Yearly Archives: 2011

FamilyTreeDNA 2011 Holiday Sale

I’ve discussed genetic genealogy a few times before (in this introduction to a previous sale, and in an article on Y-DNA and mtDNA). If you’ve been interested in trying it out, you can take advantage of FamilyTreeDNA’s Holiday Sale through the end of December. Examples of price reductions include:

Y-DNA37 for $119 instead of $169 ($50 off) – men only
Y-DNA67 for $199 instead of $268 ($69 off) – men only

mtDNAFullSequence for $239 instead of $299 ($60 off) – men and women

FamilyFinder for $199 instead of $289 ($90 off) – men and women

FamilyFinder + Y-DNA37 for $318 instead of $438 ($120 off) – men only
FamilyFinder + mtDNAPlus for $318 instead of $428 ($120 off) – men and women
FamilyFinder + mtDNAFullSequence for $435 instead of $559 ($124 off) – men and women

SuperDNA (Y-DNA67 + mtDNAFullSequence) for $438 instead of $548 ($110 off) – men only
Comprehensive Genome (SuperDNA + FamilyFinder) for $627 instead of $837 ($210 off) – men only

No special coupon is needed. Just go to the Products page and the price reductions should already be shown.

If you’ve successfully used DNA testing to further your genealogy research, post about it in the comments.

Tying together my last two posts

Two posts earlier, I launched into a discussion on the future of eBooks based on my interest in reading the book Ancestors and Relatives: Genealogy, Identity, and Community by Eviatar Zerubavel, and if it made sense at this stage to get it as an eBook, or whether I should order it by mail.

My last post was about how we are connected to our relatives, both physically (objectively) and how we perceive ourselves to be related. How close is a first cousin once removed compared to a second cousin? Can we come up with an objective measure of such relatedness, or are such measures inherently subjective?

Now an article published yesterday contains an excerpt of the book mentioned in the first post that goes into detail on the topic I brought up in my second post. The article, published in Salon, is called Why do we care about our ancestors? and discusses how our perception of our ancestry in many ways helps define our perception of ourselves. An interesting read, it makes me look forward to reading the full book when it arrives.

Perceptions of Relationship

In a project I’m working on I have been giving some thought to how we relate to others, but also how we perceive we relate to others. These are not necessarily the same. Certainly it’s possible to be closer socially with cousins that are more distantly related than other cousins, but that’s a choice. What I am thinking about is how we actually perceive we are related to others, and are we right? How would we judge that in any case?

I’m sure many of you are familiar with the traditional ‘cousin calculator’ chart, such the the one below (click to enlarge):

Traditional Cousin Calculator Chart

For those of you unfamiliar with how a cousin calculator works, you take two people and determine their common ancestor. You move in one direction (i.e. along the top) from the common ancestor until you reach the relationship of the first person to the common ancestor. You then move in the other direction (i.e. down along the side) until you reach the relationship of the second person to the common ancestor. The box where those two lines merge is the relationship between the two people. For example, if you are the great-grandchild and someone else is the grandchild of a common ancestor, you move along the top to the third column for great-grandchild, and down to the second row for the grandchild, and the box that is in the 3rd column and the second row is 1st Cousin, Once Removed.

If you take a close look, you’ll notice I’ve color-coded the chart how I think we normally perceive relationships. Essentially, our sibling and parents are one degree away, our nieces/nephews and 1st cousins are two degrees away, and so forth. A second cousin is generally perceived as one degree further away from us than a first cousin. A first cousin, once removed is, at least to me, in the same category as a second cousin, and that’s what this chart shows.

Now how can we actually determine how closely we’re related? One simple method is by how much DNA we share. If we add in the percentage of DNA present between any two relatives to the chart it looks a bit different (click to enlarge):

DNA Cousin Calculator Chart

Note in the above chart that I’ve changed the color coding to match the percentages of shared DNA. The colors no long take a box shape around the common ancestor, but instead move out in the straight line. What we can see by looking at the numbers is that actually the degree of relationship is moving twice as fast as we perceived before. From a first cousin to a second cousin, the amount of shared DNA is one quarter, not one half. We perceive the second cousin as being twice as distant a relative as a first cousin, but from the perspective of DNA, they are actually four times as distant!

I know one of my 5th cousins, and we share just 0.049% DNA. That’s a half of a tenth of a percent. Not very much. Anyways, this was just an attempt to create some kind of objective view of family relationships. Of course, nothing having to do with family is really objective, right?