Results 1 to 9 of 9

Thread: atDNA what does 38cm signify

  1. #1
    Registered Users
    Posts
    6
    Sex

    atDNA what does 38cm signify

    In autosomal DNA what does 38cm on one segment signify. How close of a relation. I am trying to get a reference in general because my family comes from a smaller region where there was likely intermarriage between cousins back in the day so genetically may be closer than reality.

  2. The Following 2 Users Say Thank You to BlueEyedItalian For This Useful Post:

     JMcB (05-05-2021),  Nino90 (05-06-2021)

  3. #2
    Gold Class Member
    Posts
    2,827
    Sex
    Location
    Florida, USA.
    Ethnicity
    English, Scottish & Irish
    Nationality
    American
    Y-DNA (P)
    I-FT80854
    mtDNA (M)
    H1e2
    mtDNA (P)
    K1

    England Scotland Ireland Germany Bayern Italy Two Sicilies France
    Here is a website that may come in handy:

    https://dnapainter.com/tools/sharedcmv4
    Paper Trail: 42.25% English, 31.25% Scottish, 12.5% Irish, 6.25% German, 6.25% Sicilian & 1.5% French. Or: 86% British Isles, 6.25% German, 6.25% Sicilian & 1.5% French.
    LDNA(c): 86.3% British Isles (48.6% English, 37.7% Scottish & Irish), 7.8% NW Germanic, 5.9% Europe South (Aegean 3.4%, Tuscany 1.3%, Sardinia 1.1%)
    BigY 700: I1-Z140 >I-F2642 >Y1966 >Y3649 >A13241 >Y3647 >A13248 (circa 620 AD) >A13242/YSEQ (circa 765 AD) >FT80854 (circa 1650 AD).

  4. #3
    Registered Users
    Posts
    6
    Sex

    Quote Originally Posted by JMcB View Post
    Here is a website that may come in handy:

    https://dnapainter.com/tools/sharedcmv4
    Great it does. Now is there any way to identify cousins from paternal/maternal side if the parents are dead? Aside from going through the family tree... I think I read you can do something like that via gedmatch.

  5. #4
    Registered Users
    Posts
    2,603
    Ethnicity
    Northern Ireland
    Nationality
    Northern Irish
    Y-DNA (P)
    R1b-L193(BY2634)
    Y-DNA (M)
    R1b-M222

    Northern Ireland Ireland Scotland
    2nd or 3rd great grandparent shared

  6. #5
    Registered Users
    Posts
    6
    Sex

    Quote Originally Posted by Nqp15hhu View Post
    2nd or 3rd great grandparent shared
    Yet at the 2nd & 3rd great grandparents everyone is in entirely different countries. That is why I said generic isolation makes things seem closer than they are.

  7. #6
    Registered Users
    Posts
    2,603
    Ethnicity
    Northern Ireland
    Nationality
    Northern Irish
    Y-DNA (P)
    R1b-L193(BY2634)
    Y-DNA (M)
    R1b-M222

    Northern Ireland Ireland Scotland
    Quote Originally Posted by BlueEyedItalian View Post
    Yet at the 2nd & 3rd great grandparents everyone is in entirely different countries. That is why I said generic isolation makes things seem closer than they are.
    Itís not intermarriage though if itís one segment.

  8. #7
    Registered Users
    Posts
    6
    Sex

    Quote Originally Posted by Nqp15hhu View Post
    It’s not intermarriage though if it’s one segment.
    I never said it was intermarriage with this person. I am trying to figure out how far back they are related.

    It is intermarriage among my family back in the day that amplifies generic similarities beyond reality.

  9. #8
    Registered Users
    Posts
    4,210
    Sex
    Location
    Tierra de Ayllon
    Y-DNA (P)
    U152>L2>Z49>Z142>
    mtDNA (M)
    H1bt
    Y-DNA (M)
    I2a2a1b2a1b1>Y4925
    mtDNA (P)
    H37

    England Scotland Wales Germany Ireland Sweden Finns
    This website talks about largest segments and has some charts
    https://thegeneticgenealogist.com/20...hared-segment/

    The chart only goes out to a 3rd cousin twice removed (roughly the same as a 4th cousin) with a max segment size of 50cM, but, I had a 47cM segment that turned out to be a 7th cousin. This line was mostly male descendants with 2 female transmissions. Male to male and male to female (father to daughter) transmissions typically transfer larger segments when compared to female to female or female to male.
    https://anthrogenica.com/showthread....l=1#post163990
    Last edited by MitchellSince1893; 05-06-2021 at 03:07 PM.
    Y DNA line continued: Z142>Z12222>FGC12378>FGC12401>FGC12384
    37% English, 26% Scot/Ulster Scot, 14% Welsh, 14% German, 3% Ireland, 3% Nordic, 2% French/Dutch, 1% India
    Hidden Content

  10. The Following User Says Thank You to MitchellSince1893 For This Useful Post:

     JMcB (05-06-2021)

  11. #9
    Registered Users
    Posts
    2,038
    Sex
    Location
    Chicago, Illinois
    Ethnicity
    mixed European
    Nationality
    USA
    Y-DNA (P)
    Dad: R1b/L21/DF63
    mtDNA (M)
    K2b2
    Y-DNA (M)
    R1b-M269
    mtDNA (P)
    K2b1a1a

    United States of America England Wales Sweden Germany
    Quote Originally Posted by BlueEyedItalian View Post
    Great it does. Now is there any way to identify cousins from paternal/maternal side if the parents are dead? Aside from going through the family tree... I think I read you can do something like that via gedmatch.
    Yes, if you know who some of your matches are. My parents aren't on ancestry, but a known paternal first cousin is, and several second cousins. If you start with your closest matches and identify them, it will help sort out the others.

Similar Threads

  1. MyHeritage misses legit 38cM match
    By peloponnesian in forum MyHeritage
    Replies: 6
    Last Post: 02-16-2021, 07:19 PM
  2. Replies: 1
    Last Post: 03-08-2019, 06:04 PM
  3. I need help to understand an atDNA match
    By keyhook in forum Autosomal (auDNA)
    Replies: 3
    Last Post: 08-17-2018, 02:42 PM
  4. Serbian atDNA results
    By Macura in forum Southern
    Replies: 30
    Last Post: 05-22-2017, 10:48 AM
  5. How many generations back can atDNA tests truly detect?
    By A Norfolk L-M20 in forum Autosomal (auDNA)
    Replies: 21
    Last Post: 10-17-2016, 09:51 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •