Forgive Me If You’ve Heard This One Before…

The DpSU for Thursday the 15th is called Evolution Can’t Explain Organic Fossils and is on precisely the same Cuttlefish chitin study as yesterday.

The obvious response to that is that it’s not evolution that’s supposed to explain soft-tissue preservation. Also of note is that he hasn’t made a much better case than he did last time.

Some highlights:

• He spends a lot of time going through two other, quite old studies that show that an ‘anoxic’ environment is not sufficient to preserve chitin from bacteria. Nevertheless, that is not all that was protecting these fossils. To quote this paper:
  

  One key to the preservation of organic tissues, in particular chitin and chitosan, is cessation of bacterial degradation within environments of deposition. Bacterial breakdown of polymeric molecules is accomplished through activities of both free extracellular enzymes (those in the water column) and ektoenzymes (those on the surface of the microbial cell) such as chitinases [31], [32]. Chitinases function either by cleaving glycosidic bonds that bind repeating N-acetyl-D-glucosamine units within chitin molecules or by cleaving terminal N-acetyl-D-glucosamine groups [33]–[35]. These enzymes adsorb to the surface of clay particles, which inactivates them [33]–[35]. Strong ions in solution like iron may act in the same manner [33]. Once bound to functional groups within these polymeric molecules, Fe²⁺ ions prevent specific bond configuration on the active-site cleft of specific bacterial chitinases and prevents hydrolysis [31], [33], thus contributing to preservation.

  Additionally, there were other barriers such as mineralised material that prevented bacteria gaining access.

• He also mentions the “biochemical decay” of chitin without bacterial activity, but once again gives no reference to give an indication of the time scale required for chitin to degrade completely via such method. For all he’s telling us it can survive – at least in the degraded state found – for all eternity.
• This time he noticed the Paleozoic ‘chitin-protein signatures’ referred to in the first quote from the paper that I gave yesterday, but does not mention the ‘signatures’ aspect which rather lessens the degree to which you can make pronouncements based on it.
• The Cuttlefish were apparently “buried in uniquely catastrophic circumstances that were nothing like modern aquatic ecosystems.” What he bases that claim on I’m not entirely sure.
• He says that “geologists who subscribe to the global Flood described in the Bible attribute [Paleozoic rock layers] to world-covering wave pulses in the early and middle phases of the Flood year only thousands of years ago.” B.T. has a habit of tossing around odd Flood ideas without necessarily believing in them himself, so this is no indication as to whether the ICR actually ascribes to the idea that only parts of the earth were covered via the floodwaters at any given time.
• And, for once, he mentions his list of soft tissue finds summarised here – I’d almost thought he’d forgotten it.

Interestingly, while most DpSUs are, judging by the dates given in footnotes in the form of “accessed <Month> <Date>, <Year>”, written at least a fortnight before publication, this article may have been typed up as recently as the last few days – it says, for example, “See Published Reports of Original Soft Tissue Fossils. Institute for Creation Research. Posted on icr.org, accessed December 13, 2011.” Why he did this I have no idea. It’s possible that it was an Acts & Facts rewrite that they decided wouldn’t get used and published anyway. Unless he intends to tell us we probably wont ever know the answer.