The first publish on this sequence described endogamy, the observe of mating inside a comparatively small group over many generations, such that many 
Pedigree View
A method of assessing pedigree collapse and endogamy is to visualise it in your tree. Nonetheless, the everyday codecs we use for household timber—pedigrees and descendant charts—don’t show the data we want in a manner that’s simple to interpret.
Right here’s an instance by which the ancestors who seem greater than as soon as are circled. Whereas we’re accustomed to this pedigree perspective, with out the added circles, the diploma of endogamy wouldn’t be instantly obvious. What’s extra, a graphic of this sort turns into more and more massive as we add generations, making it tougher to absorb all the info at a look.
Exploring Household Timber
My favourite instrument for visualizing endogamy in a gedcom file is the Exploring Household Timber instrument by Brad Lyon. You’ll be able to learn extra about use it right here.
This graphic exhibits the identical tree as above, however the endogamy is rather more obvious. The “swoops” hint ancestors who seem two or extra instances within the pedigree; the extra swoops, the extra endogamy.
What’s extra, this view can present many extra generations in a compact house. The field marks roughly the seven generations within the pedigree above. This permits us to see the in depth endogamy additional again within the tree, within the 1600s and 1700s. It’s a traditional sample of settlement, when a small inhabitants colonized land removed from their earlier properties and the place marriage companions had been restricted.
The diagram even highlights non-endogamous (or maybe less-endogamous) lineages that married into the inhabitants. These lineages seem as largely vertical branches. On this explicit tree, they embrace French, Irish, and Spanish settlers who married Louisiana’s Acadians within the 1800s.
Tally Your Duplicate Ancestors
What number of of your ancestors seem greater than as soon as in your tree? And what number of instances do they present up? A simple technique to discover this out is with the Tree Completeness and Pedigree Collapse experiences for timber at DNA Painter. (Primary timber are free, however you’ll want a subscription in case your tree goes deeper than 4th nice grandparents.)
The hyperlink to tree completeness is on the prime proper of your tree. As you may see, mine has 255 individuals who seem greater than as soon as. The Pedigree Collapse report names them and tallies what number of instances every particular person seems within the tree.
How A lot Endogamy Is a Lot?
Even the instruments described right here, although, don’t quantify the endogamy. Is it a little bit? Quite a bit? Someplace in between? As we’ll see in a subsequent publish, I think about the instance above to be average endogamy.
That evaluation relies on DNA matches, although, not a tree. Sarcastically, canine breeders have instruments that may calculate the quantity of pedigree collapse, however we don’t have handy instruments to do the identical factor from our gedcoms. (Builders: Trace! Trace!)
Be taught Extra!
Endogamy is the final frontier in genetic family tree. Be taught greatest practices for working with this frequent problem on this upcoming academic alternative. This class will enable you to perceive what endogamy is, why it complicates DNA analyses, gauge it, and a few methods to work most successfully along with your DNA outcomes.
You’ll have alternatives to ask questions throughout and after the speak. Attendance is proscribed to 35 individuals per session, with two classes of the identical materials at present scheduled to accommodate varied schedules (5 PM PDT on 12 April and 10 AM PDT on 13 April). Registered individuals could have entry to the recording for two weeks. Captioning accessible, and a handout is included.
Comply with me on Eventbrite to study upcoming occasions!
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