Ancient DNA

Discussion of everything related to the Theory of Evolution.

Moderators: Leonid, amiradm, BioTeam

Post Reply
HELISA
Death Adder
Death Adder
Posts: 67
Joined: Sat Feb 25, 2006 12:55 am
Location: Illinois

Ancient DNA

Post by HELISA » Tue Apr 11, 2006 7:22 pm

Does somebody know how to verify the results obtained from analysis of ancient DNA?
As far as I know, when I have the DNA sequence extracted from ancient speciment, to make sure that it is not contaminated with "modern" DNA I would blast this sequence to find out if it shows similarity with sequences from related organism. What other ways can I use to do that?
My another question concerns the major problem of "ancient DNA" studies, why this research has a great burden of proof than "modern DNA" studies?
Is this just because the ancient DNA could be easily contaminated with other DNA or because it is very degradated and it is hard to use it for molecular studies?
I would be very grateful for any suggestions or links...
Image
Image

HELISA
Death Adder
Death Adder
Posts: 67
Joined: Sat Feb 25, 2006 12:55 am
Location: Illinois

Help please..

Post by HELISA » Wed Apr 12, 2006 12:59 pm

hmm..nobody answers my questions, so I will try to construct them differently...
I am asking about the ways of verifing that I've found and sequenced ancient DNA. I need to have a confidence that I have a real ancient DNA not for instance some "crap" from the air.
What is more, I am expecting that I have the mamooth sequence, but unfortuantelly near my fossils some other animals also died...so I need to confirm that this what I have in my tube is actually mammoth DNA.
Also I need to verify the quality of DNA before I'll star working with it.
How to estimate it?
And at the end...the last question: why the research of ancient DNA has a great burden of proof than "modern DNA" studies.
So...any ideas?
Image
Image

User avatar
Linn
King Cobra
King Cobra
Posts: 1735
Joined: Sun Jan 22, 2006 3:53 am
Location: Massachusetts, USA

Post by Linn » Wed Apr 12, 2006 3:56 pm

Hi,
I do not know much about this subject except
what I have read.
But I do believe they have mammoth dna.
and it is close to elephant dna
so if an other animal died nearby you should be
able to see enough difference in sequence.
"How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in life you will have been all of these".

~ George washington Carver

HELISA
Death Adder
Death Adder
Posts: 67
Joined: Sat Feb 25, 2006 12:55 am
Location: Illinois

The only way?

Post by HELISA » Thu Apr 13, 2006 12:50 pm

So, the only way to verify that my ancient DNA is authentic is to align it with homologous sequences from modern species?
Image
Image

User avatar
mith
Inland Taipan
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN
Contact:

Post by mith » Thu Apr 13, 2006 12:55 pm

Can't you compare it to another mammoth sequence?
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

HELISA
Death Adder
Death Adder
Posts: 67
Joined: Sat Feb 25, 2006 12:55 am
Location: Illinois

It is not so easy...

Post by HELISA » Thu Apr 13, 2006 3:09 pm

The study of ancient DNA are subject to various difficulties i.e. the post mortem degradation of DNA, the problem of contamination from exogenous source of DNA, PCR artifact. So how you can be sure that the ancient sequence which you are going to use to compare it to your sequence is authentic?
Image
Image

User avatar
mith
Inland Taipan
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN
Contact:

Post by mith » Thu Apr 13, 2006 9:39 pm

you won't know for sure so you could compare it to quite a few different samples, but I think it's highly unprobable that they would all be contaminated the same way...
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

User avatar
damien james
Coral
Coral
Posts: 237
Joined: Thu Mar 02, 2006 5:51 am
Location: U.S.

Post by damien james » Fri Apr 14, 2006 1:40 am

I think it matters how ancient. The insides of cell do not fossilize to produce DNA, so if your mammoth is fossilized, you cannot sequence genome. If it was frozen then maybe. Also, out of curiosity, what equipment are using for sequencing?
The hand of God may well be all around us, but it is not, nor can it be, the task of science to dust for fingerprints.

2810712
King Cobra
King Cobra
Posts: 697
Joined: Thu Jan 20, 2005 12:19 pm

Post by 2810712 » Tue Apr 18, 2006 2:52 pm

mithrilhack wrote:you won't know for sure so you could compare it to quite a few different samples, but I think it's highly unprobable that they would all be contaminated the same way...


If the probability is less then u can see for the constant part as the source of the DNA to be compared... but see you highly get one memmoth! & if u get many & that too differently contaminated, its likely that those samples are of different 'stains' of mammoth...so they may be differing even without contamination. If u use just the constant part as mammoth DNA, but u'll lack accuracy as just few inherent mutations corrospond to many years...

U can at a time use both DNA & protein to compare...but proteins are less safe in most cases i think...so this may lead to wrong conclusions...


hrushikesh

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest