For every DNA Match, cM Explainer™ predicts the possible relationships between the two people and the respective probabilities of each relationship, estimates who their most recent common ancestor(s) could be, and displays a diagram showing their relationship path.
cM Explainer™ was developed by MyHeritage in collaboration with Larry Jones, developer of the cM Solver technology. We exclusively licensed this technology from Jones, and our Science team enhanced it further over a period of five months to create an industry-leading solution for genetic genealogy that is exclusive to MyHeritage. Among the enhancements are an age algorithm developed by MyHeritage’s Science team that greatly enhances the prediction by adjusting the probability of each possible relationship, and a slick user interface that displays possible relationships and their probabilities. cM Explainer™ includes useful features such as the ability to filter the predictions by full and half relationships, and to display the probable most recent common ancestor(s) (MRCA) of a match.
Using cM Explainer™ for MyHeritage DNA Matches
The page lists all your DNA Matches. Each DNA Match card shows one or more probable relationships between you and a match. This replaces the broader range of “Estimated relationships” that previously appeared.
To obtain more information on a probable relationship, click it (for example, the relationship marked with a green rectangle in the above screenshot). A popup will appear displaying all possible relationships estimated by MyHeritage, and their respective probabilities.
The probable relationship indicates how the match is related to you. If it says “Aunt”, this means the match is your aunt, not that you are the aunt of the match.
More information on possible relationships appears on the Review DNA Match page. To get there, click the “Review DNA Match” button (marked with a red rectangle in the above screenshot of the DNA Match list).
A new section was added to the Review DNA Match page, called “Possible relationships”. It shows how this person who is your DNA Match might be related to you, together with the probability for each relationship and the likely Most Recent Common Ancestor(s). This term, often abbreviated to MRCA, is the closest shared ancestor from whom you and your DNA Match are directly descended. This could be a single ancestor or a pair, depending how the match is related to you. In a full relationship the MRCA will be a pair of ancestors, and in a half relationship, it will be a single ancestor. For example, with a full first cousin, your MRCA are your grandfather and grandmother. But with a half sibling, your MRCA is one of your parents, not both.
The list of possible relationships displays the top 4 relationships, listed in descending order based on their probabilities. Click “Show more relationships plus diagram” to view other possible relationships having lower probability, as well as a diagram that shows the paths to those possible relationships.
The diagram of possible relationships displays the relationship paths to the DNA Match, along with the probability for each relationship.
Use the drop-down on the top right to have the diagram to show full relationships, half relationships, or all relationships. This ability is unique to MyHeritage, and allows you to focus on specific relationship types.
The reason we provided this selector is to simplify the diagram. The probabilities always add up to 100%, but if you are viewing only full relationships or only half relationships, some of the possible relationships may not be displayed and the probabilities shown will add up to less than 100%.
In the example shown above, there are 4 options of full relationships, the most probable one being a 2nd cousin with a probability of 85%. Selecting “Half relationships” from the drop-down shows 3 additional options having a much lower probability.
Another unique feature of cM Explainer™ is the ability to show MRCA probabilities. Each MRCA probability is the overall probability that you and this DNA Match share a specific most recent common ancestor (MRCA). To view probabilities for MRCA, click the checkbox shown below, marked with a red rectangle. The MRCA probabilities are marked with a green rectangle.
In this example, the MRCA is very likely your great-grandparents at 85% probability. Note that the MRCA is described based on the relationship to you, not your DNA Match. For example, your great-grandparents might be more distant ancestors for your DNA Match, such as great-great-grandparents.
The examples that were shown above are from a case where the ages of you and your DNA Match are known. While cM Explainer™ provides its most accurate relationship predictions when the ages of both individuals are known, it can also predict relationships with probabilities in cases where only one individual’s age is known, or none of the ages are known (unlikely because you always know your own age or the age of a person whose DNA kit you are managing). Some users may choose not to indicate their age in their account, and others may mark their age as private, so the age of a DNA Match is not always known.
Below the list of possible relationships is an explanation of how the predictions were calculated. If only one age is known, it will say so, as in the example below.
