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Q: What is YFull's subclade age methodology?

A: For each subclade in the YTree, YFull provides information about any currently equivalent SNPs, the subclade "formed" age and TMRCA and many additional details in an "info" pop-up table (activated by left clicking or tapping on "info"). The pop-up table provides TMRCA calculation information, subclade "currently defining" SNP information and STR information for the test samples that are part of the subclade. The FAQ: What is YFull's age estimation methodology? provides background details.

The following definitions and methodologies apply:

Subclade SNP name: The subclade SNP name, highlighted in green, is chosen by YFull. If there are other SNPs currently equivalent to the subclade SNP name, they are listed to the right of the subclade SNP name (and some of these may be listed as +X SNPs and viewable by hovering your pointer over +X SNPs). The subclade SNP name and the currently equivalent SNPs are also listed in the SNPs tab of the "info" pop-up table. If YFull has named one or more of the equivalent SNPs (Yxxxxxx series), it will choose the Y series SNP with the lowest number as the subclade SNP name. If it has not named any of the equivalent SNPs, it will use an existing name determined on a alphabetical and lowest number basis.

Subclade "formed" age: The TMRCA of a subclade is used as the "formed" age of each branch of the subclade. In other words, the formed age of a branch is the same as the TMRCA of the "parent" subclade of the branch.

Subclade TMRCA: TMRCA means "time to most recent common ancestor." Information about the TMRCA calculation is provided below in the explanation of the "info" pop-up table. If a subclade has a very recent TMRCA age, such as 100 ybp (years before present), the SNPs and STRs related to the subclade (as disclosed in the "info" pop-up table) may be considered as a "family signature."

Confidence Interval pop-up window: Confidence interval (or CI) information for the formed age and TMRCA of a subclade is viewable by hovering your pointer over the subclade formed age and TMRCA. The format for this information is "Formed CI xx% yyyy <-> zzzz ybp, TMRCA CI aa% bbbb <-> cccc ybp." YFull developed its own statistical analysis computer script in order to calculate the confidence intervals.

TMRCA in "info" pop-up table:
* The general rule is that the TMRCA of a subclade is equal to the average age (after rounding) shown in the yellow horizontal bar. In any situations where the general rule is not followed YFull will add an explanatory note at the bottom of the table. YFull's rounding rules: An age of less than 500 ybp is rounded to the nearest "25" (e.g., 267 becomes 275); an age of 500 to 1999 is rounded to the nearest "50" (e.g., 1267 becomes 1250); and an age of 2000 or more is rounded to the nearest "100" (e.g., 2267 becomes 2300).

* The subclade "ybp" (years before the present) in the yellow horizontal bar is the average of the ages of the branches and samples (if any) highlighted in green in the Branch ID column, as shown in the yellow bar "Formula".

* Number of SNPs column: For a branch, the number in this column is the average of the numbers reported for the samples in the branch. For a sample, the number in this column is the total of the Known SNPs and Novel SNPs located between the subclade and the present.
Branch numbers are averages of the numbers given for all of the samples in the branch (but the table will be limited to only the first 100 samples listed in order of "id" number).

* The coverage and the formulas used in the table to calculate "age by this line only" are discussed in the FAQ: What is YFull's age estimation methodology?

SNPs in "info" pop-up table: The SNPs currently defining the subclade are listed here, together with their YFull quality rating. SNP details are available by using the magnifying glass icon located left of the SNP name.

STRs in "info" pop-up table: The information in the top part of this table is an excerpt from the STR variants report. See FAQ: What is YFull's STR variant methodology? Following the STR variants excerpt is a STR haplotype constructed by YFull from the STR reports of the YFxxxxx samples that are part of the subclade.

Last updated on March 28 2018.