow’ moment, did Jon Tennant think to question his assumptions? Did he think outside the box for a moment to question whether amino acids could survive ten thousand years, let along 100 million years? Not at all. His worldview gravitated to the only thought in his head:
As the authors state: “…identification of protein sequences from fossil feathers, combined with their morphological investigation, would allow important functional and evolutionary information to be determined over long timescales.”
So this is a really cool step closer to understanding the physiology and evolution of dinosaurs and birds, that just a few years ago would have been virtually unthinkable!
Conclusions are subservient to paradigms, which are subservient to worldviews. Brute facts, however, are what they are.
Myths can be perpetuated in scientific papers by one group of authors simply trusting the assumptions of a previous author. And one of the foundational assumptions of the moyboy paradigm is that Darwin needed long ages to evolve people from bacteria ancestors.