Understanding second cousin match on AncestryDNA?

Question

I am a little confused. I have a match on Ancestry.com...who by the way doesn't answer my emails which is incredibly disappointing as he is the closest match I have ever had and I've been on FTDNA for 15 years...anyway. This is what the match says Shared DNA: 546 cM across 28 segments.

Concluded possible range 1st to 2nd cousins. This seems a little odd to me...as I am 67 and the person tested has put his age range as 18 to 29.

Answer 1

Due to the span of time over which children can be born, age doesn't have much bearing unless you're talking about direct-line relationships (parent/child, grandparent/grandchild, etc).

For example, within my own family: My great-grandmother was born in 1870, had her first child in 1885 (at age 15), my grandfather in 1906 (at age 36), and her last child in 1915 (at age 45). My second cousin from that first child is about 58 years older than me (the youngest of my second cousins are about 15 years older than me).

According to the Shared cM Project for 554 cM, these are the potential relationships and their probabilities:

• 87.24%: Great-Great-Aunt/Uncle, Half Great-Aunt/Uncle, Half 1C, 1C1R, Half Great-Niece/Nephew, Great-Great-Niece/Nephew
• 10.29%: 1C †, Great-Grandparent, Great-Aunt/Uncle, Half Aunt/Uncle, Half Niece/Nephew, Great-Niece/Nephew, Great-Grandchild
  • † this relationship has a positive probability for 546cM in thednageek's table of probabilities, but falls outside the bounds of the recorded cM range (99th percentile)
• 2.48%*: Great-Great-Great-Grandparent, GGG Aunt/Uncle, Great-Great-Great-Aunt/Uncle, Half GG-Niece/Nephew, Half GG-Aunt/Uncle, Half Great-Great-Niece/Nephew, Half Great-Great-Aunt/Uncle, Half Great-Great-Niece/Nephew, 1C2R, 2C, Half 1C1R
  • * this set of relationships has a positive probability for 546cM in thednageek's table of probabilities, but falls outside the bounds of the shared cM project (99th percentile)