Dating bases explained

Areas of high diversity, in this case, Y SNPs, may differ from each other.

It’s those differences that matter to us as genealogists.

dating bases explained-55

From this model, we know that we can align most people’s results on the green locations where everyone matches everyone else because we are all human.

The other locations may be the same or different, but they can’t be aligned reliably by relying on the map.

In order to find those differences, we must be able to line up the genomes of the various people tested, on top of each other, so that we can measure from the locations that are the same. All 4 people in this table above match exactly on locations 1-7, 9- 10 and 13-15.

Locations 8, 11 and 12 are areas that are more unstable, meaning that the people are not the same at that location, although they may not match each other, hence the different colored cells.

The Big Y is the logical extension of STR testing (panels 37, 67 and 111), which focus on genealogical matches, closer in time, instead of haplogroup era matches.

STR locations mutate more rapidly than SNPs, so the STR test is more useful for genealogists, or at least represent an entry point into Y DNA testing.

You can read more about the complexity of this topic here and a good article, here.

A New Model The challenge is that between 20, new locations were discovered in previously unmapped areas of the genome.

The Big Y test is how the Y DNA phylotree has been expanded from a few hundred locations a few years ago to more than 78,000, and along with that comes our understanding of the migration patterns of our ancestors.

We’re still learning, every single day, so testing new people continues to be important.

You can read more about this here, here, here and here, if you really want to dig in.

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