The "Iron Based" concept has been refuted.
Creation Research Quarterly Volume 51 Spring 2015 number 4
Analysis of Preservation Motifs
Schweitzer et al. (2013a, 2013b) have proposed numerous possible explana- tions for the survival of recovered colla- gen and other soft tissue materials found in T. rex and B. canadensis including for example molecular sheltering, hydro- phobic enrichment, iron-protein block- ing, cross-linking, etc. Undoubtedly all if not most of the proposals have some merit. However, in our view, the matter of these mechanisms explaining deep time survival has not been adequately supported either empirically or by literature review. We begin by merely pointing out that the Fenton chemistry hypothesis supported by the ostrich tis- sue preservation experiment over 2 years, using hemoglobin as a preservative is simply inadequate to extrapolate and infer stabilization over 68 million years. It is unknown if environmental factors like high-low temperature cycling or dehydration might radically alter the test specimens appearance. Is a tissue specimen soaked in blood kept in a laboratory an adequate experiment to model the environmental weathering of postmortem tissue? In this vein, it is again trivially pointed out that the visual inspection method of tissue analysis is woefully inadequate to draw any conclusions concerning a molecular mechanism of stabilization. The group has access to mass spectra evaluation which could have identified footprints of hydroxyl radical presence. As we shall see, a more careful analysis of the mass spectral data related to the particular peptides and sequences shows that some doubt, if not complete rejection, of several preservation motifs is war- ranted. The particular motif that intro- duces more problems than it purportedly solves concerns Fenton chemistry iron fixation of the peptides.
The proposal is essentially hydroxyl free-radical infiltration into soft tissue. The free radicals are generated by iron- biominerals with which the tissue is combined. Success of this mechanism depends upon deployment of the free radicals through an aqueous medium in contact with the polypeptide. We hold that “chemical fingerprints” of this activity should be registered upon the peptides themselves. For example, hydrolytically sensitive amino acids (asparagine, glutamine) should have degraded and free-radical sensitive com- pounds (tyrosine) should have reacted. These observations may seem like an unnecessary if not insignificant detail to observe but recall that the specimens have been in the ground for some 68 million years. If a chemical mechanism (Fenton chemistry or iron mediated hy-droxyl radical fixation) is to be believed, its entire consequent (fugitive water and hydroxyl radicals dosing the peptide remnants) ought to have occurred. Be- low we set out upon an inspection of two general ideas concerning the presence of water and hydroxyl free radicals and their potential signature upon peptide chemistry.