Margo stated that Ancestry host 100 million family trees, and that they "will soon have more than 15 million people" in their DNA network, making it the largest consumer DNA database in the world.
Crista Cowan provided a live demonstration of the new tools in her presentation "What you don't know about Ancestry". The recording of her talk is now available on the Rootstech website and is well worth watching if you want to get a good overview of the new features. I also recommend watching Diahan Southard's talk on Connecting your DNA matches, which shows how to use the tools to form genetic networks, but also highlights some of the limitations.
The Tree Tags and New and Improved Matches are currently in beta testing. You can opt in to the beta by accessing the new AncestryLab menu on your Ancestry account. This can be found under the Extras tab. ThruLines has been rolled out to the entire AncestryDNA database and you will see the feature when you log into your DNA account. The screenshot below shows what my home page now looks like.
The new matches experience replicates the functionality of the third-party Chrome extensions MedBetter DNA and DNA Match Labelling, which many of us found very helpful for managing our matches. These extensions are now redundant. If you have previously used the extensions you need to be aware that they won't work with the new system. Before participating in the beta you might want to make a note of all your groupings and tags so that you can transfer them to the new interface.
Because these new tools are all in beta testing it's important to remember that the features may change and new functionality might be added. If you spot any bugs or have suggestions for improving the tools make sure you submit feedback to Ancestry.
So now let's have a look at the Improved Matches and ThruLines features and see how they work in practice.
New and improved DNA matches
I currently have 24,900 matches at AncestryDNA, which is far more than I could ever possibly hope to investigate. Any tools that will help me to sort and filter these matches to find the most useful ones are always going to be welcome. Below is a screenshot of my new matches page. I've tested both my parents and matches are now allocated to the father's side and the mother's side. However, the parental sides are only shown for my 162 fourth cousin and closer matches. It would be really helpful if Ancestry could extend this tool to show the sides for the more distant matches, or at least for the first 1000 or 2000 matches on your match list. You will also notice that the amount of shared cM has been round up to the nearest whole number.
I always write fastidious notes about my matches and the notes can now be viewed directly from the matches page without having to click through to view the match. This functionality was previously only available when using the MedBetter DNA extension. You won't be able to see the full note on the matches page, but you can click on the note symbol, as in the screenshot above, to read the full text.
Previously we could view 50 matches on a page. Now there is an infinite scroll system which means that you can keep scrolling down the page and see more and more matches. This is very handy if you're trying to search by keyword for particular matches. I can now, for example, see all my fourth cousin and closer matches on a single page. Previously you could use the page numbers to work out how many pages of matches you had, which then allowed you to calculate the total number of matches. I can't currently see any way of replicating this function with the new system.(*See the update at the end of this article.) If you want to know how many matches you have you can use the DNAGedcom Client to download your entire match list. The Client is available for a modest subscription from DNAGedcom.
The updated match list has a number of new filters for sorting your matches. You can sort by close matches, distant matches, matches you haven't viewed, matches with notes, matches you've messaged and tree status (private linked trees, public linked trees and unlinked trees). Unfortunately the facility to filter matches by sub-region has temporarily been lost but I understand that it will eventually be restored.
The good news is that it's now possible to create custom groups which can be labelled and assigned a colour. This new feature is modelled very closely on the DNA Match Labelling extension, but provides additional functionality such as the ability to filter matches by custom group. You can also have more than one coloured dot for each match. There are 24 different colours available. I'm still experimenting with the coloured dots but an obvious use of the custom groups is to assign different colours to specific surnames or ancestral couples.
I've added a coloured dot for matches which don't have any shared matches. I can use this filter to go back and check these matches from time to time to see if they do now have any shared matches. Currently 23 of my 162 fourth cousins or closer (14%) don't have any shared matches. It will be interesting to see if the percentage drops over time as more matches start to come in.
I also have a coloured dot for what I call "dodgy matches". These are matches which share substantially less DNA with my parents than they do with me and are therefore not likely to be worth pursuing. Currently 29 of my 162 fourth cousin or closer matches (18%) fall into this dodgy category. In some cases there is a discrepancy of 10 cM or more. One match appears to share 22.3 cM with me but shares just 6.5 cM with my dad. Two of my dodgy matches actually share small amounts of DNA with both of my parents. One appears to share a single 21.2 cM segment with me but this is actually two segments: a 7.8 cM segment shared with my mum and a 6.5 cM segment shared with my dad. My second double-sided match shares 20.1 cM across 2 segments with me but this translates into a 6.1 cM segment shared with my mum and an 11.9 cM segment shared with my dad. I've not found any genealogical connection between my mum and dad within the last 400 years and these double matches are likely to be signals of very distant sharing dating back hundreds of years.
The screenshot below shows some of the custom groups I've started to use. No doubt my system will evolve over time. The coloured dots currently sort alphabetically so I might at some point decide to introduce a numbering system to get them to sort in a particular order.
AncestryDNA's shared ancestor hints, otherwise known as shaky leaf hints, have now been renamed as common ancestors. I previously only ever had six shared ancestor hints and two of those were with my parents. I now have 20 common ancestors, though again two of those are with my parents. The shaky leaf hints only used our family tree and the trees of our matches to identify a shared ancestor. The common ancestors feature compares family trees and then deploys the power of other people's family trees to try and identify the common ancestor. The common ancestor feature is a useful tool to guide your research but every link will need to be carefully checked, and extreme caution needs to be exercised when matches are identified with more distant cousins.
Below is an example of a predicted common ancestor with a half sixth cousin. Ancestry have used my tree and my cousin's tree and then used a third-party tree to link the two lines together. Tidbury is indeed a name which appears in my family tree. The surname is concentrated in Berkshire and Hampshire and it's quite likely that I share a genealogical relationship with this match. However, the Tidburys are on my mother's side and this cousin matches me through my father so there is clearly no genetic connection. Even if the genetic connection was real, the total amount of DNA shared is very small and there is currently no way of assigning a single small segment like this to a sixth cousin with confidence.
ThruLines
ThruLines is a replacement for DNA Circles. The DNA Circles feature will continue in parallel to ThruLines for now but is no longer going to be updated. While DNA Circles was an interesting concept, in practice it was only of use to a subset of the AncestryDNA database because of the strict requirements needed to create a circle. I only ever had one DNA Circle, but AncestryDNA have identified 57 potential ancestors for me with the ThruLines feature.
ThruLines is now in open beta testing and any Ancestry member who meets the following criteria will receive the feature free of charge for a limited time:
- Your AncestryDNA results must be linked to a public or private searchable family tree.
- You must have DNA matches who have also linked their results to a public or private indexed family tree.
- Your linked family tree needs to be well built out. It should be 3-4 generations deep to have the best chance of ThruLines finding new discoveries for you to explore
With ThruLines you get a DNA record card for each ancestor for whom you have a DNA match. If you click on the card you will get a report showing the possible pathways through which you and your matches are connected to the ancestor. The pathways are filled in not just from your own family tree or the family trees of your matches but from multiple Ancestry family trees. This is essentially a machine-learning algorithm deploying the power of big data to make connections. I would guess that, like the We're Related App, the feature is generated by the AncestryDNA Big Tree. For information about the Big Tree I recommend reading the very informative blog post by Randy Seaver "Is there really an Ancestry.com Big Tree?"
You can filter the ThruLines in three ways.
- If you filter by ancestors from your linked tree you will be given descendant reports on your matches who meet the required criteria and who share the ancestors featured in your tree. This is a very useful way of locating matches who descend from a specific ancestor.
- If you filter by potential ancestors you will be able to view links that Ancestry have made between you and your matches by stitching together multiple family trees to make connections.
- The third option is all ancestors which will show you all your potential ancestors and all ancestors from your linked tree.
The example belows show a genetic descendancy report for my great-great-great-grandfather Samuel Trask. It shows my line of descent on the left and then the lines of three of my matches and their lines of descent down to the present day with the speculative links highlighted with dotted boxes. In this particular case the connections were hard to make because these matches were related to me through a female line. I hadn't noted these changes of surname upon marriage in my family tree so I might not have spotted these connections easily without this feature. However, caution will need to be exercised and the trees of these matches will need to be evaluated independently. I will also have to check the amount of shared DNA to see if it is consistent with the hypothesised relationships.
The example below shows a potential ancestor that Ancestry have identified for my great-great-great-grandfather Thomas Thorn. Two cousins who are potentially related to me through Thomas Thorn are shown, and Ancestry have also identified William Thorn as Thomas's possible father because of a DNA connection through Robert Browning Thorne. I have insufficient evidence at present to evaluate this possible link but it may be that I will get more matches on these lines in future which will provide further clues.
One disadvantage of the ThruLines is that the potential ancestor feature is triggered even if your only DNA match is with a parent. As I've tested both of my parents I'm finding that a lot of the potential ancestors are only appearing because of a single parental match. Ideally parents should be excluded from the feature or there should be the ability to filter out matches with parents.
The feature seems to be most useful for identifying how you are connected to your DNA matches. It's particularly helpful for the fifth to eighth cousin matches which are otherwise very difficult to search. In many cases the matches only share very small amounts of DNA under 10 cM and I'm not convinced that the DNA match is a result of the documented genealogical connection. Nevertheless, it's still useful to identify more genealogical cousins and to have the opportunity to communicate with them about our shared surnames and family trees.
A nifty bonus feature of the Improved DNA Matches and the ThruLines is that you can now generate a table showing the possible relationships and the probabilities of those different relationships. This is very similar to the Shared cM Tool on the DNA Painter website. The DNA Painter tool uses probabilities based on simulated data from the AncestryDNA Matching White Paper combined with ranges derived from the Shared cM Project. These new tables from Ancestry are based on simulations. They've not released any details but I'm hoping that they will publish a white paper or blog explaining the methodology behind their calculations. You can access the probabilities table from your new matches page by clicking on the question mark next to the amount of shared DNA. You can access the tool from the ThruLines feature by clicking on the amount of DNA you share with your matches in the descendancy chart.
Here is the probability table from Ancestry for one of my second cousins with whom I share 168 cM.
If I plug the amount of shared DNA (168 cM) into the Shared cM Tool at DNA Painter I get the following probability table which suggests that this cousin is slightly more likely to be a half second cousin than a full second cousin but still has a reasonable probability of being a second cousin.
This prediction is actually in conflict with Ancestry's confidence scores. Matches sharing 6-16 cM are classified as moderate confidence matches with only a 15-50% chance of sharing a single recent common ancestor. Ancestry say that for moderate confidence matches "You and your match might share DNA because of a recent common ancestor or couple, share DNA from very distant ancestors, or you might not be related."
Two separate studies have also shown that 10 cM segments can potentially go back a long way and can perhaps date back twenty or thirty generations. A chart from a 2012 study by Speed and Balding reproduced in the ISOGG Wiki shows that less than 40% of 10 cM segments are likely to fall within the last 10 generations. The Speed and Balding paper used computer simulations. A 2013 study from Ralph and Coop, using real life data from the European POPRES dataset, showed that while most 10 cM segments are likely to come from the last 500 years, we have many more very distant cousins so the vast majority of 10 cM segments will be shared through very distant ancestors. The authors go on to say that "the typical age of a 10 cM block shared by two individuals from the United Kingdom is between 32 and 52 generations". The distribution will vary depending on a given population's shared history.
I would suggest that Ancestry need to refine the parameters of their simulations to allow for more distant sharing and to produce more realistic probability tables for matches sharing low amounts of DNA. In the meantime, when weighing up the strength of DNA evidence, you need to bear in mind the uncertainties in the predictions when sharing small amounts of DNA. If you share a single 10 cM segment with a cousin there is currently no way of determining whether you are matching as sixth cousins or sixteenth cousins.
Conclusion
These new features from Ancestry are very welcome. The new matching interface is already making it much easier to navigate and sort our matches. ThruLines is likely to be a valuable tool for identifying potentially interesting matches to follow up. The predictions are likely to get better over time as more data becomes available and as the machine learning improves. Remember that any tool has to be used carefully. It provides clues but does not give you all the answers. You will still need to evaluate the DNA evidence in combination with the genealogical evidence.
Update 7th March 2019
Check out the All Matches filter in your new match list. AncestryDNA have now included stats on the total number of matches, the number of close and distant matches, the number of new matches and matches shared with your mother or father. I now have 25,089 matches, 166 of which are predicted to be fourth cousins or closer.
Further reading and resources
- Ancestry announces coveted content releases and new, game-changing family history research tools at RootsTech 2019 (Ancestry press release)
- AncestryDNA ThruLines (Ancestry Support article)
2 comments:
Glad to have your detailed take on Ancestry’s new tools, Debbie.
Many thanks. Glad you liked it.
Post a Comment