Maternal Lineage

There are a lot of blanks to be filled.

This is the map of all direct ancestors up to seven generations back.

Generations mapping Ashkenazim/Sephardi heritage:

1. Mother
2. Grandmother Riva Shapiro (Raisa Lipatova), 1902-1981
3. Great-grandfather Lieber Shapiro (died about 1910) and great-grandmother _ _ _ _ Shapiro (died about 1903)
4. four generations back; number of ancestors – 4;
5. five generations back; number of ancestors – 8;
6. six generations back; number of ancestors – 16;
7. seven generations back; number of ancestors – 32, etc.

First number represents the generation, other numbers are unique IDs. Even numbers are for male and grayed odd numbers are for female ancestors.

Branch 40-50-60-70 is direct Shapiro paternal line.

Branch 31-41-51-61-71 is direct maternal line carrying K2a2a1 haplogroup. Oldest known female ancestor on that line (51) possibly lived in Dinaburg in Latgalia (Russian Empire) around 1850-1870.

One out of eight 5th generation ancestors was apparently carrying 100% Sephardi blood. Bigger triangle represents tentative Rodrigo line which ended when female descendant 55 married with a Shapiro. Alternatively, it can be any other ancestor representing fifth generation except (maybe) direct paternal Shapiro line (40-50-60-70), e.g. it can be 52, 53, 54, 56 or 57.

For that ancestor to be 100% Sephardi all of his or her own ancestors earlier than 1850 must have been exclusively of Sephardi descent.

Some Spanish sources do list Shapiro as a known Sephardi name. It could be also linked with Sephardi lineage through the Netherlands that were part of the Kingdom of Spain when Sephardi Jews were expelled in 1492. 

Smaller triangle represents another 100% Sephardi ancestor from the 7th generation; it can be any of the 24 remaining 7th generation ancestors (excluding the bigger Sephardi triangle linked with the 5th generation and another line ascending to direct maternal ancestor 51, who had 100% Ashkenazim lineage).

So that my maternal grandmother could carry 16% of Sephardi blood, several of the remaining 23 ancestors seven generations ago must have carried the remaining 28%, meaning that their ancestors were partially of Sephardi descent (e.g. there were more ancestors from Spain down the line before they eventually mixed with Ashkenazim).  

Explanation:

If one out of eight 5th generation ancestors was 100% Sephardi he/she could pass only half to the children. So, the 4th generation would carry 50%, 3rd generation - 25%, 2nd generation (my grandmother) -12%. Then 6% and 3% to my mother and myself. If percentage is higher it means there was more than one line that inherited Sephardi blood but further down the generations.