Recently I was at a meeting with some fellow retired Naval Officers. The subject came around to a concept several of us had learned at the National Defense University in Washington, DC.

There is now a Wikipedia Article about VUCA – Volatility, Uncertainty, Complexity, Ambiguity. It was coined to refer to wars, but was later applied to many other situations. As I thought about it, VUCA can be used to describe atDNA.

1. Volatility – The basis of human DNA, the “Build” is always being updated and changed – it was recently changed from Build 36 to Build 37 (by most companies). The chips used to determine SNP values have undergone change. FTDNA reran all of their tests when they changed to the Illumina chip. 23andMe has changed chips (and SNPs) at least twice in the last few years. AncestryDNA significantly changed their matching algorithm recently. There will be more change as newer technology or processes are developed.

2. Uncertainty – Is a shared segment IBD or not? Is a Common Ancestor the genetic ancestor or not? How many cMs should we expect to share with a 4th cousin?

3. Complexity – A matching algorithm may take SNPs from either side. Shared segments may be from either parent’s chromosome. Can it get more complex. Well… sure it can. How distant could the Common Ancestor be? Does the shared segment span two Common Ancestors or not? Which ancestors are not genetic ancestors? Which genetic ancestors passed down segments above a matching threshold? How does endogamy affect our shared segments?

4. Ambiguity – The cM measurements are based on an average of observed values for crossovers by males and females. Base pairs span areas of chromosomes that have not been sequenced. There is no sign post to indicate where a segment from an ancestor starts or stops – so shared segments are often reported as longer or shorter than they really are. Company algorithms are different – what is the criterial for a Match? How do they handle no-calls?

I think the VUCA acronym describes atDNA pretty well…

06Z Segment-ology: VUCA DNA by Jim Bartlett 20150823