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by Brian Thomas, Stephen Taylor, and Kevin Anderson The presence of short-lived soft tissue in fossils has proven challenging for uniformitarians to explain. Wiemann and co-authors describe a mode of preservation that may help explain the presence of primary protein remnants in fossil biomineralised tissues, including scales, teeth, eggshell, and bone. They showed results consistent with peptide cross-linking that forms N-heterocyclic polymers early in diagenesis. Advanced Glycoxidation End-products (AGEs) and Advanced Lipoxidation End-products (ALEs) are a heterogeneous group of water-insoluble compounds generally formed by oxidation reactions. AGEs and ALEs resist water, chemicals, and microbes. They supposedly shrink-wrap adjacent proteins or proteinaceous remnants to shield them over deep time. The researchers summarized this preservation mode by saying: “The generation of brown-stained proteinaceous material, and subsequently non-proteinaceous AGEs [Advanced Glycoxidation End-products] and ALEs [Advanced Lipoxidation End-products], provides an explanation for the apparent anomaly of widespread morphological and molecular preservation of soft tissues in fossil vertebrate hard tissues. Both AGEs and ALEs exhibit hydrophobic behavior due to the chemical character of their crosslinks, which in turn shield adjacent peptides from hydrolysis. Thermo-oxidatively induced, intensive crosslinking of proteins results in hydrophobic, reinforced AGE/ALE scaffolds resistant to microbial digestion. This explains the preservation of fragile soft tissues in …
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