Chromosome Analysis

This view is designed to assist the user in locating "gaps" in their overall chromosome map, and through interaction with this page, filtering the Chromosome Browser (F7) display to relatives who are within one of those Gaps.

This differs from the existing Segment Maps in a crucial way. The Segment Maps show us the known by groups, and can help us to filter those segments. This feature allows us to clearly see the still unknown and filter to those areas.

This tool may prove to be more useful to those users who already have many known cousins in their databases. New users may not see much here to begin with, but it will develop and fill out more with time.

The green bar Group names are taken from the Profile's Ancestor list, and represent the Profile's Maternal grandparents and their Paternal grandparents.

Clicking on the plus sign next to these will display all currently identified ancestral group names on that branch of the tree. Clicking on the plus sign next to any of the grey bar group names will show you the relatives associated with those groups.

The Ancestor shown next to the group name is the ancestor from whom the profile descends that has that group name, so for the green bar group names, these are the profile's parents.

To appear on this view, a segment must have had a MRCA ancestor assigned to it, giving it a side and a group name. It does not have to have the status of MRCA, although it is recommended that this status is also applied to known relatives.

If clicking on a green lined plus sign does not change the display, then the current profile has no assigned segments for that chromosome.

Any relative who has an MRCA assigned that is the profile's self (gen 1) or parent (gen 2), will not show up on this view. This means you will not see your children, siblings, nieces or nephews, aunts or uncles, or 1st cousins, or their descendants. Only relatives who have a generation 3 or higher assigned MRCA will be displayed. This is to avoid potential confusion of gaps overlapping known close relatives who share two or more ancestors with the profile person.

To change the chromosome being viewed, right click (Control-Click on Mac) and use the "Select Chromosome" menu. Clicking on a heading name will sort the columns accordingly. This sort carries over to other chromosomes in the same view.

Hovering over a match name will display the MRCA note for that relative.

Using this tool to help us

In the next image, we can see that both the Maternal and Paternal sides of this chromosome have had some areas identified, but that there are also some Gaps, as indicated by the word ---Gap--- under the Group heading, and the black bar lengths on the right hand side.

Double clicking on the group name "--Gap--" will take you to the Chromosome Browser for this section of the chromosome you are currently viewing. It will also filter your view to the show just relatives with appropriate side set plus unknown relatives.

If after some investigation, you find that you can identify a branch of your tree, but not an MRCA, you may wish to add a Partition to your chromosome Gaps view.

In the example, I'm going to add a Partition to this gap.

I had originally double clicked on this gap to show me who I should be looking at in more detail, and I found I had four relatives with decent segments that I could investigate.

On reviewing the matches, if I find that one or more matches have enough information to indicate a branch of tree, then I can assign a side to that match, and right click and select "Create Partition".

The message that a partition has been created will appear.

Note: You must assign either a Maternal or Paternal side to a segment to create a partition. You can select multiple segments at once to create a partition, GDAT will determine the start and end points of your segment. You must also only have the desired side and unknown segments visible when creating a partition.

When I return to the Chromosome Gaps view, I can now see this new partition has been created, and it has shortened the default gap accordingly. In this case, we now have two shorter gaps, one before the partition and one after the partition.

User created partitions take their name from the group name currently assigned to that relative. If there is no group name, the name is empty. You can click in the name (or the space) and rename it if you wish.

User created partitions have a background colour of purple, and the generation level is marked as -1 to help distinguish them from automatically created partitions.

Click on a Start or End Point of a User Created partition to expand or contract it as your research develops. You will need to reload the page to see adjacent gaps adjust accordingly.

Right click (Control-Click on Mac) on a user created group to delete it.

Right click (Control-Click on Mac) on a program defined group name to access more features.

Marking a segment as confirmed will give a background colour of yellow to that segment only. This only applies the confirmation to this segment. Other segments of the same group name are left untouched.

Double click on a relative's name to access their F1-F5 pages.