Posts

Reconstructing My Great-Grandparents (As The Creeper Tour Rolls On)

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Kevin and Rolf exhibiting Borland Genetics in Sweden As many readers may be aware, Borland Genetics has been promoting uploads to the site throughout 2022 via a hybrid in-person/virtual string of appearances at industry tradeshows, genealogy society events, genealogy vlogs, etc., all under the penumbra of the "2022 Creeper Tour."  So far, the tour has passed through Baltimore, Cincinnati, Sacramento, Ottawa, Indianapolis, Portland (Oregon),  Skövde (Sweden), and Burbank, and upcoming dates are scheduled for Minneapolis (virtual), Sydney (Australia), Salt Lake City, Richmond, Sandusky, Milwaukee, and finally back to Baltimore (as the Tour extends through 2023). Some of the dates thus far  have been expo hall exhibits with opportunity to meet me in-person and discuss Borland Genetics reconstruction techniques, while others took the form of virtual talks where I presented topics including DNA inheritance, DNA reconstruction, interpreting one's DNA results, the future of DNA

Introducing the Borland Genetics Segment Lab

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  It occurred to me today that I have not yet done a tutorial on how to use the Borland Genetics “Segment Lab” tool.   Introduced as part of last October’s anniversary “Fall Features Release,” it’s one of the newest tools on the site, and probably also one of the most under-utilized.   Hopefully, this demonstration will show how it’s also one of the most valuable tools on the site. The Segment Lab is Borland Genetics’ native chromosome map/phase map editor.   While a far cry from a robust chromosome mapping solution like DNAPainter, it has specialized features that I designed to make our task of ancestor DNA reconstruction easier, and to help maximize the reconstruction coverage of our output ancestor kits. Before we dive into using the tool, I want to point out that the Segment Lab is NOT a tool that creates a phase map from scratch.   At Borland Genetics, that’s what the HIR Mapper does, and when it comes to mapping matches from outside the Borland Genetics platform, DNAPainter i
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Help!   My Segments Are So Sticky! Back in the day, it used to be popular to refer to certain segments as “sticky” when they appeared to be passed down from generation to generation untouched.   That sort of name-calling has reduced greatly now that we have a clearer understanding of the statistical rules that our chromosomes follow as a result of random recombination.   It turns out that the smaller a segment, the more likely it is to escape the chopping block of recombination in each generation and instead either be passed to the child in full or not at all.   Let’s take a look at some numbers and see how this plays out. As our starting point, we’re going to go back to our definition of centiMorgan, as explained in my blog from a few weeks ago about the statistical impossibility of two full siblings not sharing any DNA segments.   If you missed that one, that’s OK, here’s the way I like to think about a cM:   A cM is a unit that denotes a span of a chromosome that has