View Full Version : TMRCA for Major SubClades From L23>L51* & L11* and down into L21

07-17-2013, 08:02 PM
I have posted a Chart of the TMRCA's for the combined Clades L51* & L11* to form a base age in both Coalescence and Founder Modal Ages. I then selected major subclades below L11 and into L21 using the biggest subclades. I separated the two different ages into a Chart which shows the TMRCA and its standard deviation range based on a Confidence Index I selected of 1-Sigma (68.27) instead of the default standard deviation normally calculated which could be more or less. I used 30 years per generation and Bird's Stable STRs. Coalescence of a sampled population age is a corrected generation age to get a 'True' unbiased result. Notice that there will be some overlapping time ranges which is normal and acceptable.

In explaining Coalescent Theory, Magnus Nordborg stated this:

Now consider the random genealogical relationships (i. e., “who begat whom”) that result from reproduction in this setting. These can be represented graphically ... Going forward in time, lineages branch whenever an individual produces two or more offspring, and end when there is no offspring. Going backward in time, lineages coalesce whenever two or more individuals were produced by the same parent. They never end. If we trace the ancestry of a group of individuals back through time, the number of distinct lineages will decrease and eventually reach one, when the most recent common ancestor (MRCA) of the individuals in question is encountered.

Founder's Modal Age is a point where the set of haplotypes converge back to a one original haplotype.

The variance swing experienced in each subclade for Age vs Max Age could be slow growth/bottle neck results in both the Founder's Modal and the Coalescence nodes.

My chart can be found in my Google documents. Adobe Reader required. Download and you can rotate the image to better view on the screen or print it out.



07-18-2013, 11:33 AM
Looking at the figures for DF49* I'm reminded of the Frankenstein picture Rich posted on Facebook as a possible explanation for DF49's origin : )