Loading ...
Sorry, an error occurred while loading the content.

Re: [I-M223] Re: SNP Primers

Expand Messages
  • Dora Smith
    That s correct as far as it goes. Groups of STR markers are used to discern if two male lineages match. Y DNA SNP s are usually one to five thousand years
    Message 1 of 8 , Jun 3, 2012
    • 0 Attachment
      That's correct as far as it goes.   Groups of STR markers are used to discern if two male lineages match.    Y DNA SNP's are usually one to five thousand years old and can discern a group that shares a common geographical origin.  

      Dora


      On 6/3/2012 4:38 PM, Emil wrote:
       



      As I understand it, an SNP refers to a single mutation (single nucleotide polymorphism) and an STR (short tandem repeat) refers to a string of repeating values as opposed to a single mutation. The number assigned to the marker for the STR is the number of times a given sequence repeats. But, I'd like to see more clarification on this as well, because I'm not sure if my understanding is correct, either.
      Emil

      --- In I-M223@yahoogroups.com, "Wilson, Eric" <eric@...> wrote:
      >
      > Hi Dora, Et. al.;
      >
      > This is some great reading, but I'm afraid some of the DNA explanation
      > seemed to contradict it's self, at least to me anyway. Maybe someone can
      > explain it to me.
      >
      > For example: On the page
      > http://freepages.genealogy.rootsweb.ancestry.com/~villandra/McKinstry/STR_Markers.html
      > It conveys that the STRs are the DYS markers and their respective values
      > used to determine Haplogroup, e.g. [ The STRs are the pieces of DNA that
      > mutate at specific DYS points to cause variation.] and thus be identifiable
      > and classifiable. Is this interpretation correct?
      >
      > Then, on the page;
      > http://freepages.genealogy.rootsweb.ancestry.com/~villandra/McKinstry/SNP_Mutations.htm
      > I interpret it to mean that the *value *found at the marker has changed.
      > Is this correct?
      >
      >
      > So as I understand it, the difference between STR and SNP, is:
      >
      > STR *only *describes the number of repeats / iterations of the *same *value
      > at a specific DYS, while
      > SNP *only *describes the *change *of an expected *value *[CGTACGTACGTA to
      > TACGTAGCTACG] but it is not a DYS ??
      >
      > Am I starting to get this, or am I still way off?
      >
      > If I'm remotely correct, then
      > A.) if DYSes are somewhat well defined, then who, where, what holds the
      > map of which DYS groups and their respective values make up a specific
      > Haplogroup?
      >
      > B.) Is there a similar way to compare SNPs like we can compare DYS changes
      > [e.g. A kit's DYS is fairly widely available from FTDNA project groups and
      > Ysearch profiles, but SNP comparisons are not]?
      >
      >
      > I'm an old school Comp Sci guy - so I feel much more comforatable with only
      > ones and zeros, so I appreciate everyone's help in leading me through this
      > scary non-binary world of DNA.
      >
      >
      >
      > Cheers;
      >
      > E!
      >
      >
      >
      > On Sat, Jun 2, 2012 at 6:16 PM, Dora Smith <tiggernut24@...> wrote:
      >
      > > **
      > >
      > >
      > > I have some information on my McKinstry project pages at
      > > http://freepages.genealogy.rootsweb.ancestry.com/~villandra/McKinstry/Intro.html
      > >
      > > DYS markers aren't SNP's, but the ones Aaron suggested may have values
      > > that are typical of a particular clade. On my McKinstry pages I get into,
      > > for instance, null DYS 425; it's an STR value that goes along with the SNP
      > > M284 100% of the time so far as is known. No scientific reason why that
      > > should be the case. Probably the whole thing is the result of a founder
      > > effect, where one ancestor with several changes in his Y DNA became the
      > > ancestor of the entire clade.
      > >
      > > Dora
      > >
      > > On 6/2/2012 6:05 PM, Eric Wilson wrote:
      > >
      > >
      > >
      > > Hey all,
      > >
      > > Are there any good rudimentary primers for the SNP concepts?
      > >
      > > Or good documentation for how to use y-search to more effect?
      > >
      > > For example, Aaron suggested a new profile with specific only certain
      > > specific DYS. His suggestion came up with some very interesting, very
      > > different results.
      > >
      > > Are there docs to help me understand his choices, suggestions and why?
      > >
      > > I really want to know more....
      > >
      > > Thanks guys,
      > >
      > > E!
      > >
      > > Sent from my iPad
      > > - please excuse the typos.
      > >
      > >
      > >
      >
      >
      >
      > --
      >
      > Cheers;
      >
      > E!
      >

    Your message has been successfully submitted and would be delivered to recipients shortly.