The chromosome maps below were created using the technique of Visual Phasing, which can be done if the autosomal DNA test results of three or more siblings are available.
Visual Phasing maps the maternal and paternal chromosomes to the four grandparents of the individuals who took the DNA tests. In this case, the chromosomes of Mert, Dave and Sherry were mapped to their four grandparents:
The genetic genealogy websites My Heritage, Family Tree DNA, Gedmatch, and 23 and Me provide the users with the location of DNA segments that they share with their DNA matches. Ancestry DNA does not provide this data, so genealogists often transfer their test results to the free site Gedmatch or one of the other sites, so that they can view the actual matching segments.
If three siblings are not available for testing, users can still take advantage of segment mapping by using DNAPainter.com, an innovative website where users can paint segments of their matches on a colorful graph of their 22 chromosomes.