Collecting Sharing Information for Known Relationships

Blaine Bettinger 57 Comments

EDIT (3/31/2015) – Beginning on April 1, 2015, I will no longer be able to accept submissions other than through the portal. My sincerest apologies, and I so greatly appreciate the files that have been submitted this way, but I have been inundated and won’t be able to take the extra time to process any non-portal submissions made after April 1, 2015. Thank you!

I need your help! I’m trying to gather data about the ranges of DNA shared by known relatives. How much DNA do you share with your sister? your brother? your second cousin? While it is possible to predict approximately how much DNA you share with a close relative, the actual numbers vary more than you might think.

If you’re interested in participating in this project, I’m looking for two numbers for the known relationship: (1) the total amount of shared DNA in cMs; and (2) the largest shared block in cMs. At Family Tree DNA, for example, you can find the numbers here: ... Click to read more!

Ancestry Set to Expand DNA Circles

Blaine Bettinger 46 Comments

AncestryDNAIn a press release – and blogger meetup – from Ancestry.com today (see “Ancestry Announces 2015 Product and Content Lineup“), AncestryDNA announced plans for the test in 2015, which includes launching the test in Australia and Canada, as well as a new way to identify ancestors using only DNA.

From Today’s Press Release:

Continued Growth for AncestryDNA

  • With a database of over 700,000 genotyped members, AncestryDNA has generated over one billion cousin connections to date. In 2015, we project this database to grow to exceed well over one million genotyped members, resulting in even more and higher quality cousin matches.
  • Following the successful launch of AncestryDNA in the UK, we will soon be bringing the service to our members in Australia and Canada, and in doing so, will connect the major English-speaking migrations and globally connect families like never before.
  • Building on DNA Circles, in 2015 we will launch a new experience that will use the latest genetic technology to discover new ancestors without the customer having to search records or build a family tree. This new feature will transform how family history research is done by providing valuable hints to help experienced genealogist looking to break through brick walls, as well as open family history to a whole new segment of the population. Through this new experience, AncestryDNA customers will be able to discover new ancestors as far back as the 1700’s by connecting into existing DNA Circles.

DNA Circles Without Family Trees

On the last point, in the coming weeks AncestryDNA will launch an extension of the DNA Circles tool in which they assign you to a DNA Circle without having a family tree connection.

Currently, you must have a decent public tree in order to be put into a DNA Circle based on genealogical relationships. Using this new tool, however, you will (potentially) be put into circles without a tree showing that you belong to the circle (in other words, based only on genetic relationships regardless of the trees). ... Click to read more!

How Do DNA Segments Get Smaller?

Blaine Bettinger 11 Comments

Many genetic genealogists, myself included, often talk about DNA segments getting “broken up” or “broken down” as they are passed from one generation to the next. But this language can be misleading, since DNA isn’t really “broken up” into pieces when it passed down; instead, a few pieces are traded between nonsister chromosomes in a process called RECOMBINATION.

Genetic recombination is a process of crossover between chromosomes during MEIOSIS (meiosis = a very specialized cell division that creates eggs and sperm for reproduction). Very early in meiosis, the cells duplicate the chromosomes. Normally, every cell has 23 pairs of chromosomes, for a total of 46 chromosomes. However, in the first step of meiosis, the chromosomes are duplicated to result in a total of 92 chromosomes. There are 4 copies of chromosome 1 (2 copies of the chromosome you got from your mother, and 2 copies of the chromosome you got from your father). There are 4 copies of chromosome 2, and so on. ... Click to read more!

Announcing the Genetic Genealogy Standards

Blaine Bettinger 12 Comments

Today, at the first annual Salt Lake Institute of Genealogy Colloquium, the final draft of the Genetic Genealogy Standards were officially announced and released!

The standards are the work of a wonderful group of people, and have been in the works for over a year (see “DNA Standards and Certification – A Response to an NGS Quarterly Editorial” and “Announcing the Creation of Genetic Genealogy Standards“). Thanks in large part to a very productive comment period in May and June of 2013 in which more than 75 comments were provided, the document has been fine-tuned and we believe it is an excellent source of guidelines.

There will be lots more to come, including guidelines for Y-DNA and mtDNA testing and interpretation, as well as some guidance for citing DNA test results in reports, scholarship, and in general. Stay Tuned! ... Click to read more!

The Most Read Posts of 2014

Blaine Bettinger

Inspired by other end-of-year posts by Denise Levenick, Judy Russell,Roberta Estes, and others, here are my Top Five Posts in 2014. This year was a turning point for genetic genealogy as it finally switched from a cottage industry to a widely accepted commercial enterprise. I can only imagine what 2015 will bring.

Here are the top 5 visited posts, ranked from highest to lowest:

1.  “A Review of AncestryDNA – Ancestry.com’s New Autosomal DNA Test” – this post from 2012 has received more comments than perhaps any other post on the blog.

2. “What Else Can I Do With My DNA Test Results?” – an extensive list of both free and paid third-party options for your DNA test results.

3. “Unlocking the Genealogical Secrets of the X Chromosome” – year after year this post is always one of the most viewed from the blog. ... Click to read more!

AncestryDNA Recreates Portions of the Genome of David Speegle and his Two Wives

Blaine Bettinger 11 Comments

GeneticGenealogyFutureStamp1UPDATE: AncestryDNA scientist Dr. Julie Granka posted about this new development at “AncestryDNA Scientists Achieve Advancement in Human Genome Reconstruction,” and here’s the YouTube video: “AncestryDNA Reconstructs Partial Genome of Person Living 200 Years Ago.”

I’ve written before about a poster presented by AncestryDNA at the American Society of Human Genetics 2013 annual meeting, entitled “Reconstruction of Ancestral Human Genomes from Genome-Wide DNA Matches,” and a poster presented at the 2014 meeting entitled “Reconstruction of ancestral human haplotypes using genetic and genealogical data.” In these posters, the scientists at AncestryDNA revealed their efforts to recreate portions of the genomes of an 18th century couple using sequencing information from hundreds of descendants. ... Click to read more!

Recreating a Grandmother’s Genome – Part 2

Blaine Bettinger 6 Comments

In my last post (see “Recreating a Grandmother’s Genome – Part 1”), I introduced my grandmother Jane, who died when I was just 8 years old. Although I have only a few memories of my grandmother, I have 25% of her DNA. To explore this rich genetic legacy, I’m trying to recreate as much of my grandmother’s genome as possible using the GEDmatch Tier 1 tool called “Lazarus.”

In the last post we also learned about the new Lazarus tool. In today’s post, we’ll choose what kits to use for my grandmother’s Lazarus kit.

Finding DNA Kits for Lazarus

GROUP 1 – DESCENDANTS ONLY

So GROUP 1 must be descendants of the target Lazarus kit. My grandmother has six children, twelve grandchildren, and eleven great-granchildren. Any of these 29 people are candidates for GROUP 1. Of those 29 people, I’ve tested four of the six children and one of the grandchildren (myself). Yeah, I know, I have more testing to do! ... Click to read more!

Recreating a Grandmother’s Genome – Part 1

Blaine Bettinger 22 Comments

My grandmother Jane died in 1984 when I was just 8 years old. I have some really great memories of her, faded with time but still filled with emotion. Bath times, spending time with her in the summer, newspaper hats, chrysanthemums.

However, in addition to those memories, she gave me a very unique genetic heritage. She was from a region of the world with a high degree of admixture, and thus it is from her that I obtained my Native American mtDNA, my Native American, African American, and Spanish autosomal DNA. It is an incredibly rich and fascinating genetic legacy.

In an attempt to learn more about my grandmother’s genetic heritage, I’m using GEDmatch’s new Lazarus tool to try to recreate as much of her genome as possible. Join me on the journey, and learn about this new tool. ... Click to read more!

Small Matching Segments – Examining Hypotheses

Blaine Bettinger 13 Comments

Last week I published “Small Matching Segments – Friend or Foe?” to join in the community’s conversation about the use of “small” segments of DNA, referring to segments 5 cM and smaller (although keep in mind that the term “small,” without a more specific definition, will mean different things to different people).

The question that the community has been struggling with is whether small segments of DNA can be used as genealogical evidence, and if so, how they can be used.

As I wrote in my post, a significant percentage of small segments are false positives, with the number at least 33% and likely much higher. In my examination and in the Durand paper I discuss, a false positive is defined as a small segment that is not shared between a child and at least one of the parents. ... Click to read more!

Small Matching Segments – Friend or Foe?

Blaine Bettinger 44 Comments

There has been a great deal of conversation in the genetic genealogy community over the past couple of weeks about the use of “small” segments of matching DNA. Typically, the term “small” refers to segments of 5 cM and smaller, although some people include segments of 7 cM or even 10 cM and smaller in the definition.

The question, essentially, is whether small segments of DNA can be used as genealogical evidence, and if so, how they can be used.

While it may seem at first that all shared segments of DNA could constitute genealogical evidence, unfortunately some small segments are IBS, creating “false positive” matches for reasons other than recent ancestry. These segments sometimes match because of lack of phasing, phasing errors, or a variety of other reasons. One thing, however, is clear: there is no debate in the genetic genealogy community that many small segments are false positive matches. There IS debate, however, regarding the rate of false positive matches, and what that means for the use of small segments as genealogical evidence. ... Click to read more!