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Re: Schweizter and Soft Tissue Recovery



**damn, did it again, replied to sender, not to the list**

They found matches to everything and anything, if I recall. It isn't
too informative in that respect, because there's going to be genetic
material shared between humans, dinos, insects, etc. So matches aren't
super informative. They analyzed, again if I recall correctly, some of
the avian matches further and were surprised to see that the matches
were /too/ good, which they interpreted as not merely Turkey and
Ostrich like, but actual Turkey and Ostrich. (of course, Ostrich don't
waddle around in Montana, so that seems an unlikely source).

I recall also that they reported that most archaeological metagenomic
analyses recovered something-like 30% (or 40%, or somesuch) DNA from
their fossils and samples, but that the few Mesozoic metagenomic
analyses had recovery levels of something-like 80%. IOW, 'uh oh'
there's a problem.



On Fri, Nov 11, 2011 at 11:01 AM, Robert Schenck <schenck.rob@gmail.com> wrote:
> They found matches to everything and anything, if I recall. It isn't
> too informative in that respect, because there's going to be genetic
> material shared between humans, dinos, insects, etc. So matches aren't
> super informative. They analyzed, again if I recall correctly, some of
> the avian matches further and were surprised to see that the matches
> were /too/ good, which they interpreted as not merely Turkey and
> Ostrich like, but actual Turkey and Ostrich. (of course, Ostrich don't
> waddle around in Montana, so that seems an unlikely source).
>
> I recall also that they reported that most archaeological metagenomic
> analyses recovered something-like 30% (or 40%, or somesuch) DNA from
> their fossils and samples, but that the few Mesozoic metagenomic
> analyses had recovery levels of something-like 80%. IOW, 'uh oh'
> there's a problem.
>
> On Thu, Nov 10, 2011 at 6:43 PM, Heinrich Mallison
> <heinrich.mallison@googlemail.com> wrote:
>> If the material leaked in we should see a match mainly to beetles and
>> mammals and birds. If it is dinosaurian, we should see a match to
>> birds and crocs, period.
>>
>> Now if I could only recall what the results of the study were....
>> ___________________________________
>> Dr. Heinrich Mallison
>> Abteilung Forschung
>> Museum für Naturkunde - Leibniz-Institut
>> für Evolutions- und Biodiversitätsforschung
>> an der Humboldt-Universität zu Berlin
>> Invalidenstrasse 43
>> 10115 Berlin
>> Office phone: +49 (0)30 2093 8764
>> Email: heinrich.mallison@gmail.com
>> _____________________________________
>> Fere libenter homines id quod volunt credunt.
>> Gaius Julius Caeser
>>
>>
>>
>>
>> On Fri, Nov 11, 2011 at 12:09 AM, Robert Schenck <schenck.rob@gmail.com> 
>> wrote:
>>> At the SVP meeting, there was an interesting investigation on the
>>> metagenomics of dinosaur soft tissue preservation. The gist of it was
>>> that the material recovered from Mesozoic fossil bone had gene &
>>> protein material that matched WAY too many living things, and matched
>>> them WAY too perfectly. One thing to be 'turkey-like' (and therefore
>>> distantly related to birds), another to be a plain old turkey. The
>>> authors at the talk supposed that genetic and protein material had
>>> leached through the soils, and invaded the fossil bones (Researchers
>>> in the tropics, as far as I understand it, do (somewhat similar)
>>> environmental DNA sampling to ID the different genetic types of things
>>> that are out in the forest (w/o having to ID the living animal).
>>> That's a pretty fascinating discovery in and of itself. They also felt
>>> that bacteria could make (and indeed showed similar) tubular
>>> structures that look like blood vessels.
>>>
>>> Later I noticed a poster from (if I recall correctly) someone in Dr.
>>> Schweitzer's group identifying the material in the soft tissue as
>>> definitely collagen.
>>>
>>> So what does anyone think about this, seems like the issue is still
>>> open, and this material was recovered quite a while ago.
>>>
>>> Has there been any sectioning of the 'goop' that Dr. Schweizter found,
>>> for histological examination (beyond what she's already done)? Does it
>>> react with biological stains that can distinguish between material
>>> like collagen and bacterial films? If genes and proteins from the
>>> environment are leaching into the fossil, should'nt they also be in
>>> the surrounding rock, indeed, might it be possible to detect higher
>>> concentrations closer to the surface and outside the bones? Coring at
>>> the site might be informative in that respect.
>>>
>>> It it's dinosaurian, I'd expect the center of the bone to have the
>>> highest concentration of material (goop, genes, proteins), if it's
>>> leaching, i'd expect the opposite. Seems like that sort of analysis
>>> could be done.
>>>
>>> --
>>> Robert J. Schenck
>>> Kingsborough Community College
>>> Physical Sciences Department
>>> S332 ph# 718-368-5792
>>> Follow Me on Twitter: @Schenck
>>> KCC Class Schedule on Google Calendar: http://tinyurl.com/mqwlcy
>>>
>>
>
>
>
> --
> Robert J. Schenck
> Kingsborough Community College
> Physical Sciences Department
> S332 ph# 718-368-5792
> Follow Me on Twitter: @Schenck
> KCC Class Schedule on Google Calendar: http://tinyurl.com/mqwlcy
>



-- 
Robert J. Schenck
Kingsborough Community College
Physical Sciences Department
S332 ph# 718-368-5792
Follow Me on Twitter: @Schenck
KCC Class Schedule on Google Calendar: http://tinyurl.com/mqwlcy