Why DNA Painter the game
In March the free website DNA Painter won an award at the genealogy show RootsTech. Debbie Kennett explains why it deserves its success
DNA Painter is an easy-touse website for mapping out your chromosomes and identifying which segments you’ve inherited from specific ancestors. It’s proving a popular resource for family historians. There’s a DNA Painter User Group, a Facebook group with over 5,000 members, and a fan base of more than 10,000 users – and the website won the Grand Prize in the DNA Innovation Contest, held at RootsTech 2018 in Utah in March. DNA Painter ( dnapainter.
com) also has a very useful tool that allows you to enter the amount of DNA you share with a match and output a list of the possible relationships along with the probabilities (see the box below). But how does it work?
DNA for beginners
Our DNA is packaged up into chromosomes which are the basic building blocks of life. We inherit 23 pairs of chromosomes from our parents – one set from our mother, and one set from our father. Two of those chromosomes are the sex chromosomes. If you are a male then you have an X-chromosome inherited from your mother and a Y-chromosome inherited from your father. However, if you are female then you have two X-chromosomes – one from each of your parents.
The autosomal chromosomes – the 22 pairs that aren’t sex chromosomes – undergo a process of recombination so that they are chopped up and shuffled around before being passed on. This means that the DNA you inherit from your parents is a patchwork of the DNA you’ve inherited from your grandparents, your great grandparents and your more distant ancestors.
We share large segments of DNA with our close cousins, but we are likely to share just a single segment with a fifth or sixth cousin – assuming we share any DNA with them at all. The amount of DNA we share with our matches is measured in units known as centiMorgans (abbreviation ‘cM’).
Chromosome mapping is the process of assigning DNA segments to specific ancestors. If you have a match with a maternal second cousin, you will know that your shared segments of DNA have all been inherited from your mutual great grandparents. A match with a paternal first cousin will allow you to assign those segments to your paternal grandparents.
It’s like doing a big jigsaw puzzle. As you slot more and more segments into your chromosome map, it becomes easier to connect with new matches and work out where they fit on your
tree. Chromosome mapping works best when you work from the known to the unknown. It therefore helps to test as many close relatives as possible.
Chromosome mapping is a fun way to learn about genetics and understand the process of recombination. If enough descendants from a specific ancestral couple have been tested, it’s even possible to reconstruct much of their ancestral genomes. In the future this will allow us to make inferences about the appearance of our ancestors such as the colour of their hair and their eyes, and perhaps identify where specific traits originated.
Unfortunately chromosome mapping has traditionally been performed using complicated spreadsheets, and was something that only advanced genealogists had the time or ability to do. DNA Painter now makes the process much easier. You simply copy and paste the segment data into the program, and it paints the chromosomes for you onto a colourful map. You can click on the map to add, edit or delete items, or to change the colours assigned to the segments.
Jonny Perl, the London-based web developer who created DNA Painter, describes it as “a painting you keep going back to and touching up”, adding that it is about the “unknown as well as the known”. You can experiment with different relationships, and hypothesise in a safe way because you’re not publishing the information for anyone else to look at.
The right kind of data
In order to start chromosome mapping, you need to have access to the matching segment data. Family Tree DNA ( familytreedna.com), MyHeritage ( myheritage.com) and 23andMe ( 23andme.com) all provide segment data. AncestryDNA ( ancestrydna.
co.uk) does not, but you can download your raw data from AncestryDNA and upload it to Family Tree DNA and MyHeritage, and encourage your matches to do the same. You will need to pay a fee of $19 to access Family Tree DNA’s Chromosome Browser feature and segment data. You can also access segment data by uploading your DNA to the free third-party database GEDmatch ( gedmatch.com). Note that GEDmatch is a very ‘open’ website and its data isn’t just used for genealogy; indeed a recent story on the Who Do You Think You Are? Magazine website discussed US police identifying a suspected serial killer from DNA matches on GEDmatch ( bit.ly/killer
dna). However, you can create research kits and share privately, without participating in the open database.
Humble origins
Jonny has been researching his family tree for over 10 years. He was initially sceptical about DNA testing, but eventually took the test in December 2016. After getting the results, he tried to create chromosome maps in a spreadsheet to make sense of his matches, but he soon realised that he wanted a better and more visual system. He shared an early version of DNA Painter with a Facebook group for people interested in using DNA for genealogy in July 2017.
It became clear that there was a real need for such a service, but not everyone understood what he was trying to do. So Jonny continued to develop the tool – he previously had his own digital agency, so was used to making websites as intuitive as possible. Two months later Jonny made a casual mention of DNA Painter in response to an enquiry in another Facebook group. He received an enthusiastic response, and the tool took off through word of mouth.
Next steps
The Grand Prize in the DNA Innovation Contest, which was arranged by a nonprofit organisation called Grow Utah, amounted to $15,000, plus consultancy worth $10,000; this will allow Jonny to convert the site into a business. DNA Painter is currently free to use, but he will launch a premium service with improved functionality.
Jonny is already building a number of new tools. A bulk-import feature will allow you to assemble groups of matches in a spreadsheet and import them all in one go, or even import an entire match list. He’s also working on a way to include simple family trees, and is creating an interactive double-fan chart. Another project in the pipeline is a tool to help with visual phasing. This complicated process involves using three or more siblings to assign segments to specific grandparents. Although visual phasing can be done in Excel or PowerPoint, it’s crying out for a simpler solution. Jonny admits that creating DNA Painter has been a learning curve, combining his passion for genetic genealogy with his talent for web design. “I’m on a path here. I really wanted to build the website for myself, but other people liked it and so I polished it up a bit. Then more people liked it, and now it’s become really popular!” Debbie Kennett is the author of DNA and Social Networking (The History Press, 2011)