Two Professional Genealogists surprised by Ancestry DNA Results
Ancestry DNA has come up with a new feature to your DNA results that we call Amount of Shared DNA. The new feature allows you to see scientific details behind your relations or connections with each of your DNA matches. You are now having access to each of your DNA samples. Look at the example below:
New DNA Matching Details
The customer shared 71 centimorgans across 5 DNA segments with this specific DNA match. Whenever you click on the info icon that appears at the right to the confidence level, on the same box, you can also click on the ‘What does this mean’ to get more information about centimorgans and how it is used to calculate relations and confidence scores for each DNA match.
How are Centimorgans calculated?
The number of shared centimorgans provides the amount of DNA that you and your match probably have in common because you both are inherited from a common ancestor. As the relations get more remote, it is important to differentiate between DNA that is the same because it was inherited from a common forefather and the DNA that is common for other reasons due to common rationality or older shared history.
The number of centimorgans we record is our evaluation of the amount of shared DNA that we can faithfully characterize to a new common ancestor instead of more remote shared history. You can share more DNA with your match and can pass it on with very small sections that are critical to characteristic to a new shared ancestor.
To identify shared DNA because of a new common ancestor, Ancestry uses cutting-edge technology called Timber that loads watching sections throughout the genome accordingly. Because close matches have shared DNA, and it reflects. There is no need to load their shared segments, so Ancestry uses only Timber for matches evaluated to be 3rd cousins or greater. It results in reported centimorgans for close DNA matches that mirrors our unweighted evaluations of the amount of DNA shared. For more remote DNA matches, the stated centimorgans mirror the weighted evaluation using Timber.
How the shared segments are calculated
Ancestry’s new feature also records the number of DNA sections that you share with any specific match. It also provides some important information from our matching algorithm. There is some practical information or details that affect this data. First, for speed and accuracy, our calculation chunks the genome up into 44 parts over 22 pairs of autosomes. This piece does not always match with the chromosomes themselves.
For example, one chromosome may be left unbroken, while another may be damaged into two or more parts. Above, where 71 centimorgans had shared over five parts, you would have a 14-cM chunk and 12-cM chunk, and a 9-cM and 15-cM chunk on segments 2 and 3 of chromosomes 8, and a 21-cM chunk on segment 1 of chromosome 18 over 71 total cMs on 5 different sections.
Second, a single section or part of DNA inherited by two persons from a new common ancestor could be shown in our calculations as many shared sections within that primarily inherited segment. This can be due to some inherent problems in chromosome phasing, IBD evaluation methods, and genotyping.
IBD stands for identical by descent and refers to sections of DNA inherited from a new ancestor. Also, the most convenient phasing pipelines have few issues with gaining a complete phase. The IBD section can swap between deduced chromosome copies and part across many identified sections.
GERMLINE is an IBD recognition algorithm that has a procedure for reducing this effect that allows matches to bounce back and ahead between chromosome copies, but it is not good at stitching these back together. It results in DNA matching algorithms that will commonly recognize two separate matches near one another that represent one long section of IBD. Ancestry does not use the number of shared sections in our relation predictions. We commonly use the total quantity of shared centimorgans, as it has proved to give more precise relationship estimates.
You also can get more details in our DNA Matching White Paper. So, when you hope to get no more than 22 shared sections with your mother, for example, you will see more both because little identified shared sections are not ever stitched with each other after when they are recognized. Even the number of shared sections can be a useful partner in your research because of the warnings we have said before. We suggest you concentrate your attention on the number of common centimorgans.
Two Professional Genealogists surprised by Ancestry DNA Results
Research generally helps in discovering distant cousins with the help of professional genealogists. It is more exciting when two genealogists find out that they are connected with one other. Crista Cowan and Nicka Smith made this discovery with Ancestry DNA. You can also listen to them by clicking on the video link https://youtu.be/xeA1wZY7X4Y.
Ancestrydna.com/activate helps you to know about your family’s journey. It lets you know from where your family came and tell about their genetic origin. Ancestry DNA simply uses your sample to find all possible information about your family’s past.
