Thursday, 3 December 2015

Mutation History Tree for Lineage II

What are Mutation History Trees?

These trees are like family history trees but the "family" part has been replaced with "mutations", or rather, has been augmented with mutations. In other words, when the known ancestors run out, DNA mutations still allow us to keep on going back in time and thus identify the branching pattern within the overall group for each Lineage. It also allows us to estimate when the different branching points between group members occurred. This helps you see where you sit in the overall group and who is most closely related to you. And this in turn helps foster collaboration between project members which will hopefully lead to breakthroughs in your genealogical research.

Copies of Older Versions will be archived so that we can keep track of the evolution of the trees over time as more people join the project and upgrade their tests.

Lineage II (North Tipperary group)

Below is the Mutation History Tree for Lineage II. This will be constantly updated as more project members join. You can click on the image to enlarge it and then right click again and "Open in a New Window" (Mac) to make it even larger. Alternatively, you may find it easier to download the image (simply right click on the image and choose download). Or a pdf version of the tree is available in our Facebook group here - this has the added advantage that it is searchable.

But first, you will probably need some explanation of what you are looking at.
  • Starting at the top, it follows the mutations in STR markers from subclade Z255 (characterised by the Z255 mutation which formed about 4300 years ago [1]) down in time through various subclades (Z16437/Z16439 and Z16438, both formed about 1500 years ago) to the Gleeson MRCA (Most Recent Common Ancestor of Lineage II) and then down to the modern day Gleeson males who have tested in Lineage II.
  • The tree is based on both SNP and STR data. SNPs are cut & pasted from Alex Williamson's Big Tree. STRs are extracted from our project's DNA Results page
  • Fluxes software was used to create an initial STR-based branching pattern. SNPs were added and helped to anchor the upper reaches of the tree.
  • Branching points have time estimates in generations back from the present. Allowing 30 years per generation gives a good indication of the number of years back to a particular branching point from the testers date of birth (usually between 1930-1950).
  • STR mutations are written as: marker number, old value - new value
  • Back Mutations are highlighted in yellow. Parallel Mutations are written in red text.
  • Branches have been numbered (in bold royal blue).
  • The number of Markers Tested by each participant is indicated as 25, 37, 67 or 111. BY stands for the Big Y test.
  • FTDNA Kit numbers, Project G-numbers, and initials represent each of the participants.
  • Country of present residence indicates the extent of the Gleeson diaspora.
  • Gleeson Ancestral Lines are indicated for each participant by the green boxes with a crude timeline to the side.
  • MDKA Profiles list possible MPRs (Markers of Potential Relatedness) which may be particularly useful information for collaboration between project members (especially birth location, family nickname or agnomen, & occasional other major distinguishing features).
Lineage II Mutation History Tree Nov 2015

You can watch a video of the Journey of Discovery I took in creating this tree below.



What does it tell us? 

The current starting point for Lineage II is estimated to be more than 25 generations ago. That's about  750 years before the average tester's date of birth. If we assume that to be 1950, and allowing 30 years per generation, then we are looking at an origin for Lineage II about 1200 AD. This estimate may change as more people join the project.

The Glisson branch (G-68, 411177) is an ancient branch, going back about 21 generations ago = 630 yrs = 1300 AD.

The most closely related branches are 8, 5, 4, & 12. These members are actively exploring their connection using traditional genealogical records.

As regards the process of building this MHT ...
  • The 37 marker test (Y-DNA-37) is sufficient to allocate new participants to Lineage II, but is not adequate for giving accurate estimates of TMRCAs  (and hence branching points)
  • 67 or 111 STR markers are needed for accurate dating of the branching points
  • STRs better define the branching pattern than SNPs. Thus far, SNP markers appear to be more useful for defining the more upstream branches of the tree and STR markers the more downstream branches. This may change over time.
  • In order to improve the accuracy of this MHT, we need a) more people to test; b) more people to upgrade to 111 markers; and c) more people to SNP test
  • In due course, it is hoped that a Lineage II-Specific SNP Marker Panel will be developed (for about $120). This will hopefully save new members money on SNP testing.
As series of blog posts will follow in due course exploring the various steps involved in this creation process in greater depth.

Maurice Gleeson
Dec 2015
Sources:
[1] estimates carry a wide margin of error. Current estimates are found here - http://www.yfull.com/tree/R-Z255/ 







No comments:

Post a Comment