William Howard devised a simple method for taking two ydna 37 strs and computing a rough estimate for the number of years ago that their most recent comman male ancestor lived. (See his paper deriving the RCC timescale at "https://jogg.info/wp-content/uploads/2021/09/52.013.pdf".) It is simply a scaling of the ordinary pearson correlation coefficent $cor$ of the two strs. $1\ RCC = 10000*(1/cor - 1)$. He proposed based on his data that scaling the RCC by a factor of 43.3 years per 1 RCC gives a reasonable estimate of the years to the most recent common (male) ancestor YMRCA. $$ YMRCA = 43.3*RCC$$ So, you can take your 37 ydna str and compare it to a potential relative's 37 ydna str and get Howard's estimate for how far back before your respective trees shared a male ancestor. |
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