DNA at “higher temperatures” doesn’t nullify abiogenesis.

From: General Han Solo​​​​

In regards to this statement about DNA and a “higher temperature” that nullifies abiogenesis, I advise that TE (TrueEmpricism) takes a look at the recent findings of DNA surviving reentry through the Earth’s atmosphere:
“Functional Activity of Plasmid DNA after Entry into the Atmosphere of Earth Investigated by a New Biomarker Stability Assay for Ballistic Spaceflight Experiments”

– http://journals.plos.org/plosone/article/asset?id=10.1371/journal.pone.0112979.PDF

Most curious is this statement on page 18:

Due to the spin of the payload during ascent and the circular application of the samples, all application sites were equally exposed to high temperatures of up to 118°C. Additionally, the DNA was exposed to temperatures between 80–100°C during the microgravity phase and up to 130°C during ascent and descent phase. The random exposure of the samples to the constantly high temperatures weakens the phosphodiester bond which leads to hydrolysis resulting in single and double strand breaks. The temperature induced DNA damage could explain the different degrees of degradation visible in the agarose gel electrophoration. Futhermore, it is likely that sample quantities are partially reduced during the landing procedure when the payload is landing on ice and snow. Compared to the sample application directly onto the payload surface, small niches in the grooves of the screw heads provided a certain degree of protection against maximum temperatures, and we observed the highest degree of protection on the bottom side. However, intact DNA was detectable for all sample application sites.

We therefore conclude that the minimal protection given by the grooves on the surface of the payload structure, as well as by the grooves of the screw heads combined with the observed relatively thick layer (21 mm) of DNA and salt crystals was sufficient for at least a fraction of the DNA molecules to stay intact and retain their full function. The protective role of so called biofilms have been already shown for spores. Additionally, high salt concentration can have a beneficial effect on DNA denaturation and degradation. Salts like MgCl2 and KCl counteract the denaturation of double-stranded DNA at high temperature, and renaturation of single-stranded products of thermodegradation is favoured when the temperature of the incubation mixture decreases. A protective effect of salt crystals for the survival of bacteria under vacuum and UV conditions were reported also earlier. The fact that DNA is susceptible to high temperature was already shown by several groups before. Chiter and colleagues who analysed the transfer of genetic modified organisms in form of DNA fragments could show that temperatures above 95°C for more than five minutes lead to a high level of DNA fragmentation so that it is unlikely that genetic information is retained.

For further information, this was discussed by Dr. Fazale Rana on this podcast recording: http://www.reasons.org/podcasts/apologia-free/dna-can-survive-reentry-from-space

– General Han Solo

Author: Steve McRae

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