Gday all
Steven Avery wrote: ↑Fri Jul 27, 2018 5:41 am
As you pointed out, you might easily find flora and fauna that really fits one scenario over another.
Presumably you mean that the DNA of sheep/lambs may be different between the 1st century vs the 19th century, right ?
So that a DNA test revealing the vellum of Sinaiticus was from the 19th century would prove it a forgery, right ?
A fair point, sheep have changed a bit in two millenia I daresay, let's look -
Here is a more recent study (than Prof. Stinson's) of DNA in 700 year old vellum MSS, from 2014 :
https://www.futurity.org/parchments-anc ... ck-815322/
http://rstb.royalsocietypublishing.org/ ... 0130379%20
But it still only tells us : "what kind of animals were used to make the parchments".
Apparently the Booroola (FECB) sheep mutation dates back only to the 18th century :
https://academic.oup.com/biolreprod/art ... 69/2723999
That sounds promising.
Merino sheep are only a couple of centuries old, sheep in the middle ages were rather different breeds, but it's not clear how these breeds differed genetically :
http://www.katiecannonscraft.com/sheep-medieval/
A genome for each breed would clarify that, but so far all we have is the one breed - Texel AFAIK.
Here is a detailed scholarly paper looking into the speciation of modern sheep :
https://www.ncbi.nlm.nih.gov/pmc/articl ... 028771.pdf
It's rather above my pay-grade, but the times they cite are often in mega years and the species cluster diagrams cover 500 kyears and 125 kyears.
Some references to only millenia include :
"Only a small number of substitutions have then accumulated in the ca. 11 000 years (Ryder 1984) of further breeding. These do not allow further differentiation of the domestic sheep based on mtDNA data using the current approach and thus lead to the unresolved branching pattern and short branches within the two clusters of domestic sheep."
Meanwhile, sheep mutate at the rate of 1.1 +/- 0.5 x 10
-4 mutations/gamete per locus says this :
https://genome.cshlp.org/content/6/9/876.full.pdf
Which seems a HUGE rate - aren't there ~2.6 Gb in the sheep genome ? :
http://www.livestockgenomics.csiro.au/sheep/oar3.1.php
Perhaps a more knowledgable member can help explain that.
So,
out of all that -
Sheep have certainly changed in the last two millenia.
But, it's not clear how much observable genetic change has occured in that time,
and those changes maybe swamped by the amount of variation present in the extant sheep breeds.
(Assuming too that they used sheep not goat.)
Note that the sample used was 2cm by 2cm in size, and 5cm by 5cm was mentioned somewhere.
I doubt they'll be using that method on p52
DNA testing of vellum doesn't look very useful
Kapyong