Comparing with a known Second Cousin

[madman]

1/2 first cousins twice removed = 4TH COUSIN
first cousins twice removed = 3RD COUSIN

No objection to the term -- have been wondering what the correct term was for descendents of half-siblings.

A Census lists someone as "step-brother" of one of my great-grandparents. I am suspecting he may be half-brother -- and some of his children are still alive -- if full siblings, his children would be my first cousins twice removed -- so if 1/2 siblings, do I say 1/2 first cousins twice removed?

Anyone have any idea what relationship 1/2 first cousins twice removed should show as?? How much DNA likely shared? What "Relationship Range" they would likely be in?

And what about 1/2 first cousins once removed? (an appropriate Aunt of mine also tested) I know I saw FAQ saying there is better than (or approximately?) 99% chance that 2nd cousins will show as second cousins -- would 1/2 first cousins once removed have about the same amount of shared DNA as second cousins, with the same likelihood of it showing up, and same Relationship Range? Or ??

[S9 H9]

1/2 first cousins twice removed = 4TH COUSIN
first cousins twice removed = 3RD COUSIN

No.

A first cousin 2x removed is similar (if not identical) to a second cousin.

A half first cousin (i.e., sharing 1 grandparent, not 2 grandparents) 2x removed is similar to a half second cousin.

[tomwdcraftr]

I have now had some success in determining new family surnames. This is not with the adoptee I originally mentioned.

In both situations I found others who overlapped at a particular Chromosome, and I was able to determine a common surname in both situations.

With one circumstance, I was able to take a family line back from 1820 to 1620 and add new known surnames to my ancestry.

One other situation gave me the surname of a GGG Grandmother, and took her line back from 1820 to the early 1700s.

[tomwdcraftr]

Oops, forgot about one other find thanks to overlapping Chromosome with others. I have an ancestor of Christena Carnes, born in Kentucky about 1807. I didn't know her parentage. Those I compared with showed Carnes/Kerns/Kern as ancestor's back to Bedford County, Virginia. Low and behold, Christena's father I've found as Abraham Kerns, who works back to Beford, Virginia, with more about his ancestry.

[willy]

what means exctly the same segment ?

Hello I would like to know if somebody knows about to share
exactly the same segment with many people as this jpg attached file . is that mean something special ?


Thanks a lot

Willy

[willy]

ok nobody knows about my question

bye

[JohnG]

Hello I would like to know if somebody knows about to share
exactly the same segment with many people as this jpg attached file . is that mean something special ?


Thanks a lot

Willy

This kind of list is fairly common. I think with those short lengths it means a common origin quite a while back. I have figured one of these out and the common ancestor was born in 1700s and had children who settled both the US and Canada. Somehow, even today, many of us have that 8 cM trade mark. My luck in this case was a surname that was shared by three of the list. Two have figured out exactly how they descend, I am closing the gap (and the common ancestor its a family story and family first name), and others are anywhere from puzzled to having working theories.