Concepts – Identical by…Descent, State, Population and Chance

In genetic genealogy, what does it mean when someone says they are “identical by” something…and what are those various somethings? In autosomal DNA, where your DNA on chromosomes 1-22 (and sometimes X) is compared to other people for matches of … Continue reading

Concepts – How Your Autosomal DNA Identifies Your Ancestors

Welcome to the concepts articles. This series presents the concepts of genetic genealogy, not the details.  I have written a lot of detailed articles, and I’ve linked to them for those of you who want more.  My suggestion would be … Continue reading

What’s the Difference Between Pedigree Collapse and Endogamy?

There has been recent discussion and confusion about the difference between pedigree collapse and endogamy. Let’s take a look at the similarities and differences and what it means to genealogists. Pedigree Collapse Pedigree collapse occurs when the same person/people appear … Continue reading

Nine Years and Future Plans – Happy Blogiversary

Happy Blogiversary! Yes, blogiversary is actually a real word for a blog’s birthday. It’s DNAeXplained’s 9th birthday and I nearly forgot. How could I??? What do you get a blog for its birthday anyway? History and Changes I remember the … Continue reading

What is a Heteroplasmy and Why Do I Care?

Most people have never heard of a heteroplasmy – but you might have one. You Might Have a Heteroplasmy If… …You have no exact matches at the full sequence mitochondrial DNA level. A heteroplasmy is one of the first things … Continue reading

A Triangulation Checklist Born From the Question; “Why NOT Use Close Relatives for Triangulation?”

One of my readers asked why we don’t use close relatives for triangulation. This is a great question because not using close relatives for triangulation seems counter-intuitive. I used to ask my kids and eventually my students and customers if … Continue reading

How to Download Your DNA Matching Segment Data and Why You Should

There are two or three types of data that testers may be able to download from DNA testing sites. Genealogy customers need to periodically download as much as possible. Raw data files needed for transferring DNA files from the company … Continue reading

23andMe Changes: Triangulation Doesn’t Work the Same Way

23andMe made a significant change about the time I was recording my RootsTech presentation about triangulation which provided examples at each vendor. Unfortunately, there was no notification to customers, so most people still aren’t aware. In the fall and winter … Continue reading